Consolidated Statement of Capital and Noncontrolling Interests Statement - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Common Stock, Shares, Outstanding	155,314,555		154,790,298
Cumulative effect of a change in accounting principle	$ (1,679)	$ (4,379)
Effective portion of interest rate contracts	(9,720)	(2,628)
Amortization of interest rate contracts	1,666	1,666
Contributions from noncontrolling interests in property partnerships	3,876	4,387
Distributions to noncontrolling interests in property partnerships	$ (15,750)	$ (24,128)
General Partner [Member]
Common Stock, Shares, Outstanding	1,731,000	1,725,000	1,727,000	1,722,000
Contributions, units	1,000	2,000
Conversion of redeemable partnership units	3,000	1,000
Limited Partner [Member]
Common Stock, Shares, Outstanding	153,584,000	152,790,000	153,063,000	152,736,000
Contributions, units	63,000	41,000
Conversion of redeemable partnership units	458,000	13,000
Boston Properties Limited Partnership
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount	$ 1,639,855		$ 2,468,753
Contributions from noncontrolling interests in property partnerships	3,876	$ 4,387
Partners' Capital (General and Limited Partners) [Member]
Beginning Balance	4,626,627	3,603,174	3,380,175	$ 4,054,996
Cumulative effect of a change in accounting principle	(1,505)	(3,864)
Contributions, value	6,712	4,820
Allocated net income for the period	508,794	101,783
Distributions	(152,208)	(146,790)
Unearned compensation	996	(1,388)
Conversion of redeemable partnership units, value	15,495	492
Adjustment to reflect redeemable partnership units at redemption value	868,168	(406,875)
Preferred Units [Member]
Beginning Balance	193,623	193,623	193,623	193,623
Allocated net income for the period	2,625	2,625
Distributions	(2,625)	(2,625)
Accumulated Other Comprehensive Loss [Member]
Beginning Balance	(55,700)	(48,734)	(48,335)	(47,741)
Effective portion of interest rate contracts	(8,732)	(2,359)
Amortization of interest rate contracts	1,367	1,366
Noncontrolling interest - property partnerships [Member]
Beginning Balance	1,736,445	1,710,608	1,728,689	1,711,445
Cumulative effect of a change in accounting principle	0	(70)
Allocated net income for the period	19,486	18,830
Effective portion of interest rate contracts	0	0
Amortization of interest rate contracts	144	144
Contributions from noncontrolling interests in property partnerships	3,876	4,387
Distributions to noncontrolling interests in property partnerships	(15,750)	(24,128)
Total Capital [Member]
Beginning Balance	6,500,995	5,458,671	5,254,152	5,912,323
Cumulative effect of a change in accounting principle	(1,505)	(3,934)
Contributions, value	6,712	4,820
Allocated net income for the period	530,905	123,238
Distributions	(154,833)	(149,415)
Unearned compensation	996	(1,388)
Conversion of redeemable partnership units, value	15,495	492
Adjustment to reflect redeemable partnership units at redemption value	868,168	(406,875)
Effective portion of interest rate contracts	(8,732)	(2,359)
Amortization of interest rate contracts	1,511	1,510
Contributions from noncontrolling interests in property partnerships	3,876	4,387
Distributions to noncontrolling interests in property partnerships	(15,750)	(24,128)
Noncontrolling interest - Redeemable partnership units [Member]
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount	1,639,855	2,414,240	$ 2,468,753	$ 2,000,591
Cumulative effect of a change in accounting principle	(174)	(445)
Contributions, value	39,741	34,400
Allocated net income for the period	57,539	11,599
Distributions	(17,444)	(17,185)
Unearned compensation	(24,064)	(20,990)
Conversion of redeemable partnership units, value	(15,495)	(492)
Adjustment to reflect redeemable partnership units at redemption value	(868,168)	406,875
Effective portion of interest rate contracts	(988)	(269)
Amortization of interest rate contracts	$ 155	$ 156

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