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SEC Schedule, Article 12-28, Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands | 12 Months Ended |  |  |
--- | --- | --- | --- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Encumbrances | [1] | $ 3,272,368 |  |  |
Original Cost |  |  |  |  |
Original Land |  | 5,373,987 |  |  |
Original Building |  | 14,755,092 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,615,135 |  |  |
Land and Improvements | [2] | 5,571,327 |  |  |
Building and Improvements | [3] | 19,044,812 |  |  |
Land held for development | [4] | 721,501 | $ 560,355 |  |
Development and Construction in Progress |  | 406,574 | 894,172 |  |
Total |  | 25,744,214 | 24,108,220 | $ 23,303,303 | $ 22,844,697
Accumulated Depreciation |  | 6,260,992 | 5,848,183 | 5,501,637 | 5,239,179
Furniture, Fixtures and Equipment |  | 50,310 | 51,695 |  |
Aggregate cost for tax purpose |  | 23,100,000 |  |  |
Real Estate Aggregate Accumulated Depreciation For Tax Purposes |  | 5,000,000 |  |  |
Right-of-use assets - finance leases |  | 237,510 | 237,507 |  |
Right of use assets - operating leases |  | $ 167,351 | 169,778 |  |
Maximum [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Real Estate and Accumulated Depreciation, Life Used for Depreciation |  | 40 years |  |  |
Furniture, fixtures, and equipment |  |  |  |  |
Original Cost |  |  |  |  |
Accumulated Depreciation Related to Furniture, Fixtures and Equipment |  | $ 37,090 |  |  |
Land and Land Improvements [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Right-of-use assets - finance leases |  | 214,165 |  |  |
Right of use assets - operating leases |  | 167,351 |  |  |
Buildings and improvements |  |  |  |  |
Original Cost |  |  |  |  |
Right-of-use assets - finance leases |  | 23,345 |  |  |
767Fifth Avenue (the General Motors Building) | Office Building [Member] |  |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Encumbrances |  | 2,284,510 |  |  |
Original Cost |  |  |  |  |
Original Land |  | 1,796,252 |  |  |
Original Building |  | 1,532,654 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 325,762 |  |  |
Land and Improvements |  | 1,796,252 |  |  |
Building and Improvements |  | 1,858,416 |  |  |
Total |  | 3,654,668 |  |  |
Accumulated Depreciation |  | $ 457,344 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Prudential Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 92,077 |  |  |
Original Building |  | 948,357 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 718,028 |  |  |
Land and Improvements |  | 115,639 |  |  |
Building and Improvements |  | 1,510,834 |  |  |
Land held for development |  | 231 |  |  |
Development and Construction in Progress |  | 131,758 |  |  |
Total |  | 1,758,462 |  |  |
Accumulated Depreciation |  | $ 721,498 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Embarcadero Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 179,697 |  |  |
Original Building |  | 847,410 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 499,451 |  |  |
Land and Improvements |  | 195,986 |  |  |
Building and Improvements |  | 1,330,572 |  |  |
Total |  | 1,526,558 |  |  |
Accumulated Depreciation |  | $ 736,748 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
399 Park Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 339,200 |  |  |
Original Building |  | 700,358 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 393,821 |  |  |
Land and Improvements |  | 354,107 |  |  |
Building and Improvements |  | 1,079,272 |  |  |
Total |  | 1,433,379 |  |  |
Accumulated Depreciation |  | $ 445,239 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
601 Lexington Avenue | Office Building [Member] |  |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Encumbrances |  | $ 987,858 |  |  |
Original Cost |  |  |  |  |
Original Land |  | 241,600 |  |  |
Original Building |  | 494,782 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 515,644 |  |  |
Land and Improvements |  | 289,639 |  |  |
Building and Improvements |  | 962,387 |  |  |
Total |  | 1,252,026 |  |  |
Accumulated Depreciation |  | $ 348,892 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Salesforce Tower | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 200,349 |  |  |
Original Building |  | 946,205 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 7,462 |  |  |
Land and Improvements |  | 200,349 |  |  |
Building and Improvements |  | 953,667 |  |  |
Total |  | 1,154,016 |  |  |
Accumulated Depreciation |  | $ 129,281 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
200 Clarendon Street and Garage | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 219,543 |  |  |
Original Building |  | 667,884 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 235,129 |  |  |
Land and Improvements |  | 250,512 |  |  |
Building and Improvements |  | 872,044 |  |  |
Total |  | 1,122,556 |  |  |
Accumulated Depreciation |  | $ 310,318 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
250 West 55th Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 285,263 |  |  |
Original Building |  | 603,167 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 51,800 |  |  |
Land and Improvements |  | 285,263 |  |  |
Building and Improvements |  | 654,967 |  |  |
Total |  | 940,230 |  |  |
Accumulated Depreciation |  | $ 179,143 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
100 Federal Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 131,067 |  |  |
Original Building |  | 435,954 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 119,341 |  |  |
Land and Improvements |  | 131,067 |  |  |
Building and Improvements |  | 555,295 |  |  |
Total |  | 686,362 |  |  |
Accumulated Depreciation |  | $ 157,368 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Madison Centre | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 104,641 |  |  |
Original Building |  | 564,336 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,879 |  |  |
Land and Improvements |  | 104,641 |  |  |
Building and Improvements |  | 567,215 |  |  |
Total |  | 671,856 |  |  |
Accumulated Depreciation |  | $ 13,611 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Times Square Tower | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 165,413 |  |  |
Original Building |  | 380,438 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 121,437 |  |  |
Land and Improvements |  | 169,193 |  |  |
Building and Improvements |  | 498,095 |  |  |
Total |  | 667,288 |  |  |
Accumulated Depreciation |  | $ 241,474 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Carnegie Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 142,666 |  |  |
Original Building |  | 316,856 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 168,261 |  |  |
Land and Improvements |  | 94,243 |  |  |
Building and Improvements |  | 476,990 |  |  |
Land held for development |  | 55,919 |  |  |
Development and Construction in Progress |  | 631 |  |  |
Total |  | 627,783 |  |  |
Accumulated Depreciation |  | $ 252,390 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
125 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 126,364 |  |  |
Original Building |  | 433,662 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 58 |  |  |
Land and Improvements |  | 126,364 |  |  |
Building and Improvements |  | 433,720 |  |  |
Total |  | 560,084 |  |  |
Accumulated Depreciation |  | $ 4,503 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Atlantic Wharf | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 63,988 |  |  |
Original Building |  | 454,537 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 24,158 |  |  |
Land and Improvements |  | 63,988 |  |  |
Building and Improvements |  | 478,695 |  |  |
Total |  | 542,683 |  |  |
Accumulated Depreciation |  | $ 171,876 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Reston Next | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 2,901 |  |  |
Original Building |  | 525,277 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 0 |  |  |
Land and Improvements |  | 2,901 |  |  |
Building and Improvements |  | 525,277 |  |  |
Total |  | 528,178 |  |  |
Accumulated Depreciation |  | $ 15,293 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
599 Lexington Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 81,040 |  |  |
Original Building |  | 100,507 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 245,609 |  |  |
Land and Improvements |  | 87,852 |  |  |
Building and Improvements |  | 339,304 |  |  |
Total |  | 427,156 |  |  |
Accumulated Depreciation |  | $ 182,121 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Fountain Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 56,853 |  |  |
Original Building |  | 306,298 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 39,288 |  |  |
Land and Improvements |  | 56,853 |  |  |
Building and Improvements |  | 345,586 |  |  |
Total |  | 402,439 |  |  |
Accumulated Depreciation |  | $ 104,864 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
510 Madison Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 103,000 |  |  |
Original Building |  | 253,665 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 31,682 |  |  |
Land and Improvements |  | 103,000 |  |  |
Building and Improvements |  | 285,347 |  |  |
Total |  | 388,347 |  |  |
