Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Operating Income	$ 176,897	$ 128,002
Development and management services income	5,216	8,733
Income from unconsolidated joint ventures	2,816	8,721
Interest and other income	1,311	1,471
Gains from investments in securities	286	735
Gain on forgiveness of debt from discontinued operations	0	20,182
General and administrative expense	29,905	45,516
Transaction costs	437	443
Depreciation and amortization expense	154,270	119,453
Interest expense	113,554	100,433
Impairment loss	0	8,306
Impairment loss from discontinued operations	0	3,241
Noncontrolling interest in property partnerships	4,354	2,574
Noncontrolling interest-redeemable preferred units of the Operating Partnership	619	1,180
Noncontrolling interest-common units of the Operating Partnership	6,160	4,111
Noncontrolling interest in discontinued operations-common units of the Operating Partnership	0	2,066
Net income attributable to Boston Properties, Inc.	56,623	48,000
Business Intersegment, Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Operating Income	356,293	292,987
Development and management services income	5,216	8,733
Income from unconsolidated joint ventures	2,816	8,721
Interest and other income	1,311	1,471
Gains from investments in securities	286	735
Income from discontinued operations	0	2,494
Gain on forgiveness of debt from discontinued operations	0	20,182
General and administrative expense	29,905	45,516
Transaction costs	437	443
Depreciation and amortization expense	154,270	119,453
Interest expense	113,554	100,433
Impairment loss	0	8,306
Impairment loss from discontinued operations	0	3,241
Noncontrolling interest in property partnerships	4,354	2,574
Noncontrolling interest-redeemable preferred units of the Operating Partnership	619	1,180
Noncontrolling interest-common units of the Operating Partnership	6,160	4,111
Noncontrolling interest in discontinued operations-common units of the Operating Partnership	0	2,066
Net income attributable to Boston Properties, Inc.	$ 56,623	$ 48,000