Segment Information (Reconciliation of Net Operating Income to Net Income) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Segment Reporting Information [Line Items]
Net Operating Income	$ 164,510	$ 151,082	$ 456,665	$ 461,623
Development and management services income	8,180	6,439	24,706	34,267
Income from unconsolidated joint ventures	11,326	11,565	28,184	26,940
Interest and other income	1,252	1,814	4,179	5,641
Gain on sales of real estate				2,734
General and administrative expense	17,340	18,067	62,052	62,537
Acquisition costs	51	1,893	136	1,893
Suspension of development				(7,200)
Depreciation and amortization expense	109,495	81,133	330,003	245,608
Losses (gains) from investments in securities	(860)	731	(481)	253
Interest expense	95,777	97,103	290,164	285,887
Losses from early extinguishments of debt				8,221
Noncontrolling interest in property partnerships	86	889	1,118	2,557
Noncontrolling interest-redeemable preferred units of the Operating Partnership	832	820	2,497	2,548
Noncontrolling interest-common units of the Operating Partnership	8,991	8,712	23,409	25,841
Noncontrolling interest-common units of the Operating Partnership				351
Net income attributable to Boston Properties, Inc.	70,542	57,668	171,359	171,786
Business Intersegment, Eliminations [Member]
Segment Reporting Information [Line Items]
Net Operating Income	283,216	245,736	824,150	730,194
Development and management services income	8,180	6,439	24,706	34,267
Income from unconsolidated joint ventures	11,326	11,565	28,184	26,940
Interest and other income	1,252	1,814	4,179	5,641
Gain on sales of real estate				2,734
General and administrative expense	17,340	18,067	62,052	62,537
Acquisition costs	51	1,893	136	1,893
Suspension of development				(7,200)
Depreciation and amortization expense	109,495	81,133	330,003	245,608
Losses (gains) from investments in securities	860	(731)	481	(253)
Interest expense	95,777	97,103	290,164	285,887
Losses from early extinguishments of debt				8,221
Noncontrolling interest in property partnerships	86	889	1,118	2,557
Noncontrolling interest-redeemable preferred units of the Operating Partnership	832	820	2,497	2,548
Noncontrolling interest-common units of the Operating Partnership	8,991	8,712	23,409	25,841
Noncontrolling interest-common units of the Operating Partnership				351
Net income attributable to Boston Properties, Inc.	$ 70,542	$ 57,668	$ 171,359	$ 171,786