Accumulated Depreciation |  | $ 95,520 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
325 Main Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 21,596 |  |  |
Original Building |  | 312,492 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 0 |  |  |
Land and Improvements |  | 21,596 |  |  |
Total |  | 334,088 |  |  |
Accumulated Depreciation |  | $ 4,308 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
680 Folsom Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 72,545 |  |  |
Original Building |  | 219,766 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 8,026 |  |  |
Land and Improvements |  | 72,545 |  |  |
Building and Improvements |  | 227,792 |  |  |
Total |  | 300,337 |  |  |
Accumulated Depreciation |  | $ 72,414 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
145 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 121 |  |  |
Original Building |  | 273,013 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 26,184 |  |  |
Land and Improvements |  | 23,367 |  |  |
Building and Improvements |  | 275,951 |  |  |
Total |  | 299,318 |  |  |
Accumulated Depreciation |  | $ 26,881 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
2200 Pennsylvania Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 183,541 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 113,108 |  |  |
Land and Improvements |  | 104,329 |  |  |
Building and Improvements |  | 192,320 |  |  |
Total |  | 296,649 |  |  |
Accumulated Depreciation |  | $ 71,410 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
South of Market and Democracy Tower | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,603 |  |  |
Original Building |  | 237,479 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 28,991 |  |  |
Land and Improvements |  | 13,687 |  |  |
Building and Improvements |  | 266,386 |  |  |
Total |  | 280,073 |  |  |
Accumulated Depreciation |  | $ 98,665 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Bay Colony Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,789 |  |  |
Original Building |  | 148,451 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 87,804 |  |  |
Land and Improvements |  | 18,789 |  |  |
Building and Improvements |  | 231,828 |  |  |
Land held for development |  | 4,427 |  |  |
Total |  | 255,044 |  |  |
Accumulated Depreciation |  | $ 105,172 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
535 Mission Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 40,933 |  |  |
Original Building |  | 148,378 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,852 |  |  |
Land and Improvements |  | 40,934 |  |  |
Building and Improvements |  | 152,229 |  |  |
Total |  | 193,163 |  |  |
Accumulated Depreciation |  | $ 42,776 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Mountain View Research Park | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 95,066 |  |  |
Original Building |  | 68,373 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 21,270 |  |  |
Land and Improvements |  | 95,066 |  |  |
Building and Improvements |  | 89,643 |  |  |
Total |  | 184,709 |  |  |
Accumulated Depreciation |  | $ 28,575 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Reservoir Place | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,605 |  |  |
Original Building |  | 104,124 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 55,359 |  |  |
Land and Improvements |  | 20,108 |  |  |
Building and Improvements |  | 156,915 |  |  |
Land held for development |  | 1,065 |  |  |
Total |  | 178,088 |  |  |
Accumulated Depreciation |  | $ 85,394 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
1330 Connecticut Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 25,982 |  |  |
Original Building |  | 82,311 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 38,047 |  |  |
Land and Improvements |  | 27,135 |  |  |
Building and Improvements |  | 119,205 |  |  |
Total |  | 146,340 |  |  |
Accumulated Depreciation |  | $ 48,273 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
One Freedom Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 9,929 |  |  |
Original Building |  | 84,504 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 51,743 |  |  |
Land and Improvements |  | 11,293 |  |  |
Building and Improvements |  | 134,883 |  |  |
Total |  | 146,176 |  |  |
Accumulated Depreciation |  | $ 66,084 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
880 Winter Street [Member] | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 15,597 |  |  |
Original Building |  | 37,255 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 91,537 |  |  |
Land and Improvements |  | 15,597 |  |  |
Building and Improvements |  | 128,792 |  |  |
Total |  | 144,389 |  |  |
Accumulated Depreciation |  | $ 2,560 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Kingstowne Towne Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,021 |  |  |
Original Building |  | 109,038 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,822 |  |  |
Land and Improvements |  | 18,062 |  |  |
Building and Improvements |  | 112,819 |  |  |
Total |  | 130,881 |  |  |
Accumulated Depreciation |  | $ 52,543 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
140 Kendrick Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,095 |  |  |
Original Building |  | 66,905 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 42,528 |  |  |
Land and Improvements |  | 19,092 |  |  |
Building and Improvements |  | 102,625 |  |  |
Development and Construction in Progress |  | 5,811 |  |  |
Total |  | 127,528 |  |  |
Accumulated Depreciation |  | $ 41,627 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Shady Grove Innovation District [Member] | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 52,030 |  |  |
Original Building |  | 64,212 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 7,219 |  |  |
Land and Improvements |  | 26,834 |  |  |
Building and Improvements |  | 34,988 |  |  |
Land held for development |  | 61,639 |  |  |
Total |  | 123,461 |  |  |
Accumulated Depreciation |  | $ 3,319 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
One and Two Reston Overlook | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 16,456 |  |  |
Original Building |  | 66,192 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 40,516 |  |  |
Land and Improvements |  | 16,179 |  |  |
Building and Improvements |  | 106,985 |  |  |
Total |  | 123,164 |  |  |
Accumulated Depreciation |  | $ 57,631 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Weston Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 25,753 |  |  |
Original Building |  | 92,312 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 968 |  |  |
Land and Improvements |  | 25,854 |  |  |
Building and Improvements |  | 93,179 |  |  |
Total |  | 119,033 |  |  |
Accumulated Depreciation |  | $ 38,385 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
17Fifty Presidents Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 113,362 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 162 |  |  |
Land and Improvements |  | 0 |  |  |
Building and Improvements |  | 113,524 |  |  |
Total |  | 113,524 |  |  |
Accumulated Depreciation |  | $ 12,232 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Discovery Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 11,198 |  |  |
Original Building |  | 71,782 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 21,618 |  |  |
Land and Improvements |  | 12,533 |  |  |
Building and Improvements |  | 92,065 |  |  |
Total |  | 104,598 |  |  |
Accumulated Depreciation |  | $ 54,116 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
355 Main Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,863 |  |  |
Original Building |  | 53,346 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 25,418 |  |  |
Land and Improvements |  | 21,173 |  |  |
Building and Improvements |  | 76,454 |  |  |
Total |  | 97,627 |  |  |
Accumulated Depreciation |  | $ 34,399 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
10 CityPoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,953 |  |  |
Original Building |  | 85,752 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,406 |  |  |
Land and Improvements |  | 2,290 |  |  |
Building and Improvements |  | 91,821 |  |  |
Total |  | 94,111 |  |  |
Accumulated Depreciation |  | $ 20,616 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Two Freedom Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,930 |  |  |
Original Building |  | 77,739 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 317 |  |  |
Land and Improvements |  | 15,420 |  |  |
Building and Improvements |  | 76,566 |  |  |
Total |  | 91,986 |  |  |
Accumulated Depreciation |  | $ 35,850 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
200 West Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 16,148 |  |  |
Original Building |  | 24,983 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 49,264 |  |  |
Land and Improvements |  | 16,813 |  |  |
Building and Improvements |  | 73,265 |  |  |
Land held for development |  | 317 |  |  |
Total |  | 90,395 |  |  |
Accumulated Depreciation |  | $ 23,428 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
90 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 19,104 |  |  |
