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Leases Narrative (Details) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 USD ($) | Sep. 30, 2019 USD ($) | Sep. 30, 2018 USD ($) | Jan. 01, 2019 USD ($)
Finance leases under development | 3 | 3 |  |
Cumulative effect of a change in accounting principle |  | $ 4,379,000 | $ (5,496,000) |
Right of use assets - operating leases | $ 149,231,000 | 149,231,000 |  | $ 151,800,000
Lease liabilities - operating leases | $ 199,755,000 | 199,755,000 |  | $ 199,300,000
Lessee, Finance Lease, Description | four |  |  |
Boston Properties Limited Partnership |  |  |  |
Right of use assets - operating leases | $ 149,231,000 | 149,231,000 |  |
Lease liabilities - operating leases | 199,755,000 | 199,755,000 |  |
Dividends In Excess Of Earnings [Member] |  |  |  |
Cumulative effect of a change in accounting principle |  | 3,864,000 | (4,933,000) |
Dividends In Excess Of Earnings [Member] | Boston Properties Limited Partnership |  |  |  |
Cumulative effect of a change in accounting principle |  | 3,900,000 |  |
Noncontrolling Interests - Common units [Member] |  |  |  |
Cumulative effect of a change in accounting principle |  | 445,000 | $ (563,000) |
Noncontrolling Interests - Common units [Member] | Boston Properties Limited Partnership |  |  |  |
Cumulative effect of a change in accounting principle |  | 400,000 |  |
Noncontrolling interest - property partnerships [Member] |  |  |  |
Cumulative effect of a change in accounting principle | $ 0 | 70,000 |  |
Noncontrolling interest - property partnerships [Member] | Boston Properties Limited Partnership |  |  |  |
Cumulative effect of a change in accounting principle |  | $ 70,000 |  |

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