Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	$ 128,681	$ 133,709	$ 304,682	$ 230,764
Preferred Stock Dividends / Distributions	(2,625)	(2,625)	(5,250)	(5,250)
Noncontrolling interest-common units of the Operating Partnership	(14,859)	(15,473)	(35,311)	(26,933)
Noncontrolling interest in property partnerships	(14,400)	(15,203)	(31,634)	(19,627)
Interest expense	(92,204)	(95,143)	(182,424)	(190,677)
Depreciation and amortization expense	(156,417)	(151,919)	(322,214)	(311,124)
Transaction costs	(474)	(299)	(495)	(333)
Payroll and related costs from management services contracts	(1,970)	0	(4,855)	0
General and administrative expense	(28,468)	(27,141)	(64,362)	(58,527)
Gains from early extinguishments of debt	0	(14,354)	0	(14,354)
Gains from investments in securities	(505)	(730)	(379)	(1,772)
Interest and other income	(2,579)	(1,504)	(4,227)	(2,118)
Income from unconsolidated joint ventures	(769)	(3,108)	(1,230)	(6,192)
Direct reimbursements of payroll and related costs from management services contracts	(1,970)	0	(4,855)	0
Development and management services income	(9,305)	(7,365)	(17,710)	(13,837)
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	128,681	133,709	304,682	230,764
Preferred Stock Dividends / Distributions	2,625	2,625	5,250	5,250
Noncontrolling interest-common units of the Operating Partnership	14,859	15,473	35,311	26,933
Noncontrolling interest in property partnerships	14,400	15,203	31,634	19,627
Interest expense	92,204	95,143	182,424	190,677
Depreciation and amortization expense	156,417	151,919	322,214	311,124
Transaction costs	474	299	495	333
Payroll and related costs from management services contracts	1,970	0	4,855	0
General and administrative expense	28,468	27,141	64,362	58,527
Gains on sales of real estate	18,292	3,767	114,689	3,900
Gains from early extinguishments of debt	0	14,354	0	14,354
Gains from investments in securities	505	730	379	1,772
Interest and other income	2,579	1,504	4,227	2,118
Income from unconsolidated joint ventures	769	3,108	1,230	6,192
Direct reimbursements of payroll and related costs from management services contracts	1,970	0	4,855	0
Development and management services income	9,305	7,365	17,710	13,837
Net Operating Income	406,678	410,684	808,137	801,062
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	145,961	151,844	346,868	262,506
Preferred Stock Dividends / Distributions	(2,625)	(2,625)	(5,250)	(5,250)
Noncontrolling interest in property partnerships	(14,400)	(15,203)	(31,634)	(19,627)
Interest expense	(92,204)	(95,143)	(182,424)	(190,677)
Depreciation and amortization expense	(154,474)	(149,834)	(318,327)	(306,892)
Transaction costs	(474)	(299)	(495)	(333)
Payroll and related costs from management services contracts	(1,970)	0	(4,855)	0
General and administrative expense	(28,468)	(27,141)	(64,362)	(58,527)
Gains from early extinguishments of debt	0	(14,354)	0	(14,354)
Gains from investments in securities	(505)	(730)	(379)	(1,772)
Interest and other income	(2,579)	(1,504)	(4,227)	(2,118)
Income from unconsolidated joint ventures	(769)	(3,108)	(1,230)	(6,192)
Direct reimbursements of payroll and related costs from management services contracts	(1,970)	0	(4,855)	0
Development and management services income	(9,305)	(7,365)	(17,710)	(13,837)
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	145,961	151,844	346,868	262,506
Preferred Stock Dividends / Distributions	2,625	2,625	5,250	5,250
Noncontrolling interest in property partnerships	14,400	15,203	31,634	19,627
Interest expense	92,204	95,143	182,424	190,677
Depreciation and amortization expense	154,474	149,834	318,327	306,892
Transaction costs	474	299	495	333
Payroll and related costs from management services contracts	1,970	0	4,855	0
General and administrative expense	28,468	27,141	64,362	58,527
Gains on sales of real estate	18,770	4,344	117,677	4,477
Gains from early extinguishments of debt	0	14,354	0	14,354
Gains from investments in securities	505	730	379	1,772
Interest and other income	2,579	1,504	4,227	2,118
Income from unconsolidated joint ventures	769	3,108	1,230	6,192
Direct reimbursements of payroll and related costs from management services contracts	1,970	0	4,855	0
Development and management services income	9,305	7,365	17,710	13,837
Net Operating Income	$ 406,678	$ 410,684	$ 808,137	$ 801,062