Original Building |  | 52,078 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 18,876 |  |  |
Land and Improvements |  | 20,785 |  |  |
Building and Improvements |  | 69,273 |  |  |
Total |  | 90,058 |  |  |
Accumulated Depreciation |  | $ 29,294 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
153 & 211 Second Avenue [Member] | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 33,233 |  |  |
Original Building |  | 55,940 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 202 |  |  |
Land and Improvements |  | 33,233 |  |  |
Building and Improvements |  | 55,940 |  |  |
Land held for development |  | 202 |  |  |
Total |  | 89,375 |  |  |
Accumulated Depreciation |  | $ 4,808 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
230 CityPoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,189 |  |  |
Original Building |  | 49,823 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 24,604 |  |  |
Land and Improvements |  | 13,807 |  |  |
Building and Improvements |  | 73,809 |  |  |
Total |  | 87,616 |  |  |
Accumulated Depreciation |  | $ 38,306 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
20 Citypoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 4,887 |  |  |
Original Building |  | 72,764 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 7,072 |  |  |
Land and Improvements |  | 4,887 |  |  |
Building and Improvements |  | 79,836 |  |  |
Total |  | 84,723 |  |  |
Accumulated Depreciation |  | $ 9,606 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Waltham Weston Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 10,385 |  |  |
Original Building |  | 60,694 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 12,859 |  |  |
Land and Improvements |  | 11,097 |  |  |
Building and Improvements |  | 72,841 |  |  |
Total |  | 83,938 |  |  |
Accumulated Depreciation |  | $ 42,839 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
77 CityPoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,847 |  |  |
Original Building |  | 60,383 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 9,701 |  |  |
Land and Improvements |  | 14,023 |  |  |
Building and Improvements |  | 69,908 |  |  |
Total |  | 83,931 |  |  |
Accumulated Depreciation |  | $ 32,578 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Sumner Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 624 |  |  |
Original Building |  | 28,745 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 49,302 |  |  |
Land and Improvements |  | 28,205 |  |  |
Building and Improvements |  | 50,466 |  |  |
Total |  | 78,671 |  |  |
Accumulated Depreciation |  | $ 31,436 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
2440 West El Camino Real | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 16,741 |  |  |
Original Building |  | 51,285 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,391 |  |  |
Land and Improvements |  | 16,741 |  |  |
Building and Improvements |  | 57,676 |  |  |
Total |  | 74,417 |  |  |
Accumulated Depreciation |  | $ 19,375 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
300 Binney Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,080 |  |  |
Original Building |  | 51,262 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,268 |  |  |
Land and Improvements |  | 18,080 |  |  |
Building and Improvements |  | 51,402 |  |  |
Land held for development |  | 1,128 |  |  |
Total |  | 70,610 |  |  |
Accumulated Depreciation |  | $ 18,995 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Reston Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 9,135 |  |  |
Original Building |  | 50,857 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,579 |  |  |
Land and Improvements |  | 10,148 |  |  |
Building and Improvements |  | 55,423 |  |  |
Total |  | 65,571 |  |  |
Accumulated Depreciation |  | $ 33,822 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Wisconsin Place | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 53,349 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 11,204 |  |  |
Land and Improvements |  | 0 |  |  |
Building and Improvements |  | 64,553 |  |  |
Total |  | 64,553 |  |  |
Accumulated Depreciation |  | $ 26,659 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
255 Main Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 134 |  |  |
Original Building |  | 25,110 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 33,597 |  |  |
Land and Improvements |  | 548 |  |  |
Building and Improvements |  | 58,293 |  |  |
Total |  | 58,841 |  |  |
Accumulated Depreciation |  | $ 42,204 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
University Place | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 37,091 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 15,903 |  |  |
Land and Improvements |  | 5,425 |  |  |
Building and Improvements |  | 47,569 |  |  |
Total |  | 52,994 |  |  |
Accumulated Depreciation |  | $ 35,296 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
890 Winter Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,913 |  |  |
Original Building |  | 28,557 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,998 |  |  |
Land and Improvements |  | 13,913 |  |  |
Building and Improvements |  | 35,555 |  |  |
Total |  | 49,468 |  |  |
Accumulated Depreciation |  | $ 5,409 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Capital Gallery | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 4,725 |  |  |
Original Building |  | 29,565 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 9,544 |  |  |
Land and Improvements |  | 8,662 |  |  |
Building and Improvements |  | 35,172 |  |  |
Total |  | 43,834 |  |  |
Accumulated Depreciation |  | $ 22,415 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
North First Business Park | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 23,398 |  |  |
Original Building |  | 13,069 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,288 |  |  |
Land and Improvements |  | 23,378 |  |  |
Building and Improvements |  | 18,377 |  |  |
Total |  | 41,755 |  |  |
Accumulated Depreciation |  | $ 17,270 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
150 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 850 |  |  |
Original Building |  | 25,042 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 15,726 |  |  |
Land and Improvements |  | 1,323 |  |  |
Building and Improvements |  | 40,295 |  |  |
Total |  | 41,618 |  |  |
Accumulated Depreciation |  | $ 16,841 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
105 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,299 |  |  |
Original Building |  | 12,943 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 12,718 |  |  |
Land and Improvements |  | 2,390 |  |  |
Building and Improvements |  | 24,570 |  |  |
Total |  | 26,960 |  |  |
Accumulated Depreciation |  | $ 15,578 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Lexington Office Park | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 998 |  |  |
Original Building |  | 1,426 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 19,842 |  |  |
Land and Improvements |  | 1,263 |  |  |
Building and Improvements |  | 19,551 |  |  |
Land held for development |  | 1,452 |  |  |
Total |  | 22,266 |  |  |
Accumulated Depreciation |  | $ 16,716 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
The Point | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 6,395 |  |  |
Original Building |  | 10,040 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 546 |  |  |
Land and Improvements |  | 6,492 |  |  |
Building and Improvements |  | 10,489 |  |  |
Total |  | 16,981 |  |  |
Accumulated Depreciation |  | $ 2,308 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
690 Folsom Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 3,219 |  |  |
Original Building |  | 11,038 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,877 |  |  |
Land and Improvements |  | 3,219 |  |  |
Building and Improvements |  | 12,915 |  |  |
Total |  | 16,134 |  |  |
Accumulated Depreciation |  | $ 3,838 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
33 Hayden Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 266 |  |  |
Original Building |  | 3,234 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 11,501 |  |  |
Land and Improvements |  | 425 |  |  |
Building and Improvements |  | 14,576 |  |  |
Total |  | 15,001 |  |  |
Accumulated Depreciation |  | $ 7,929 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
The Avant Retail | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,499 |  |  |
Original Building |  | 6,647 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,577 |  |  |
Land and Improvements |  | 1,499 |  |  |
Building and Improvements |  | 9,224 |  |  |
Total |  | 10,723 |  |  |
Accumulated Depreciation |  | $ 3,210 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
92-100 Hayden Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 594 |  |  |
Original Building |  | 6,748 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,297 |  |  |
Land and Improvements |  | 778 |  |  |
Building and Improvements |  | 8,861 |  |  |
Total |  | 9,639 |  |  |
Accumulated Depreciation |  | $ 7,507 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
32 Hartwell Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 168 |  |  |
Original Building |  | 1,943 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,944 |  |  |
