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Schedule III - Real Estate and Accumulated Depreciation (Details) $ in Thousands | Dec. 31, 2023 USD ($) ft² | Dec. 31, 2022 USD ($) ft² | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($)
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SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | $ 1,497,386 |  |  |
Initial Cost |  |  |  |
Land | 1,210,669 |  |  |
Building & Improvements | 4,495,893 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | (117,996) |  |  |
Building & Improvements | 1,467,536 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 1,092,671 |  |  |
Building & Improvements (3) | 5,963,429 |  |  |
Total | 7,056,100 | $ 9,198,799 | $ 7,650,907 | $ 7,355,079
Accumulated Depreciation | $ 2,035,311 | $ 2,039,554 | $ 1,896,199 | $ 1,956,077
Approximate Square Feet | ft² | 29,695,841 |  |  |
885 Third Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | $ 0 |  |  |
Initial Cost |  |  |  |
Land | 138,444 |  |  |
Building & Improvements | 244,040 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | (138,444) |  |  |
Building & Improvements | (125,747) |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 0 |  |  |
Building & Improvements (3) | 118,293 |  |  |
Total | 118,293 |  |  |
Accumulated Depreciation | 11,040 |  |  |
Approximate Square Feet | ft² |  | 218,796 |  |
420 Lexington Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 277,238 |  |  |
Initial Cost |  |  |  |
Land | 0 |  |  |
Building & Improvements | 333,499 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 242,766 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 0 |  |  |
Building & Improvements (3) | 576,265 |  |  |
Total | 576,265 |  |  |
Accumulated Depreciation | 227,258 |  |  |
711 Third Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 19,844 |  |  |
Building & Improvements | 115,769 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 72,821 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 19,844 |  |  |
Building & Improvements (3) | 188,590 |  |  |
Total | 208,434 |  |  |
Accumulated Depreciation | 91,897 |  |  |
555 West 57th Street |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 18,846 |  |  |
Building & Improvements | 140,946 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 12,521 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 18,846 |  |  |
Building & Improvements (3) | 153,467 |  |  |
Total | 172,313 |  |  |
Accumulated Depreciation | 98,508 |  |  |
461 Fifth Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 0 |  |  |
Building & Improvements | 88,276 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 28,873 |  |  |
Building & Improvements | 12,680 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 28,873 |  |  |
Building & Improvements (3) | 100,956 |  |  |
Total | 129,829 |  |  |
Accumulated Depreciation | 45,700 |  |  |
750 Third Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 51,093 |  |  |
Building & Improvements | 251,523 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 83,936 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 51,093 |  |  |
Building & Improvements (3) | 335,459 |  |  |
Total | 386,552 |  |  |
Accumulated Depreciation | 112,937 |  |  |
485 Lexington Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 450,000 |  |  |
Initial Cost |  |  |  |
Land | 78,282 |  |  |
Building & Improvements | 452,631 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | (15,086) |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 78,282 |  |  |
Building & Improvements (3) | 437,545 |  |  |
Total | 515,827 |  |  |
Accumulated Depreciation | 201,735 |  |  |
810 Seventh Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 114,077 |  |  |
Building & Improvements | 550,819 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 5,406 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 114,077 |  |  |
Building & Improvements (3) | 556,225 |  |  |
Total | 670,302 |  |  |
Accumulated Depreciation | 238,462 |  |  |
1185 Avenue of the Americas |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 0 |  |  |
Building & Improvements | 791,106 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 139,416 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 0 |  |  |
Building & Improvements (3) | 930,522 |  |  |
Total | 930,522 |  |  |
Accumulated Depreciation | 404,093 |  |  |
1350 Avenue of the Americas |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 90,941 |  |  |
Building & Improvements | 431,517 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 14,566 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 90,941 |  |  |
Building & Improvements (3) | 446,083 |  |  |
Total | 537,024 |  |  |
Accumulated Depreciation | 196,985 |  |  |
1-6 Landmark Square |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 100,000 |  |  |
Initial Cost |  |  |  |
Land | 27,852 |  |  |
Building & Improvements | 161,343 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | (6,939) |  |  |
