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Subsequent Events (Details) $ in Thousands |  |  |  |  |  |  |  | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Apr. 01, 2019 USD ($) | Feb. 14, 2019 ft² yr | Feb. 09, 2019 USD ($) shares | Feb. 05, 2019 USD ($) shares | Jan. 24, 2019 USD ($) ft² a yr | Nov. 29, 2018 ft² a yr | Nov. 16, 2018 USD ($) ft² yr | Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 USD ($) shares | Dec. 31, 2016 USD ($) | Feb. 01, 2019 shares | Jan. 10, 2019 USD ($) ft² | Dec. 01, 2018 ft² | May 23, 2018 shares
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Noncontrolling Interests |  |  |  |  |  |  |  | $ 82,501 | $ 54,342 | $ 55,474 |  |  |  |
Common stock, shares issued | shares |  |  |  |  |  |  |  | 154,537,378 | 154,404,186 |  |  |  |  | 36,836
Subsequent Event [Member] | MYLTIPS 2019 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Value of MYLTIP Awards |  |  |  | $ 13,500 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIPS 2019 [Member] | NAREIT Office Index adjusted [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Target Tier | shares |  |  |  | 110,367.00 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | MYLTIP 2016 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Value of MYLTIP Awards |  |  | $ 13,600 |  |  |  |  |  |  |  |  |  |  |
Final awards percentage of target |  |  | 69.50% |  |  |  |  |  |  |  |  |  |  |
MYLTIP Units forfeited | shares |  |  | 364,980 |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Minimum [Member] | MYLTIPS 2019 [Member] | NAREIT Office Index adjusted [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum earned awards | shares |  |  |  | 0 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Maximum [Member] | MYLTIPS 2019 [Member] | NAREIT Office Index adjusted [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
maximum earned awards | shares |  |  |  | 220,734 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Restricted Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares issued | shares |  |  |  |  |  |  |  |  |  |  | 23,083 |  |  |
Subsequent Event [Member] | LTIP Units [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
LTIP units issued (in shares) | shares |  |  |  | 172,166 |  |  |  |  |  |  |  |  |  |
Boston Properties Limited Partnership |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Noncontrolling Interests |  |  |  |  |  |  |  | $ 82,501 | $ 54,342 | $ 55,474 |  |  |  |
Salesforce Tower |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  |  |  |  |  |  |  |  |  | 1,421,000 |
Salesforce Tower | Salesforce Tower | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage | 5.00% |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Noncontrolling Interests | $ 210,900 |  |  |  |  |  |  |  |  |  |  |  |  |
Repayment preferred equity | $ 24,100 |  |  |  |  |  |  |  |  |  |  |  |  |
Platform 16 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  |  | 1,100,000 |  |  |  |  |  |  |  |
Ground Lease Term (in years) | yr |  |  |  |  |  | 65 |  |  |  |  |  |  |  |
Area of Land | a |  |  |  |  |  | 5.6 |  |  |  |  |  |  |  |
Platform 16 | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ground Lease Term (in years) | yr |  |  |  |  | 65 |  |  |  |  |  |  |  |  |
Area of Land | a |  |  |  |  | 5.6 |  |  |  |  |  |  |  |  |
325 Main Street | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  | 115,000 |  |  |  |  |  |  |  |  |  |  |  |
Term of Lease Signed (in years) | yr |  | 15 |  |  |  |  |  |  |  |  |  |  |  |
Square Footage Of Signed Lease | ft² |  | 362,000 |  |  |  |  |  |  |  |  |  |  |  |
Future office building [Member] | 325 Main Street | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  | 400,000 |  |  |  |  |  |  |  |  |  |  |  |
Future retail building [Member] | 325 Main Street | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  | 38,000 |  |  |  |  |  |  |  |  |  |  |  |
2600 Tower Oaks Boulevard | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contractual Sales Price |  |  |  |  | $ 22,700 |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  | 179,000 |  |  |  |  |  |  |  |  |
Annapolis Junction Building Six [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  |  |  | 119,000 |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  |  |  | 50.00% |  |  |  |  |  |  |
Construction Loan |  |  |  |  |  |  | $ 13,100 |  |  |  |  |  |  |
Number of extensions |  |  |  |  |  |  | 1 |  |  |  |  |  |  |
Extension Option (in years) | yr |  |  |  |  |  |  | 1 |  |  |  |  |  |  |
Construction Loan Facility Borrowing Capacity |  |  |  |  |  |  | $ 14,300 |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  | 2.00% |  |  |  |  |  |  |
Annapolis Junction Building Six [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Rentable Area | ft² |  |  |  |  | 119,000 |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  | 50.00% |  |  |  |  |  |  |  |  |
Construction Loan |  |  |  |  | $ 13,000 |  |  |  |  |  |  |  |  |
Number of extensions |  |  |  |  | 1 |  |  |  |  |  |  |  |  |
Extension Option (in years) | yr |  |  |  |  | 1 |  |  |  |  |  |  |  |  |
Construction Loan Facility Borrowing Capacity |  |  |  |  | $ 14,300 |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  | 2.00% |  |  |  |  |  |  |  |  |
Carnegie Center | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate purchase price |  |  |  |  |  |  |  |  |  |  |  | $ 42,900 |  |
Deferred purchase price |  |  |  |  |  |  |  |  |  |  |  | $ 8,600 |  |
Net Rentable Area | ft² |  |  |  |  |  |  |  |  |  |  |  | 1,700,000.0 |  |

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