Land and Improvements |  | 314 |  |  |
Building and Improvements |  | 8,741 |  |  |
Total |  | 9,055 |  |  |
Accumulated Depreciation |  | $ 3,103 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
250 Binney Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 110 |  |  |
Original Building |  | 4,483 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,593 |  |  |
Land and Improvements |  | 273 |  |  |
Building and Improvements |  | 7,913 |  |  |
Total |  | 8,186 |  |  |
Accumulated Depreciation |  | $ 6,974 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
453 Ravendale Drive | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 5,477 |  |  |
Original Building |  | 1,090 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 677 |  |  |
Land and Improvements |  | 5,477 |  |  |
Building and Improvements |  | 1,767 |  |  |
Total |  | 7,244 |  |  |
Accumulated Depreciation |  | $ 964 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
17 Hartwell Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 26 |  |  |
Original Building |  | 150 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,064 |  |  |
Land and Improvements |  | 65 |  |  |
Building and Improvements |  | 6,175 |  |  |
Total |  | 6,240 |  |  |
Accumulated Depreciation |  | $ 3,530 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
The Skylyne | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 28,962 |  |  |
Original Building |  | 239,077 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,784 |  |  |
Land and Improvements |  | 28,962 |  |  |
Building and Improvements |  | 240,861 |  |  |
Total |  | 269,823 |  |  |
Accumulated Depreciation |  | $ 14,154 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Signature at Reston | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 27,076 |  |  |
Original Building |  | 190,580 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,667 |  |  |
Land and Improvements |  | 27,076 |  |  |
Building and Improvements |  | 192,247 |  |  |
Total |  | 219,323 |  |  |
Accumulated Depreciation |  | $ 23,353 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Proto Kendall Square | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 9,243 |  |  |
Original Building |  | 127,248 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,336 |  |  |
Land and Improvements |  | 9,245 |  |  |
Building and Improvements |  | 130,582 |  |  |
Total |  | 139,827 |  |  |
Accumulated Depreciation |  | $ 14,508 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
The Lofts at Atlantic Wharf | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 3,529 |  |  |
Original Building |  | 54,891 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,356 |  |  |
Land and Improvements |  | 3,529 |  |  |
Building and Improvements |  | 57,247 |  |  |
Total |  | 60,776 |  |  |
Accumulated Depreciation |  | $ 17,174 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Boston Cambridge Marriott | Hotel [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 478 |  |  |
Original Building |  | 37,918 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 32,837 |  |  |
Land and Improvements |  | 1,201 |  |  |
Building and Improvements |  | 69,521 |  |  |
Land held for development |  | 511 |  |  |
Total |  | 71,233 |  |  |
Accumulated Depreciation |  | $ 51,568 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Kendall Center Green Garage | Garage |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 35,035 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,798 |  |  |
Land and Improvements |  | 103 |  |  |
Building and Improvements |  | 41,730 |  |  |
Total |  | 41,833 |  |  |
Accumulated Depreciation |  | $ 17,039 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Kendall Center Yellow Garage | Garage |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,256 |  |  |
Original Building |  | 15,697 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,653 |  |  |
Land and Improvements |  | 1,434 |  |  |
Building and Improvements |  | 17,172 |  |  |
Total |  | 18,606 |  |  |
Accumulated Depreciation |  | $ 7,395 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
Kendall Center Blue Garage | Garage |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,163 |  |  |
Original Building |  | 11,633 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,111 |  |  |
Land and Improvements |  | 1,579 |  |  |
Building and Improvements |  | 13,328 |  |  |
Total |  | 14,907 |  |  |
Accumulated Depreciation |  | $ 13,075 |  |  |
Depreciable Lives (Years) | [5] | (1) |  |  |
2100 Pennsylvania Avenue | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 472,873 |  |  |
Land and Improvements |  | 185,203 |  |  |
Building and Improvements |  | 230,497 |  |  |
Development and Construction in Progress |  | 57,173 |  |  |
Total |  | 472,873 |  |  |
Accumulated Depreciation |  | $ 9,755 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
190 CityPoint (formerly 180 CityPoint) [Member] | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 140,370 |  |  |
Development and Construction in Progress |  | 140,370 |  |  |
Total |  | $ 140,370 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
103 CityPoint | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 44,752 |  |  |
Land held for development |  | 74 |  |  |
Development and Construction in Progress |  | 44,678 |  |  |
Total |  | $ 44,752 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Reston Next Office Phase II | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 22,954 |  |  |
Development and Construction in Progress |  | 22,954 |  |  |
Total |  | $ 22,954 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Reston Next Retail | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,199 |  |  |
Development and Construction in Progress |  | 3,199 |  |  |
Total |  | $ 3,199 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
777 Harrison Street | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 144,647 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 28,239 |  |  |
Building and Improvements |  | 47 |  |  |
Land held for development |  | 172,839 |  |  |
Total |  | 172,886 |  |  |
Accumulated Depreciation |  | $ 20 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Kendall Center Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 148,476 |  |  |
Land held for development |  | 148,476 |  |  |
Total |  | $ 148,476 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Back Bay Station Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 72,957 |  |  |
Land held for development |  | 72,957 |  |  |
Total |  | $ 72,957 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
3625 - 3635 Peterson Way | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 63,206 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,165 |  |  |
Land held for development |  | 68,371 |  |  |
Total |  | $ 68,371 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
North First Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 35,004 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,968 |  |  |
Land held for development |  | 38,972 |  |  |
Total |  | $ 38,972 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Plaza at Almaden | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 38,090 |  |  |
Land held for development |  | 38,090 |  |  |
Total |  | $ 38,090 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Springfield Metro Center | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 19,891 |  |  |
Land held for development |  | 19,891 |  |  |
Total |  | $ 19,891 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
CityPoint South Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 19,693 |  |  |
Land held for development |  | 19,693 |  |  |
Total |  | $ 19,693 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Reston Gateway Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 12,734 |  |  |
Land held for development |  | 12,734 |  |  |
Total |  | $ 12,734 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Weston Quarry | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,249 |  |  |
Land held for development |  | 1,249 |  |  |
Total |  | $ 1,249 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Broad Run Business Park | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,184 |  |  |
Land held for development |  | 1,184 |  |  |
Total |  | $ 1,184 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Reston Overlook Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 80 |  |  |
Land held for development |  | 80 |  |  |
Total |  | $ 80 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership |  |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Encumbrances | [6] | $ 3,272,368 |  |  |
Original Cost |  |  |  |  |
Original Land |  | 5,373,987 |  |  |
Original Building |  | 14,755,092 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,247,621 |  |  |
Land and Improvements | [7] | 5,476,618 |  |  |
Building and Improvements | [8] | 18,772,007 |  |  |
Land held for development | [4] | 721,501 | 560,355 |  |
Development and Construction in Progress |  | 406,574 | 894,172 |  |
Total |  | 25,376,700 | 23,734,833 | 22,926,494 | 22,449,476
Accumulated Depreciation |  | 6,143,384 | 5,736,240 | $ 5,396,111 | $ 5,135,289
