Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	$ 496,223,000	$ 862,227,000		$ 511,034,000
Preferred Stock Redemption Charge	(6,412,000)	0		0
Preferred dividends / distributions	(2,560,000)	(10,500,000)		(10,500,000)
Noncontrolling interest-common units of the Operating Partnership	(55,931,000)	(97,704,000)		(59,345,000)
Noncontrolling interest in property partnerships	(70,806,000)	(48,260,000)		(71,120,000)
Interest expense	(423,346,000)	(431,717,000)		(412,717,000)
Loss from early extinguishment of debt	45,182,000	0		29,540,000
Company's share of net operating income from joint ventures	(1,814,288,000)	(1,694,075,000)		(1,826,123,000)
Depreciation and amortization expense	(717,336,000)	(683,751,000)		(677,764,000)
Transaction costs	(5,036,000)	(1,531,000)		(1,984,000)
General and administrative expense	(151,573,000)	(133,112,000)		(140,777,000)
Gains (losses) from investments in securities	(5,626,000)	(5,261,000)		(6,417,000)
Interest and other income (loss)	(5,704,000)	(5,953,000)		(18,939,000)
Gains on sales of real estate	(123,660,000)	(618,982,000)		(709,000)
Income (loss) from unconsolidated joint ventures	2,570,000	85,110,000		(46,592,000)
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	496,223,000	862,227,000		511,034,000
Preferred Stock Redemption Charge	6,412,000	0		0
Preferred dividends / distributions	2,560,000	10,500,000		10,500,000
Noncontrolling interest-common units of the Operating Partnership	55,931,000	97,704,000		59,345,000
Noncontrolling interest in property partnerships	70,806,000	48,260,000		71,120,000
Interest expense	423,346,000	431,717,000		412,717,000
Loss from early extinguishment of debt	45,182,000	0		29,540,000
Impairment loss	0	0		24,038,000
Depreciation and amortization expense	717,336,000	683,751,000		677,764,000
Transaction costs	5,036,000	1,531,000		1,984,000
Operating expense	12,487,000	11,626,000		10,386,000
General and administrative expense	151,573,000	133,112,000		140,777,000
Gains (losses) from investments in securities	5,626,000	5,261,000		6,417,000
Interest and other income (loss)	5,704,000	5,953,000		18,939,000
Gains on sales of real estate	123,660,000	618,982,000		709,000
Income (loss) from unconsolidated joint ventures	2,570,000	85,110,000		(46,592,000)
Other revenue	12,487,000	11,626,000		10,386,000
Company's share of Net Operating Income	1,735,740,000	1,626,131,000		1,739,850,000
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(108,884,000)	(98,051,000)		(84,409,000)
Depreciation and amortization expense	(147,121,000)	(141,853,000)		(102,296,000)
Transaction costs	(470,000)	(1,027,000)		(1,000,000)
Gains on sales of real estate	0	(11,737,000)	[1]	(32,706,000)	[1]
Income (loss) from unconsolidated joint ventures	2,570,000	85,110,000		(46,592,000)
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	107,756,000	94,943,000		97,716,000
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	561,993,000	979,979,000		580,102,000
Preferred Stock Redemption Charge	(6,412,000)	0		0
Preferred dividends / distributions	(2,560,000)	(10,500,000)		(10,500,000)
Noncontrolling interest in property partnerships	(70,806,000)	(48,260,000)		(71,120,000)
Interest expense	(423,346,000)	(431,717,000)		(412,717,000)
Loss from early extinguishment of debt	45,182,000	0		29,540,000
Depreciation and amortization expense	(709,035,000)	(676,666,000)
Transaction costs	(5,036,000)	(1,531,000)		(1,984,000)
General and administrative expense	(151,573,000)	(133,112,000)		(140,777,000)
Gains (losses) from investments in securities	(5,626,000)	(5,261,000)		(6,417,000)
Interest and other income (loss)	(5,704,000)	(5,953,000)		(18,939,000)
Gains on sales of real estate	(125,198,000)	(631,945,000)		(858,000)
Income (loss) from unconsolidated joint ventures	2,570,000	85,110,000		(46,592,000)
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	561,993,000	979,979,000		580,102,000
Preferred Stock Redemption Charge		0		0
Preferred dividends / distributions	2,560,000	10,500,000		10,500,000
Noncontrolling interest in property partnerships	70,806,000	48,260,000		71,120,000
Interest expense	423,346,000	431,717,000		412,717,000
Loss from early extinguishment of debt	45,182,000	0		29,540,000
Impairment loss	0	0		22,272,000
Depreciation and amortization expense	709,035,000	676,666,000		669,956,000
Transaction costs	5,036,000	1,531,000		1,984,000
Operating expense	12,487,000	11,626,000		10,386,000
General and administrative expense	151,573,000	133,112,000		140,777,000
Gains (losses) from investments in securities	5,626,000	5,261,000		6,417,000
Interest and other income (loss)	5,704,000	5,953,000		18,939,000
Gains on sales of real estate	125,198,000	631,945,000		858,000
Income (loss) from unconsolidated joint ventures	2,570,000	85,110,000		(46,592,000)
Other revenue	12,487,000	11,626,000		10,386,000
Company's share of Net Operating Income	1,735,740,000	1,626,131,000		1,739,850,000
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(27,697,000)	(29,641,000)		(40,039,000)
Management Service [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	27,697,000	29,641,000		40,039,000
Management Service [Member] | Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(27,697,000)	(29,641,000)		(40,039,000)
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	27,697,000	29,641,000		40,039,000
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	186,304,000	162,887,000		183,989,000
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	186,304,000	162,887,000		183,989,000
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	$ 186,304,000	$ 162,887,000		$ 183,989,000

[1] For the year ended December 31, 2020, represents the gain on sale of Annapolis Junction Building Eight and two land parcels. For the year ended December 31, 2019, represents the gain on sale of 540 Madison Avenue recognized by the joint venture. During 2008, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture resulting in a basis differential between the carrying value of the Company’s investment in the joint venture and the joint venture’s basis in the assets and liabilities of the property. As a result of the historical basis difference, the Company recognized a gain on sale of real estate totaling approximately $47.2 million for the year ended December 31, 2019, which consists of its share of the gain on sale reported by the joint venture as well as an adjustment for the basis differential. The gain on sale of real estate is included in Income (loss) from Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations.