Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders		$ 98,105	$ 176,021
Preferred Stock Dividends / Distributions		(2,625)	(2,625)
Noncontrolling interest-common units of the Operating Partnership		(11,599)	(20,432)
Noncontrolling interest in property partnerships		(18,830)	(17,234)
Interest expense		(101,009)	(90,220)
Net operating income from unconsolidated joint ventures		25,349	16,060
Depreciation and amortization expense		(164,594)	(165,797)
Transaction costs		(460)	(21)
Payroll and related costs from management service contracts		(7,863)	(8,073)
General and administrative expense		(41,762)	(35,894)
Net operating income attributable to noncontrolling interests in property partnerships		47,085	45,909
Gains (losses) from investments in securities		(2,969)	126
Interest and other income		(3,753)	(1,648)
Income from unconsolidated joint ventures		(213)	(461)
Direct reimbursement of payroll and related costs from management service contracts	[1]	(8,938)	(9,102)
Development and management services revenue		(9,277)	(8,405)
Company's Share of Net Operating Income		425,979	371,610
Business Intersegment, Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders		98,105	176,021
Preferred Stock Dividends / Distributions		2,625	2,625
Noncontrolling interest-common units of the Operating Partnership		11,599	20,432
Noncontrolling interest in property partnerships		18,830	17,234
Interest expense		101,009	90,220
Impairment loss		24,038	0
Net operating income from unconsolidated joint ventures		25,349	16,060
Depreciation and amortization expense		164,594	165,797
Transaction costs		460	21
Payroll and related costs from management service contracts		3,395	2,885
General and administrative expense		41,762	35,894
Net operating income attributable to noncontrolling interests in property partnerships		47,085	45,909
Gains (losses) from investments in securities		2,969	(126)
Interest and other income		3,753	1,648
(Losses) gains on sales of real estate		(905)	96,397
Income from unconsolidated joint ventures		213	461
Direct reimbursement of payroll and related costs from management service contracts		3,395	2,885
Development and management services revenue		9,277	8,405
Company's Share of Net Operating Income		425,979	371,610
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		113,382	200,907
Preferred Stock Dividends / Distributions		(2,625)	(2,625)
Noncontrolling interest in property partnerships		(18,830)	(17,234)
Interest expense		(101,009)	(90,220)
Depreciation and amortization expense		(162,682)	(163,853)
Transaction costs		(460)	(21)
General and administrative expense		(41,762)	(35,894)
Gains (losses) from investments in securities		(2,969)	126
Interest and other income		(3,753)	(1,648)
Income from unconsolidated joint ventures		(213)	(461)
Development and management services revenue		(9,277)	(8,405)
Boston Properties Limited Partnership | Business Intersegment, Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders		113,382	200,907
Preferred Stock Dividends / Distributions		2,625	2,625
Noncontrolling interest in property partnerships		18,830	17,234
Interest expense		101,009	90,220
Impairment loss		22,272	0
Net operating income from unconsolidated joint ventures		25,349	16,060
Depreciation and amortization expense		162,682	163,853
Transaction costs		460	21
Payroll and related costs from management service contracts		3,395	2,885
General and administrative expense		41,762	35,894
Net operating income attributable to noncontrolling interests in property partnerships		47,085	45,909
Gains (losses) from investments in securities		2,969	(126)
Interest and other income		3,753	1,648
(Losses) gains on sales of real estate		(905)	98,907
Income from unconsolidated joint ventures		213	461
Direct reimbursement of payroll and related costs from management service contracts		3,395	2,885
Development and management services revenue		9,277	8,405
Company's Share of Net Operating Income		$ 425,979	$ 371,610

[1] Rental Revenue is equal to total Revenue per the Company's Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.