Furniture, Fixtures and Equipment |  | 50,310 | 51,695 |  |
Aggregate cost for tax purpose |  | 25,700,000 |  |  |
Real Estate Aggregate Accumulated Depreciation For Tax Purposes |  | 5,600,000 |  |  |
Debt Issuance Costs, Net |  | 27,632 |  |  |
Right-of-use assets - finance leases |  | 237,510 | 237,507 |  |
Right of use assets - operating leases |  | $ 167,351 | $ 169,778 |  |
Boston Properties Limited Partnership | Maximum [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Real Estate and Accumulated Depreciation, Life Used for Depreciation |  | 40 years |  |  |
Boston Properties Limited Partnership | Furniture, fixtures, and equipment |  |  |  |  |
Original Cost |  |  |  |  |
Accumulated Depreciation Related to Furniture, Fixtures and Equipment |  | $ 37,090 |  |  |
Boston Properties Limited Partnership | Land and Land Improvements [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Right-of-use assets - finance leases |  | 214,165 |  |  |
Right of use assets - operating leases |  | 167,351 |  |  |
Boston Properties Limited Partnership | Buildings and improvements |  |  |  |  |
Original Cost |  |  |  |  |
Right-of-use assets - finance leases |  | 23,345 |  |  |
Boston Properties Limited Partnership | 767Fifth Avenue (the General Motors Building) | Office Building [Member] |  |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Encumbrances |  | 2,284,510 |  |  |
Original Cost |  |  |  |  |
Original Land |  | 1,796,252 |  |  |
Original Building |  | 1,532,654 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 325,762 |  |  |
Land and Improvements |  | 1,796,252 |  |  |
Building and Improvements |  | 1,858,416 |  |  |
Total |  | 3,654,668 |  |  |
Accumulated Depreciation |  | $ 457,344 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Prudential Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 92,077 |  |  |
Original Building |  | 948,357 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 658,972 |  |  |
Land and Improvements |  | 100,541 |  |  |
Building and Improvements |  | 1,466,876 |  |  |
Land held for development |  | 231 |  |  |
Development and Construction in Progress |  | 131,758 |  |  |
Total |  | 1,699,406 |  |  |
Accumulated Depreciation |  | $ 702,725 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Embarcadero Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 179,697 |  |  |
Original Building |  | 847,410 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 437,070 |  |  |
Land and Improvements |  | 180,419 |  |  |
Building and Improvements |  | 1,283,758 |  |  |
Total |  | 1,464,177 |  |  |
Accumulated Depreciation |  | $ 716,657 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 399 Park Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 339,200 |  |  |
Original Building |  | 700,358 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 334,213 |  |  |
Land and Improvements |  | 339,200 |  |  |
Building and Improvements |  | 1,034,571 |  |  |
Total |  | 1,373,771 |  |  |
Accumulated Depreciation |  | $ 426,148 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 601 Lexington Avenue | Office Building [Member] |  |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Encumbrances |  | $ 987,858 |  |  |
Original Cost |  |  |  |  |
Original Land |  | 241,600 |  |  |
Original Building |  | 494,782 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 478,558 |  |  |
Land and Improvements |  | 279,281 |  |  |
Building and Improvements |  | 935,659 |  |  |
Total |  | 1,214,940 |  |  |
Accumulated Depreciation |  | $ 337,421 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Salesforce Tower | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 200,349 |  |  |
Original Building |  | 946,205 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 7,462 |  |  |
Land and Improvements |  | 200,349 |  |  |
Building and Improvements |  | 953,667 |  |  |
Total |  | 1,154,016 |  |  |
Accumulated Depreciation |  | $ 129,281 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 200 Clarendon Street and Garage | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 219,543 |  |  |
Original Building |  | 667,884 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 235,129 |  |  |
Land and Improvements |  | 250,512 |  |  |
Building and Improvements |  | 872,044 |  |  |
Total |  | 1,122,556 |  |  |
Accumulated Depreciation |  | $ 310,318 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 250 West 55th Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 285,263 |  |  |
Original Building |  | 603,167 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 51,800 |  |  |
Land and Improvements |  | 285,263 |  |  |
Building and Improvements |  | 654,967 |  |  |
Total |  | 940,230 |  |  |
Accumulated Depreciation |  | $ 179,143 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 100 Federal Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 131,067 |  |  |
Original Building |  | 435,954 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 119,341 |  |  |
Land and Improvements |  | 131,067 |  |  |
Building and Improvements |  | 555,295 |  |  |
Total |  | 686,362 |  |  |
Accumulated Depreciation |  | $ 157,368 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Madison Centre | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 104,641 |  |  |
Original Building |  | 564,336 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,879 |  |  |
Land and Improvements |  | 104,641 |  |  |
Building and Improvements |  | 567,215 |  |  |
Total |  | 671,856 |  |  |
Accumulated Depreciation |  | $ 13,611 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Times Square Tower | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 165,413 |  |  |
Original Building |  | 380,438 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 83,458 |  |  |
Land and Improvements |  | 159,694 |  |  |
Building and Improvements |  | 469,615 |  |  |
Total |  | 629,309 |  |  |
Accumulated Depreciation |  | $ 229,310 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Carnegie Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 142,666 |  |  |
Original Building |  | 316,856 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 153,298 |  |  |
Land and Improvements |  | 90,501 |  |  |
Building and Improvements |  | 465,769 |  |  |
Land held for development |  | 55,919 |  |  |
Development and Construction in Progress |  | 631 |  |  |
Total |  | 612,820 |  |  |
Accumulated Depreciation |  | $ 247,525 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 125 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 126,364 |  |  |
Original Building |  | 433,662 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 58 |  |  |
Land and Improvements |  | 126,364 |  |  |
Building and Improvements |  | 433,720 |  |  |
Total |  | 560,084 |  |  |
Accumulated Depreciation |  | $ 4,503 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Atlantic Wharf | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 63,988 |  |  |
Original Building |  | 454,537 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 24,158 |  |  |
Land and Improvements |  | 63,988 |  |  |
Building and Improvements |  | 478,695 |  |  |
Total |  | 542,683 |  |  |
Accumulated Depreciation |  | $ 171,876 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Reston Next | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 2,901 |  |  |
Original Building |  | 525,277 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 0 |  |  |
Land and Improvements |  | 2,901 |  |  |
Building and Improvements |  | 525,277 |  |  |
Total |  | 528,178 |  |  |
Accumulated Depreciation |  | $ 15,293 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 599 Lexington Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 81,040 |  |  |
Original Building |  | 100,507 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 218,367 |  |  |
Land and Improvements |  | 81,040 |  |  |
Building and Improvements |  | 318,874 |  |  |
Total |  | 399,914 |  |  |
Accumulated Depreciation |  | $ 173,396 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Fountain Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 56,853 |  |  |
Original Building |  | 306,298 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 39,288 |  |  |
Land and Improvements |  | 56,853 |  |  |
Building and Improvements |  | 345,586 |  |  |
Total |  | 402,439 |  |  |
Accumulated Depreciation |  | $ 104,864 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 510 Madison Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 103,000 |  |  |
Original Building |  | 253,665 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 31,682 |  |  |
Land and Improvements |  | 103,000 |  |  |
Building and Improvements |  | 285,347 |  |  |
Total |  | 388,347 |  |  |
Accumulated Depreciation |  | $ 95,520 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 325 Main Street | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 21,596 |  |  |
Original Building |  | 312,492 |  |  |
Costs Capitalized Subsequent to Acquisition |  | (193) |  |  |
Land and Improvements |  | 21,403 |  |  |
Building and Improvements |  | 312,492 |  |  |
Total |  | 333,895 |  |  |
Accumulated Depreciation |  | $ 4,308 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 680 Folsom Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 72,545 |  |  |
