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Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	$ 108,297,000	$ 89,854,000	$ 311,680,000	$ 854,541,000
Preferred Stock Redemption Charge	0	0	(6,412,000)	0
Preferred dividends / distributions	0	(2,625,000)	(2,560,000)	(7,875,000)
Noncontrolling interest-common units of the Operating Partnership	(11,982,000)	(10,020,000)	(35,393,000)	(97,090,000)
Noncontrolling interest in property partnerships	(18,971,000)	(15,561,000)	(52,602,000)	(34,280,000)
Interest expense	(105,794,000)	(110,993,000)	(320,015,000)	(319,726,000)
Loss from early extinguishment of debt	0	0	898,000	0
Income (loss) from unconsolidated joint ventures	5,597,000	6,873,000	1,745,000	5,410,000
Company's share of net operating income from joint ventures	(458,729,000)	(421,666,000)	(1,355,845,000)	(1,295,723,000)
Depreciation and amortization expense	(179,412,000)	(166,456,000)	(539,815,000)	(515,738,000)
Transaction costs	(1,888,000)	(307,000)	(2,970,000)	(1,254,000)
General and administrative expense	(34,560,000)	(27,862,000)	(117,924,000)	(102,059,000)
Gains (losses) from investments in securities	190,000	(1,858,000)	(3,744,000)	(965,000)
Interest and other income (loss)	(1,520,000)	45,000	(4,140,000)	(4,277,000)
Gains on sales of real estate	(348,000)	209,000	(8,104,000)	(613,723,000)
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	108,297,000	89,854,000	311,680,000	854,541,000
Preferred Stock Redemption Charge	0	0	6,412,000	0
Preferred dividends / distributions	0	2,625,000	2,560,000	7,875,000
Noncontrolling interest-common units of the Operating Partnership	11,982,000	10,020,000	35,393,000	97,090,000
Noncontrolling interest in property partnerships	18,971,000	15,561,000	52,602,000	34,280,000
Interest expense	105,794,000	110,993,000	320,015,000	319,726,000
Loss from early extinguishment of debt	0	0	898,000	0
Depreciation and amortization expense	179,412,000	166,456,000	539,815,000	515,738,000
Transaction costs	1,888,000	307,000	2,970,000	1,254,000
Operating expense	3,006,000	2,896,000	9,166,000	8,617,000
General and administrative expense	34,560,000	27,862,000	117,924,000	102,059,000
Gains (losses) from investments in securities	(190,000)	1,858,000	3,744,000	965,000
Interest and other income (loss)	1,520,000	(45,000)	4,140,000	4,277,000
Gains on sales of real estate	348,000	(209,000)	8,104,000	613,723,000
Other revenue	3,006,000	2,896,000	9,166,000	8,617,000
Company's share of Net Operating Income	435,195,000	404,444,000	1,291,860,000	1,255,082,000
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(27,519,000)	(25,481,000)	(78,711,000)	(71,370,000)
Income (loss) from unconsolidated joint ventures	5,597,000	6,873,000	1,745,000	5,410,000
Depreciation and amortization expense	(36,036,000)	(35,810,000)	(103,766,000)	(105,235,000)
Transaction costs	0	0	(7,000)	0
Gains on sales of real estate	0	0	0	(11,720,000)
Unconsolidated Joint Ventures [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	24,266,000	24,938,000	74,478,000	81,607,000
Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	122,014,000	101,624,000	353,633,000	969,932,000
Preferred Stock Redemption Charge	0	0	(6,412,000)	0
Preferred dividends / distributions	0	(2,625,000)	(2,560,000)	(7,875,000)
Noncontrolling interest in property partnerships	(18,971,000)	(15,561,000)	(52,602,000)	(34,280,000)
Interest expense	(105,794,000)	(110,993,000)	(320,015,000)	(319,726,000)
Loss from early extinguishment of debt	0	0	898,000	0
Income (loss) from unconsolidated joint ventures	5,597,000	6,873,000	1,745,000	5,410,000
Depreciation and amortization expense	(177,677,000)	(164,706,000)	(533,255,000)	(510,400,000)
Transaction costs	(1,888,000)	(307,000)	(2,970,000)	(1,254,000)
General and administrative expense	(34,560,000)	(27,862,000)	(117,924,000)	(102,059,000)
Gains (losses) from investments in securities	190,000	(1,858,000)	(3,744,000)	(965,000)
Interest and other income (loss)	(1,520,000)	45,000	(4,140,000)	(4,277,000)
Gains on sales of real estate	(348,000)	209,000	(8,104,000)	(626,686,000)
Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	122,014,000	101,624,000	353,633,000	969,932,000
Preferred Stock Redemption Charge	0	0	6,412,000	0
Preferred dividends / distributions	0	2,625,000	2,560,000	7,875,000
Noncontrolling interest in property partnerships	18,971,000	15,561,000	52,602,000	34,280,000
Interest expense	105,794,000	110,993,000	320,015,000	319,726,000
Loss from early extinguishment of debt	0	0	898,000	0
Income (loss) from unconsolidated joint ventures	5,597,000	6,873,000	1,745,000	5,410,000
Depreciation and amortization expense	177,677,000	164,706,000	533,255,000	510,400,000
Transaction costs	1,888,000	307,000	2,970,000	1,254,000
Operating expense	3,006,000	2,896,000	9,166,000	8,617,000
General and administrative expense	34,560,000	27,862,000	117,924,000	102,059,000
Gains (losses) from investments in securities	(190,000)	1,858,000	3,744,000	965,000
Interest and other income (loss)	1,520,000	(45,000)	4,140,000	4,277,000
Gains on sales of real estate	348,000	(209,000)	8,104,000	626,686,000
Other revenue	3,006,000	2,896,000	9,166,000	8,617,000
Company's share of Net Operating Income	435,195,000	404,444,000	1,291,860,000	1,255,082,000
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(6,094,000)	(7,281,000)	(20,181,000)	(23,285,000)
Management Service [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	6,094,000	7,281,000	20,181,000	23,285,000
Management Service [Member] | Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(6,094,000)	(7,281,000)	(20,181,000)	(23,285,000)
Management Service [Member] | Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	6,094,000	7,281,000	20,181,000	23,285,000
Noncontrolling interest - property partnerships [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	47,800,000	42,160,000	138,463,000	122,248,000
Noncontrolling interest - property partnerships [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	47,800,000	42,160,000	138,463,000	122,248,000
Noncontrolling interest - property partnerships [Member] | Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	$ 47,800,000	$ 42,160,000	$ 138,463,000	$ 122,248,000

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