Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company's common shareholders / unitholders	$ 143,047	$ 91,624
Preferred Stock Redemption Charge	0	(6,412)
Preferred dividends / distributions	0	(2,560)
Noncontrolling interest-common units of the Operating Partnership	(16,361)	(11,084)
Noncontrolling interest in property partnerships	(17,549)	(16,467)
Interest expense	(101,228)	(107,902)
Loss from early extinguishment of debt	0	898
Company's share of net operating income from joint ventures	(469,316)	(443,947)
Depreciation and amortization expense	(177,624)	(176,565)
Transaction costs	0	(331)
General and administrative expense	(43,194)	(44,959)
Gains (losses) from investments in securities	2,262	(1,659)
Interest and other income (loss)	(1,228)	(1,168)
Gains on sales of real estate	(22,701)	0
Income (loss) from unconsolidated joint ventures	(2,189)	(5,225)
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	143,047	91,624
Preferred Stock Redemption Charge	0	6,412
Preferred dividends / distributions	0	2,560
Noncontrolling interest-common units of the Operating Partnership	16,361	11,084
Noncontrolling interest in property partnerships	17,549	16,467
Interest expense	101,228	107,902
Loss from early extinguishment of debt	0	898
Depreciation and amortization expense	177,624	176,565
Transaction costs	0	331
Operating expense	4,065	3,505
General and administrative expense	43,194	44,959
Gains (losses) from investments in securities	(2,262)	1,659
Interest and other income (loss)	1,228	1,168
Gains on sales of real estate	22,701	0
Income (loss) from unconsolidated joint ventures	(2,189)	(5,225)
Other revenue	4,065	3,505
Company's share of Net Operating Income	459,582	424,366
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(30,373)	(25,556)
Loss from early extinguishment of debt	1,327	0
Company's share of net operating income from joint ventures	37,321	24,795
Depreciation and amortization expense	(44,664)	(34,103)
Transaction costs	0	(7)
Income (loss) from unconsolidated joint ventures	(2,189)	(5,225)
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	161,829	105,773
Preferred Stock Redemption Charge	0	(6,412)
Preferred dividends / distributions	0	(2,560)
Noncontrolling interest in property partnerships	(17,549)	(16,467)
Interest expense	(101,228)	(107,902)
Loss from early extinguishment of debt	0	898
Depreciation and amortization expense	(175,886)	(173,500)
Transaction costs	0	(331)
General and administrative expense	(43,194)	(44,959)
Gains (losses) from investments in securities	2,262	(1,659)
Interest and other income (loss)	(1,228)	(1,168)
Gains on sales of real estate	(23,384)	0
Income (loss) from unconsolidated joint ventures	(2,189)	(5,225)
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	161,829	105,773
Preferred Stock Redemption Charge	0	6,412
Preferred dividends / distributions	0	2,560
Noncontrolling interest in property partnerships	17,549	16,467
Interest expense	101,228	107,902
Loss from early extinguishment of debt	0	898
Depreciation and amortization expense	175,886	173,500
Transaction costs	0	331
Operating expense	4,065	3,505
General and administrative expense	43,194	44,959
Gains (losses) from investments in securities	(2,262)	1,659
Interest and other income (loss)	1,228	1,168
Gains on sales of real estate	23,384	0
Income (loss) from unconsolidated joint ventures	(2,189)	(5,225)
Other revenue	4,065	3,505
Company's share of Net Operating Income	459,582	424,366
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(5,831)	(6,803)
Management Service [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	5,831	6,803
Management Service [Member] | Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(5,831)	(6,803)
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	5,831	6,803
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	47,055	44,376
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	47,055	44,376
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	$ 47,055	$ 44,376