Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 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	$ 497,496	$ 98,105
Preferred dividends / distributions	(2,625)	(2,625)
Noncontrolling interest-common units of the Operating Partnership	(57,539)	(11,599)
Noncontrolling interest in property partnerships	(19,486)	(18,830)
Interest expense	(101,591)	(101,009)
Company's share of net operating income from joint ventures	(471,653)	(447,715)
Depreciation and amortization expense	(171,094)	(164,594)
Transaction costs	(615)	(460)
General and administrative expense	(36,454)	(41,762)
Gains (losses) from investments in securities	5,445	(2,969)
Interest and other income	(3,017)	(3,753)
Income from unconsolidated joint ventures	369	(213)
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	497,496	98,105
Preferred dividends / distributions	2,625	2,625
Noncontrolling interest-common units of the Operating Partnership	57,539	11,599
Noncontrolling interest in property partnerships	19,486	18,830
Interest expense	101,591	101,009
Impairment losses	0	24,038
Depreciation and amortization expense	171,094	164,594
Transaction costs	615	460
Payroll and related costs from management services contracts	3,237	3,395
General and administrative expense	36,454	41,762
Gains (losses) from investments in securities	(5,445)	2,969
Interest and other income	3,017	3,753
Gains on sales of real estate	410,165	(905)
Income from unconsolidated joint ventures	(369)	213
Other revenue	3,237	3,395
Net Operating Income	452,750	425,979
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	566,333	113,382
Preferred dividends / distributions	(2,625)	(2,625)
Noncontrolling interest in property partnerships	(19,486)	(18,830)
Interest expense	(101,591)	(101,009)
Depreciation and amortization expense	(169,285)	(162,682)
Transaction costs	(615)	(460)
General and administrative expense	(36,454)	(41,762)
Gains (losses) from investments in securities	5,445	(2,969)
Interest and other income	(3,017)	(3,753)
Income from unconsolidated joint ventures	369	(213)
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	566,333	113,382
Preferred dividends / distributions	2,625	2,625
Noncontrolling interest in property partnerships	19,486	18,830
Interest expense	101,591	101,009
Impairment losses	0	22,272
Depreciation and amortization expense	169,285	162,682
Transaction costs	615	460
Payroll and related costs from management services contracts	3,237	3,395
General and administrative expense	36,454	41,762
Gains (losses) from investments in securities	(5,445)	2,969
Interest and other income	3,017	3,753
Gains on sales of real estate	419,654	(905)
Income from unconsolidated joint ventures	(369)	213
Other revenue	3,237	3,395
Net Operating Income	452,750	425,979
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(22,583)	(20,757)
Company's share of net operating income from joint ventures	(28,758)	(25,349)
Depreciation and amortization expense	(32,035)	(28,646)
Income from unconsolidated joint ventures	369	(213)
Unconsolidated Joint Ventures [Member] \| Business Intersegment, Eliminations [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	(28,758)	(25,349)
Unconsolidated Joint Ventures [Member] \| Boston Properties Limited Partnership \| Business Intersegment, Eliminations [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	(28,758)	(25,349)
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Payroll and related costs from management services contracts	(3,237)	(3,395)
Other revenue	(7,879)	(9,277)
Management Service [Member] \| Business Intersegment, Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	7,879	9,277
Management Service [Member] \| Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Payroll and related costs from management services contracts	(3,237)	(3,395)
Other revenue	(7,879)	(9,277)
Management Service [Member] \| Boston Properties Limited Partnership \| Business Intersegment, Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	7,879	9,277
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	47,661	47,085
Noncontrolling interest - property partnerships [Member] \| Business Intersegment, Eliminations [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	47,661	47,085
Noncontrolling interest - property partnerships [Member] \| Boston Properties Limited Partnership \| Business Intersegment, Eliminations [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	$ 47,661	$ 47,085

The net result for the period of deducting property operating expenses from property operating revenues.

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