Original Building |  | 219,766 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 8,026 |  |  |
Land and Improvements |  | 72,545 |  |  |
Building and Improvements |  | 227,792 |  |  |
Total |  | 300,337 |  |  |
Accumulated Depreciation |  | $ 72,414 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 145 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 121 |  |  |
Original Building |  | 273,013 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 25,981 |  |  |
Land and Improvements |  | 23,164 |  |  |
Building and Improvements |  | 275,951 |  |  |
Total |  | 299,115 |  |  |
Accumulated Depreciation |  | $ 26,881 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 2200 Pennsylvania Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 183,541 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 113,108 |  |  |
Land and Improvements |  | 104,329 |  |  |
Building and Improvements |  | 192,320 |  |  |
Total |  | 296,649 |  |  |
Accumulated Depreciation |  | $ 71,410 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | South of Market and Democracy Tower | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,603 |  |  |
Original Building |  | 237,479 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 28,655 |  |  |
Land and Improvements |  | 13,603 |  |  |
Building and Improvements |  | 266,134 |  |  |
Total |  | 279,737 |  |  |
Accumulated Depreciation |  | $ 98,574 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Bay Colony Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,789 |  |  |
Original Building |  | 148,451 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 87,804 |  |  |
Land and Improvements |  | 18,789 |  |  |
Building and Improvements |  | 231,828 |  |  |
Land held for development |  | 4,427 |  |  |
Total |  | 255,044 |  |  |
Accumulated Depreciation |  | $ 105,172 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 535 Mission Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 40,933 |  |  |
Original Building |  | 148,378 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,852 |  |  |
Land and Improvements |  | 40,934 |  |  |
Building and Improvements |  | 152,229 |  |  |
Total |  | 193,163 |  |  |
Accumulated Depreciation |  | $ 42,776 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Mountain View Research Park | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 95,066 |  |  |
Original Building |  | 68,373 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 21,270 |  |  |
Land and Improvements |  | 95,066 |  |  |
Building and Improvements |  | 89,643 |  |  |
Total |  | 184,709 |  |  |
Accumulated Depreciation |  | $ 28,575 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Reservoir Place | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,605 |  |  |
Original Building |  | 104,124 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 51,284 |  |  |
Land and Improvements |  | 19,089 |  |  |
Building and Improvements |  | 153,859 |  |  |
Land held for development |  | 1,065 |  |  |
Total |  | 174,013 |  |  |
Accumulated Depreciation |  | $ 84,089 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 1330 Connecticut Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 25,982 |  |  |
Original Building |  | 82,311 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 33,434 |  |  |
Land and Improvements |  | 25,982 |  |  |
Building and Improvements |  | 115,745 |  |  |
Total |  | 141,727 |  |  |
Accumulated Depreciation |  | $ 46,795 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | One Freedom Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 9,929 |  |  |
Original Building |  | 84,504 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 46,106 |  |  |
Land and Improvements |  | 9,883 |  |  |
Building and Improvements |  | 130,656 |  |  |
Total |  | 140,539 |  |  |
Accumulated Depreciation |  | $ 64,278 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 880 Winter Street [Member] | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 15,597 |  |  |
Original Building |  | 37,255 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 91,537 |  |  |
Land and Improvements |  | 15,597 |  |  |
Building and Improvements |  | 128,792 |  |  |
Total |  | 144,389 |  |  |
Accumulated Depreciation |  | $ 2,560 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Kingstowne Towne Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,021 |  |  |
Original Building |  | 109,038 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,658 |  |  |
Land and Improvements |  | 18,021 |  |  |
Building and Improvements |  | 112,696 |  |  |
Total |  | 130,717 |  |  |
Accumulated Depreciation |  | $ 52,498 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 140 Kendrick Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,095 |  |  |
Original Building |  | 66,905 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 38,538 |  |  |
Land and Improvements |  | 18,095 |  |  |
Building and Improvements |  | 99,632 |  |  |
Development and Construction in Progress |  | 5,811 |  |  |
Total |  | 123,538 |  |  |
Accumulated Depreciation |  | $ 40,368 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Shady Grove Innovation District [Member] | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 52,030 |  |  |
Original Building |  | 64,212 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 7,219 |  |  |
Land and Improvements |  | 26,834 |  |  |
Building and Improvements |  | 34,988 |  |  |
Land held for development |  | 61,639 |  |  |
Total |  | 123,461 |  |  |
Accumulated Depreciation |  | $ 3,319 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | One and Two Reston Overlook | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 16,456 |  |  |
Original Building |  | 66,192 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 36,098 |  |  |
Land and Improvements |  | 15,074 |  |  |
Building and Improvements |  | 103,672 |  |  |
Total |  | 118,746 |  |  |
Accumulated Depreciation |  | $ 56,216 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Weston Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 25,753 |  |  |
Original Building |  | 92,312 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 968 |  |  |
Land and Improvements |  | 25,854 |  |  |
Building and Improvements |  | 93,179 |  |  |
Total |  | 119,033 |  |  |
Accumulated Depreciation |  | $ 38,385 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 17Fifty Presidents Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 113,362 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 162 |  |  |
Land and Improvements |  | 0 |  |  |
Building and Improvements |  | 113,524 |  |  |
Total |  | 113,524 |  |  |
Accumulated Depreciation |  | $ 12,232 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Discovery Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 11,198 |  |  |
Original Building |  | 71,782 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 16,073 |  |  |
Land and Improvements |  | 11,146 |  |  |
Building and Improvements |  | 87,907 |  |  |
Total |  | 99,053 |  |  |
Accumulated Depreciation |  | $ 52,341 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 355 Main Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,863 |  |  |
Original Building |  | 53,346 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 25,120 |  |  |
Land and Improvements |  | 21,098 |  |  |
Building and Improvements |  | 76,231 |  |  |
Total |  | 97,329 |  |  |
Accumulated Depreciation |  | $ 34,306 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 10 CityPoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,953 |  |  |
Original Building |  | 85,752 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,243 |  |  |
Land and Improvements |  | 2,127 |  |  |
Building and Improvements |  | 91,821 |  |  |
Total |  | 93,948 |  |  |
Accumulated Depreciation |  | $ 20,616 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Two Freedom Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,930 |  |  |
Original Building |  | 77,739 |  |  |
Costs Capitalized Subsequent to Acquisition |  | (5,895) |  |  |
Land and Improvements |  | 13,866 |  |  |
Building and Improvements |  | 71,908 |  |  |
Total |  | 85,774 |  |  |
Accumulated Depreciation |  | $ 33,860 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 200 West Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 16,148 |  |  |
Original Building |  | 24,983 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 46,603 |  |  |
Land and Improvements |  | 16,148 |  |  |
Building and Improvements |  | 71,269 |  |  |
Land held for development |  | 317 |  |  |
Total |  | 87,734 |  |  |
Accumulated Depreciation |  | $ 22,576 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 90 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 19,104 |  |  |
Original Building |  | 52,078 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 18,697 |  |  |
Land and Improvements |  | 20,741 |  |  |
Building and Improvements |  | 69,138 |  |  |
Total |  | 89,879 |  |  |
Accumulated Depreciation |  | $ 29,243 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 153 & 211 Second Avenue [Member] | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 33,233 |  |  |
Original Building |  | 55,940 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 202 |  |  |
Land and Improvements |  | 33,233 |  |  |
Building and Improvements |  | 55,940 |  |  |
Land held for development |  | 202 |  |  |
Total |  | 89,375 |  |  |
Accumulated Depreciation |  | $ 4,808 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 230 CityPoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,189 |  |  |
Original Building |  | 49,823 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 22,987 |  |  |
Land and Improvements |  | 13,403 |  |  |
Building and Improvements |  | 72,596 |  |  |
Total |  | 85,999 |  |  |
Accumulated Depreciation |  | $ 37,791 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 20 Citypoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 4,887 |  |  |
Original Building |  | 72,764 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 7,072 |  |  |
Land and Improvements |  | 4,887 |  |  |
Building and Improvements |  | 79,836 |  |  |
Total |  | 84,723 |  |  |
Accumulated Depreciation |  | $ 9,606 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Waltham Weston Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 10,385 |  |  |
Original Building |  | 60,694 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 9,872 |  |  |
Land and Improvements |  | 10,350 |  |  |
Building and Improvements |  | 70,601 |  |  |
Total |  | 80,951 |  |  |
Accumulated Depreciation |  | $ 41,883 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 77 CityPoint | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,847 |  |  |
Original Building |  | 60,383 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 9,596 |  |  |
Land and Improvements |  | 13,997 |  |  |
Building and Improvements |  | 69,829 |  |  |
Total |  | 83,826 |  |  |
Accumulated Depreciation |  | $ 32,548 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Sumner Square | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 624 |  |  |
Original Building |  | 28,745 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 47,222 |  |  |
Land and Improvements |  | 27,685 |  |  |
Building and Improvements |  | 48,906 |  |  |
Total |  | 76,591 |  |  |
Accumulated Depreciation |  | $ 30,773 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 2440 West El Camino Real | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 16,741 |  |  |
Original Building |  | 51,285 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,391 |  |  |
Land and Improvements |  | 16,741 |  |  |
Building and Improvements |  | 57,676 |  |  |
Total |  | 74,417 |  |  |
Accumulated Depreciation |  | $ 19,375 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 300 Binney Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 18,080 |  |  |
Original Building |  | 51,262 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,268 |  |  |
Land and Improvements |  | 18,080 |  |  |
Building and Improvements |  | 51,402 |  |  |
Land held for development |  | 1,128 |  |  |
Total |  | 70,610 |  |  |
Accumulated Depreciation |  | $ 18,995 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Reston Corporate Center | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 9,135 |  |  |
Original Building |  | 50,857 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,968 |  |  |
Land and Improvements |  | 9,496 |  |  |
Building and Improvements |  | 53,464 |  |  |
Total |  | 62,960 |  |  |
Accumulated Depreciation |  | $ 32,986 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Wisconsin Place | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 53,349 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 11,204 |  |  |
Land and Improvements |  | 0 |  |  |
Building and Improvements |  | 64,553 |  |  |
Total |  | 64,553 |  |  |
Accumulated Depreciation |  | $ 26,659 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 255 Main Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 134 |  |  |
Original Building |  | 25,110 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 31,941 |  |  |
Land and Improvements |  | 134 |  |  |
Building and Improvements |  | 57,051 |  |  |
Total |  | 57,185 |  |  |
Accumulated Depreciation |  | $ 41,677 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | University Place | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 37,091 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 14,453 |  |  |
Land and Improvements |  | 5,425 |  |  |
Building and Improvements |  | 46,119 |  |  |
Total |  | 51,544 |  |  |
Accumulated Depreciation |  | $ 34,270 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 890 Winter Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 13,913 |  |  |
Original Building |  | 28,557 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,998 |  |  |
Land and Improvements |  | 13,913 |  |  |
Building and Improvements |  | 35,555 |  |  |
Total |  | 49,468 |  |  |
Accumulated Depreciation |  | $ 5,409 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Capital Gallery | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 4,725 |  |  |
Original Building |  | 29,565 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 4,882 |  |  |
Land and Improvements |  | 6,128 |  |  |
Building and Improvements |  | 33,044 |  |  |
Total |  | 39,172 |  |  |
Accumulated Depreciation |  | $ 21,506 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | North First Business Park | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 23,398 |  |  |
Original Building |  | 13,069 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,265 |  |  |
Land and Improvements |  | 23,372 |  |  |
Building and Improvements |  | 18,360 |  |  |
Total |  | 41,732 |  |  |
Accumulated Depreciation |  | $ 17,264 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 150 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 850 |  |  |
Original Building |  | 25,042 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 13,721 |  |  |
Land and Improvements |  | 822 |  |  |
Building and Improvements |  | 38,791 |  |  |
Total |  | 39,613 |  |  |
Accumulated Depreciation |  | $ 16,195 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 105 Broadway | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,299 |  |  |
Original Building |  | 12,943 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 10,611 |  |  |
Land and Improvements |  | 1,862 |  |  |
Building and Improvements |  | 22,991 |  |  |
Total |  | 24,853 |  |  |
Accumulated Depreciation |  | $ 14,898 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Lexington Office Park | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 998 |  |  |
Original Building |  | 1,426 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 19,078 |  |  |
Land and Improvements |  | 1,072 |  |  |
Building and Improvements |  | 18,978 |  |  |
Land held for development |  | 1,452 |  |  |
Total |  | 21,502 |  |  |
Accumulated Depreciation |  | $ 16,474 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | The Point | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 6,395 |  |  |
Original Building |  | 10,040 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 546 |  |  |
Land and Improvements |  | 6,492 |  |  |
Building and Improvements |  | 10,489 |  |  |
Total |  | 16,981 |  |  |
Accumulated Depreciation |  | $ 2,308 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 690 Folsom Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 3,219 |  |  |
Original Building |  | 11,038 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,877 |  |  |
Land and Improvements |  | 3,219 |  |  |
Building and Improvements |  | 12,915 |  |  |
Total |  | 16,134 |  |  |
Accumulated Depreciation |  | $ 3,838 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 33 Hayden Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 266 |  |  |
Original Building |  | 3,234 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 10,864 |  |  |
Land and Improvements |  | 266 |  |  |
Building and Improvements |  | 14,098 |  |  |
Total |  | 14,364 |  |  |
Accumulated Depreciation |  | $ 7,725 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | The Avant Retail | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,499 |  |  |
Original Building |  | 6,647 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,577 |  |  |
Land and Improvements |  | 1,499 |  |  |
Building and Improvements |  | 9,224 |  |  |
Total |  | 10,723 |  |  |
Accumulated Depreciation |  | $ 3,210 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 92-100 Hayden Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 594 |  |  |
Original Building |  | 6,748 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,568 |  |  |
Land and Improvements |  | 595 |  |  |
Building and Improvements |  | 8,315 |  |  |
Total |  | 8,910 |  |  |
Accumulated Depreciation |  | $ 7,273 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 32 Hartwell Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 168 |  |  |
Original Building |  | 1,943 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,358 |  |  |
Land and Improvements |  | 168 |  |  |
Building and Improvements |  | 8,301 |  |  |
Total |  | 8,469 |  |  |
Accumulated Depreciation |  | $ 2,915 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 250 Binney Street | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 110 |  |  |
Original Building |  | 4,483 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,939 |  |  |
Land and Improvements |  | 110 |  |  |
