Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss) attributable to the Company	$ (111,826)	$ 360,977	$ 70,290	$ 727,144
Noncontrolling interest-common units of the Operating Partnership	12,626	(40,883)	(8,642)	(82,821)
Noncontrolling interest in property partnerships	(20,909)	(18,801)	(59,337)	(54,896)
Interest expense	(147,812)	(111,846)	(424,492)	(317,216)
Company's share of net operating income from joint ventures	(501,881)	(488,908)	(1,496,376)	(1,442,266)
Loss from unconsolidated joint ventures	247,556	3,524	261,793	1,389
Depreciation and amortization expense	(207,435)	(190,675)	(618,746)	(551,445)
Transaction costs	(751)	(1,650)	(1,970)	(2,146)
General and administrative expense	(31,410)	(32,519)	(131,387)	(110,378)
Unrealized Gain (Loss) on Investments	51	0	(332)	0
Gains (losses) from investments in securities	925	1,571	(2,311)	8,549
Other Income - assignment fee	0	0	0	(6,624)
Interest and other income (loss)	(20,715)	(3,728)	(48,999)	(6,151)
Gains on sales of real estate	(517)	(262,345)	(517)	(381,293)
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss) attributable to the Company	(111,826)	360,977	70,290	727,144
Noncontrolling interest-common units of the Operating Partnership	(12,626)	40,883	8,642	82,821
Noncontrolling interest in property partnerships	20,909	18,801	59,337	54,896
Interest expense	147,812	111,846	424,492	317,216
Loss from unconsolidated joint ventures	(247,556)	(3,524)	(261,793)	(1,389)
Depreciation and amortization expense	207,435	190,675	618,746	551,445
Transaction costs	751	1,650	1,970	2,146
Operating expense	3,906	3,900	13,750	11,204
General and administrative expense	31,410	32,519	131,387	110,378
Unrealized Gain (Loss) on Investments	(51)	0	332	0
Gains (losses) from investments in securities	(925)	(1,571)	2,311	(8,549)
Other Income - assignment fee	0	0	0	6,624
Interest and other income (loss)	20,715	3,728	48,999	6,151
Gains on sales of real estate	517	262,345	517	381,293
Other revenue	3,906	3,900	13,750	11,204
Company's share of Net Operating Income	490,999	475,918	1,473,449	1,407,390
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(60,737)	(40,678)	(176,786)	(103,270)
Loss from unconsolidated joint ventures	247,556	3,524	261,793	1,389
Depreciation and amortization expense	(49,840)	(44,132)	(151,051)	(132,089)
Transaction costs	(78)	65	(179)	(746)
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	39,165	35,316	122,175	108,347
Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss) attributable to the Company	(122,696)	403,578	84,232	819,195
Noncontrolling interest in property partnerships	(20,909)	(18,801)	(59,337)	(54,896)
Interest expense	(147,812)	(111,846)	(424,492)	(317,216)
Loss from unconsolidated joint ventures	247,556	3,524	261,793	1,389
Depreciation and amortization expense	(205,679)	(188,969)	(613,446)	(546,271)
Transaction costs	(751)	(1,650)	(1,970)	(2,146)
General and administrative expense	(31,410)	(32,519)	(131,387)	(110,378)
Unrealized Gain (Loss) on Investments	51	0	(332)	0
Gains (losses) from investments in securities	925	1,571	(2,311)	8,549
Other Income - assignment fee	0	0	0	(6,624)
Interest and other income (loss)	(20,715)	(3,728)	(48,999)	(6,151)
Gains on sales of real estate	(517)	(262,357)	(517)	(385,349)
Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss) attributable to the Company	(122,696)	403,578	84,232	819,195
Noncontrolling interest in property partnerships	20,909	18,801	59,337	54,896
Interest expense	147,812	111,846	424,492	317,216
Loss from unconsolidated joint ventures	(247,556)	(3,524)	(261,793)	(1,389)
Depreciation and amortization expense	205,679	188,969	613,446	546,271
Transaction costs	751	1,650	1,970	2,146
Operating expense	3,906	3,900	13,750	11,204
General and administrative expense	31,410	32,519	131,387	110,378
Unrealized Gain (Loss) on Investments	(51)	0	332	0
Gains (losses) from investments in securities	(925)	(1,571)	2,311	(8,549)
Other Income - assignment fee	0	0	0	6,624
Interest and other income (loss)	20,715	3,728	48,999	6,151
Gains on sales of real estate	517	262,357	517	385,349
Other revenue	3,906	3,900	13,750	11,204
Company's share of Net Operating Income	490,999	475,918	1,473,449	1,407,390
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(9,284)	(7,465)	(28,122)	(19,650)
Management Service [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	9,284	7,465	28,122	19,650
Management Service [Member] | Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(9,284)	(7,465)	(28,122)	(19,650)
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	9,284	7,465	28,122	19,650
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	50,047	48,306	145,102	143,223
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	50,047	48,306	145,102	143,223
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	$ 50,047	$ 48,306	$ 145,102	$ 143,223