Segment Reporting (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Add:	$ 162,822	$ 163,830	$ 480,552	$ 454,786
Development and management services income	8,024	8,178	25,734	24,699
Income from unconsolidated joint ventures	9,217	11,326	42,129	28,184
Interest and other income	4,001	1,252	8,029	4,179
Gains (losses) from investments in securities	587	(860)	1,202	(481)
Income (loss) from discontinued operations		20	884	(60)
Gain on sale of real estate from discontinued operations			36,877
Gain on forgiveness of debt from discontinued operations			17,807
General and administrative expense	19,757	16,917	66,442	60,281
Transaction costs	1,140	474	3,252	1,907
Depreciation and amortization expense	111,360	108,674	331,943	327,526
Interest expense	105,030	95,117	308,168	288,225
Losses from early extinguishments of debt	(5,494)		(4,453)
Noncontrolling interest in property partnerships	458	86	1,461	1,118
Noncontrolling interest-redeemable preferred units of the Operating Partnership	874	832	2,440	2,497
Noncontrolling interest-common units of the Operating Partnership	7,002	8,989	23,393	23,417
Noncontrolling interest in discontinued operations-common units of the Operating Partnership		2	6,092	(8)
Net income attributable to Boston Properties, Inc.	57,769	70,542	241,473	171,359
Business Intersegment, Eliminations [Member]
Segment Reporting Information [Line Items]
Add:	287,055	281,717	856,455	819,801
Development and management services income	8,024	8,178	25,734	24,699
Income from unconsolidated joint ventures	9,217	11,326	42,129	28,184
Interest and other income	4,001	1,252	8,029	4,179
Gains (losses) from investments in securities	587	(860)	1,202	(481)
Income (loss) from discontinued operations		20	884	(60)
Gain on sale of real estate from discontinued operations			36,877
Gain on forgiveness of debt from discontinued operations			17,807
General and administrative expense	19,757	16,917	66,442	60,281
Transaction costs	1,140	474	3,252	1,907
Depreciation and amortization expense	111,360	108,674	331,943	327,526
Interest expense	105,030	95,117	308,168	288,225
Losses from early extinguishments of debt	5,494		4,453
Noncontrolling interest in property partnerships	458	86	1,461	1,118
Noncontrolling interest-redeemable preferred units of the Operating Partnership	874	832	2,440	2,497
Noncontrolling interest-common units of the Operating Partnership	7,002	8,989	23,393	23,417
Noncontrolling interest in discontinued operations-common units of the Operating Partnership		2	6,092	(8)
Net income attributable to Boston Properties, Inc.	$ 57,769	$ 70,542	$ 241,473	$ 171,359