Building and Improvements |  | 7,422 |  |  |
Total |  | 7,532 |  |  |
Accumulated Depreciation |  | $ 6,769 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 453 Ravendale Drive | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 5,477 |  |  |
Original Building |  | 1,090 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 677 |  |  |
Land and Improvements |  | 5,477 |  |  |
Building and Improvements |  | 1,767 |  |  |
Total |  | 7,244 |  |  |
Accumulated Depreciation |  | $ 964 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 17 Hartwell Avenue | Office Building [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 26 |  |  |
Original Building |  | 150 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,907 |  |  |
Land and Improvements |  | 26 |  |  |
Building and Improvements |  | 6,057 |  |  |
Total |  | 6,083 |  |  |
Accumulated Depreciation |  | $ 3,479 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | The Skylyne | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 28,962 |  |  |
Original Building |  | 239,077 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,784 |  |  |
Land and Improvements |  | 28,962 |  |  |
Building and Improvements |  | 240,861 |  |  |
Total |  | 269,823 |  |  |
Accumulated Depreciation |  | $ 14,154 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Signature at Reston | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 27,076 |  |  |
Original Building |  | 190,580 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,667 |  |  |
Land and Improvements |  | 27,076 |  |  |
Building and Improvements |  | 192,247 |  |  |
Total |  | 219,323 |  |  |
Accumulated Depreciation |  | $ 23,353 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Proto Kendall Square | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 9,243 |  |  |
Original Building |  | 127,248 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,336 |  |  |
Land and Improvements |  | 9,245 |  |  |
Building and Improvements |  | 130,582 |  |  |
Total |  | 139,827 |  |  |
Accumulated Depreciation |  | $ 14,508 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | The Lofts at Atlantic Wharf | Residential Building |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 3,529 |  |  |
Original Building |  | 54,891 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 2,356 |  |  |
Land and Improvements |  | 3,529 |  |  |
Building and Improvements |  | 57,247 |  |  |
Total |  | 60,776 |  |  |
Accumulated Depreciation |  | $ 17,174 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Boston Cambridge Marriott | Hotel [Member] |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 478 |  |  |
Original Building |  | 37,918 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 29,946 |  |  |
Land and Improvements |  | 478 |  |  |
Building and Improvements |  | 67,353 |  |  |
Land held for development |  | 511 |  |  |
Total |  | 68,342 |  |  |
Accumulated Depreciation |  | $ 50,642 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Kendall Center Green Garage | Garage |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 35,035 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 6,384 |  |  |
Building and Improvements |  | 41,419 |  |  |
Total |  | 41,419 |  |  |
Accumulated Depreciation |  | $ 16,909 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Kendall Center Yellow Garage | Garage |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,256 |  |  |
Original Building |  | 15,697 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 941 |  |  |
Land and Improvements |  | 1,256 |  |  |
Building and Improvements |  | 16,638 |  |  |
Total |  | 17,894 |  |  |
Accumulated Depreciation |  | $ 7,170 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | Kendall Center Blue Garage | Garage |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 1,163 |  |  |
Original Building |  | 11,633 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 446 |  |  |
Land and Improvements |  | 1,163 |  |  |
Building and Improvements |  | 12,079 |  |  |
Total |  | 13,242 |  |  |
Accumulated Depreciation |  | $ 12,006 |  |  |
Depreciable Lives (Years) | [9] | (1) |  |  |
Boston Properties Limited Partnership | 2100 Pennsylvania Avenue | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 472,873 |  |  |
Land and Improvements |  | 185,203 |  |  |
Building and Improvements |  | 230,497 |  |  |
Development and Construction in Progress |  | 57,173 |  |  |
Total |  | 472,873 |  |  |
Accumulated Depreciation |  | $ 9,755 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | 190 CityPoint (formerly 180 CityPoint) [Member] | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 140,370 |  |  |
Development and Construction in Progress |  | 140,370 |  |  |
Total |  | 140,370 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | 103 CityPoint | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 44,752 |  |  |
Land held for development |  | 74 |  |  |
Development and Construction in Progress |  | 44,678 |  |  |
Total |  | 44,752 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Reston Next Office Phase II | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 22,954 |  |  |
Development and Construction in Progress |  | 22,954 |  |  |
Total |  | 22,954 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Reston Next Retail | Development |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,199 |  |  |
Development and Construction in Progress |  | 3,199 |  |  |
Total |  | 3,199 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | 777 Harrison Street | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 144,647 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 28,239 |  |  |
Building and Improvements |  | 47 |  |  |
Land held for development |  | 172,839 |  |  |
Total |  | 172,886 |  |  |
Accumulated Depreciation |  | $ 20 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Kendall Center Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 148,476 |  |  |
Land held for development |  | 148,476 |  |  |
Total |  | 148,476 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Back Bay Station Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 72,957 |  |  |
Land held for development |  | 72,957 |  |  |
Total |  | 72,957 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | 3625 - 3635 Peterson Way | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 63,206 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 5,165 |  |  |
Land held for development |  | 68,371 |  |  |
Total |  | 68,371 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | North First Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 35,004 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 3,968 |  |  |
Land held for development |  | 38,972 |  |  |
Total |  | 38,972 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Plaza at Almaden | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 38,090 |  |  |
Land held for development |  | 38,090 |  |  |
Total |  | 38,090 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Springfield Metro Center | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 19,891 |  |  |
Land held for development |  | 19,891 |  |  |
Total |  | 19,891 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | CityPoint South Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 19,693 |  |  |
Land held for development |  | 19,693 |  |  |
Total |  | 19,693 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Reston Gateway Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 12,734 |  |  |
Land held for development |  | 12,734 |  |  |
Total |  | 12,734 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Weston Quarry | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,249 |  |  |
Land held for development |  | 1,249 |  |  |
Total |  | 1,249 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Broad Run Business Park | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 1,184 |  |  |
Land held for development |  | 1,184 |  |  |
Total |  | 1,184 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
Boston Properties Limited Partnership | Reston Overlook Master Plan | Land |  |  |  |  |
Original Cost |  |  |  |  |
Original Land |  | $ 0 |  |  |
Original Building |  | 0 |  |  |
Costs Capitalized Subsequent to Acquisition |  | 80 |  |  |
Land held for development |  | 80 |  |  |
Total |  | 80 |  |  |
Accumulated Depreciation |  | $ 0 |  |  |
Depreciable Lives (Years) |  | N/A |  |  |
[1] | Includes unamortized deferred financing costs totaling approximately $27,632.
[2] | Includes Right of Use Assets - Finance Leases and Right of Use Assets - Operating Leases of approximately $214,165 and $167,351, respectively.
[3] | Includes Right of Use Assets - Finance Leases of approximately $23,345.
[4] | Includes pre-development costs.
[5] | Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years.
[6] | Includes unamortized deferred financing costs totaling approximately $27,632.
[7] | Includes Right of Use Assets - Finance Leases and Right of Use Assets - Operating Leases of approximately $214,165 and $167,351, respectively.
[8] | Includes Right of Use Assets - Finance Leases of approximately $23,345.
[9] | Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years.

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