Building & Improvements | (23,245) |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 20,913 |  |  |
Building & Improvements (3) | 138,098 |  |  |
Total | 159,011 |  |  |
Accumulated Depreciation | 46,789 |  |  |
7 Landmark Square |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 1,721 |  |  |
Building & Improvements | 8,417 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | (1,338) |  |  |
Building & Improvements | (6,240) |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 383 |  |  |
Building & Improvements (3) | 2,177 |  |  |
Total | 2,560 |  |  |
Accumulated Depreciation | 695 |  |  |
100 Church Street |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 370,000 |  |  |
Initial Cost |  |  |  |
Land | 34,994 |  |  |
Building & Improvements | 183,932 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 11,060 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 34,994 |  |  |
Building & Improvements (3) | 194,992 |  |  |
Total | 229,986 |  |  |
Accumulated Depreciation | 78,305 |  |  |
125 Park Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 120,900 |  |  |
Building & Improvements | 270,598 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 23,312 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 120,900 |  |  |
Building & Improvements (3) | 293,910 |  |  |
Total | 414,810 |  |  |
Accumulated Depreciation | 129,990 |  |  |
19 East 65th Street |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 8,603 |  |  |
Building & Improvements | 2,074 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 3,345 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 8,603 |  |  |
Building & Improvements (3) | 5,419 |  |  |
Total | 14,022 |  |  |
Accumulated Depreciation | 7 |  |  |
304 Park Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 54,489 |  |  |
Building & Improvements | 90,643 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 9,096 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 54,489 |  |  |
Building & Improvements (3) | 99,739 |  |  |
Total | 154,228 |  |  |
Accumulated Depreciation | 33,134 |  |  |
752-760 Madison Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 284,286 |  |  |
Building & Improvements | 8,314 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | (2,450) |  |  |
Building & Improvements | 187,847 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 281,836 |  |  |
Building & Improvements (3) | 196,161 |  |  |
Total | 477,997 |  |  |
Accumulated Depreciation | 4,991 |  |  |
719 Seventh Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 50,000 |  |  |
Initial Cost |  |  |  |
Land | 41,180 |  |  |
Building & Improvements | 46,232 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | (4,720) |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 41,180 |  |  |
Building & Improvements (3) | 41,512 |  |  |
Total | 82,692 |  |  |
Accumulated Depreciation | 5,986 |  |  |
110 Greene Street |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 45,120 |  |  |
Building & Improvements | 228,393 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 4,578 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 45,120 |  |  |
Building & Improvements (3) | 232,971 |  |  |
Total | 278,091 |  |  |
Accumulated Depreciation | 57,067 |  |  |
185 Broadway |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 190,148 |  |  |
Initial Cost |  |  |  |
Land | 45,540 |  |  |
Building & Improvements | 27,865 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 207,635 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 45,540 |  |  |
Building & Improvements (3) | 235,500 |  |  |
Total | 281,040 |  |  |
Accumulated Depreciation | 12,200 |  |  |
690 Madison Avenue |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 60,000 |  |  |
Initial Cost |  |  |  |
Land | 13,820 |  |  |
Building & Improvements | 51,732 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 0 |  |  |
Building & Improvements | 28 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 13,820 |  |  |
Building & Improvements (3) | 51,760 |  |  |
Total | 65,580 |  |  |
Accumulated Depreciation | 3,863 |  |  |
Other |  |  |  |
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] |  |  |  |
Encumbrances | 0 |  |  |
Initial Cost |  |  |  |
Land | 20,635 |  |  |
Building & Improvements | 16,224 |  |  |
Cost Capitalized Subsequent To Acquisition |  |  |  |
Land | 2,302 |  |  |
Building & Improvements | 611,561 |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Land | 22,937 |  |  |
Building & Improvements (3) | 627,785 |  |  |
Total | 650,722 |  |  |
Accumulated Depreciation | $ 33,669 |  |  |
885 Third Avenue |  |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Approximate Square Feet | ft² |  | 414,317 |  |
719 Seventh Avenue | 719 Seventh Avenue |  |  |  |
Gross Amount at Which Carried at Close of Period |  |  |  |
Interest in property (as a percent) | 75.00% |  |  |

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