Consolidated Statement of Capital and Noncontrolling Interests - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Common Stock, Shares, Outstanding	156,206,491		156,206,491			155,718,825
Effective portion of interest rate contracts	$ 1,088	$ 1,027	$ 5,482	$ (9,352)
Amortization of interest rate contracts	1,676	1,677	5,028	5,020
Contributions from noncontrolling interests in property partnerships	11,318	1,407	13,738	7,364
Distributions to noncontrolling interests in property partnerships	(27,675)	(11,026)	(65,604)	(40,091)
Preferred Stock Redemption Charge	0	0	(6,412)	0
Net activity from stock option and incentive plan, value	$ 8,864	$ 8,639	$ 60,228	$ 41,924
Accounting Standards Update 2018-09
Accounting Standards Update [Extensible List]				Accounting Standards Update 2018-09
General Partner [Member]
Common Stock, Shares, Outstanding	1,737,000	1,731,000	1,737,000	1,731,000	1,737,000	1,731,000	1,731,000	1,727,000
Net activity from stock option and incentive plan, shares			4,000	1,000
Conversion of redeemable partnership units			2,000	3,000
Limited Partner [Member]
Common Stock, Shares, Outstanding	154,470,000	153,905,000	154,470,000	153,905,000	154,399,000	153,988,000	153,891,000	153,063,000
Net activity from stock option and incentive plan, shares	21,000	5,000	255,000	73,000
Conversion of redeemable partnership units	50,000	9,000	227,000	769,000
Partners' Capital (General and Limited Partners)[Member]
Beginning Balance	$ 4,209,117	$ 4,943,849	$ 4,209,117	$ 4,943,849	$ 4,132,880	$ 4,554,639	$ 4,828,066	$ 3,380,175
Contributions, value	1,705	1,824	21,900	10,405
Allocated net income for the period	110,043	92,059	324,652	872,842
Distributions	(153,082)	(152,518)	(459,048)	(457,233)
Conversion of redeemable partnership units, value	1,748	338	8,033	26,682
Adjustment to reflect redeemable partnership units at redemption value	115,823	174,080	(234,647)	1,112,483
Preferred Stock Redemption Charge			(6,412)
Partners' Capital (General and Limited Partners)[Member] | Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance								(1,505)
Preferred Units [Member]
Beginning Balance	0	193,623	0	193,623	0	193,623	193,623	193,623
Allocated net income for the period		2,625	2,560	7,875
Distributions		(2,625)	(2,560)	(7,875)
Preferred Units [Member] | Boston Properties Limited Partnership
Preferred Stock, Redemption Amount	(193,623)		(193,623)
Accumulated Other Comprehensive Loss [Member]
Beginning Balance	(40,803)	(52,622)	(40,803)	(52,622)	(43,166)	(49,890)	(54,921)	(48,335)
Effective portion of interest rate contracts	981	917	4,943	(8,416)
Amortization of interest rate contracts	1,382	1,382	4,144	4,129
Noncontrolling interest - property partnerships [Member]
Beginning Balance	1,728,101	1,730,674	1,728,101	1,730,674	1,725,343	1,726,933	1,724,588	1,728,689
Allocated net income for the period	18,971	15,561	52,602	34,280
Amortization of interest rate contracts	144	144	432	432
Contributions from noncontrolling interests in property partnerships	11,318	1,407	13,738	7,364
Distributions to noncontrolling interests in property partnerships	(27,675)	(11,026)	(65,604)	(40,091)
Total Capital [Member]
Beginning Balance	5,896,415	6,815,524	5,896,415	6,815,524	5,815,057	6,425,305	6,691,356	5,254,152
Contributions, value	1,705	1,824	21,900	10,405
Allocated net income for the period	129,014	110,245	379,814	914,997
Distributions	(153,082)	(155,143)	(461,608)	(465,108)
Conversion of redeemable partnership units, value	1,748	338	8,033	26,682
Adjustment to reflect redeemable partnership units at redemption value	115,823	174,080	(234,647)	1,112,483
Effective portion of interest rate contracts	981	917	4,943	(8,416)
Amortization of interest rate contracts	1,526	1,526	4,576	4,561
Contributions from noncontrolling interests in property partnerships	11,318	1,407	13,738	7,364
Distributions to noncontrolling interests in property partnerships	(27,675)	(11,026)	(65,604)	(40,091)
Preferred Stock, Redemption Amount	(193,623)		(193,623)
Preferred Stock Redemption Charge			(6,412)
Total Capital [Member] | Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance								(1,505)
Noncontrolling interest - Redeemable partnership units [Member]
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount	1,893,611	1,406,484	1,893,611	1,406,484	$ 2,008,478	$ 1,643,024	$ 1,581,010	2,468,753
Contributions, value	7,679		39,332	32,278
Allocated net income for the period	11,971	9,565	35,393	97,090
Distributions	(17,203)	(17,183)	(51,743)	(51,821)
Conversion of redeemable partnership units, value	(1,748)	(338)	(8,033)	(26,682)
Adjustment to reflect redeemable partnership units at redemption value	(115,823)	(174,080)	234,647	(1,112,483)
Effective portion of interest rate contracts	107	110	539	(936)
Amortization of interest rate contracts	150	151	452	459
Contributions from noncontrolling interests in property partnerships	0	0	0	0
Distributions to noncontrolling interests in property partnerships	0	0	0	$ 0
Preferred Stock, Redemption Amount	$ 0		0
Preferred Stock Redemption Charge			0
Net activity from stock option and incentive plan, value		$ 7,249
Noncontrolling interest - Redeemable partnership units [Member] | Cumulative Effect, Period of Adoption, Adjustment
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount								$ (174)
Dividends In Excess Of Earnings [Member]
Preferred Stock Redemption Charge			$ (6,412)