Real Estate Activity During the Nine Months Ended September 30, 2014 (Summary Of The Discontinued Operations Related To Montvale Center, 303 Almaden Blvd, 1301 New York Avenue, One Preserve Parkway and 10 & 20 Burlington Mall Road) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenue	$ 618,803	$ 571,481	$ 1,783,291	$ 1,559,340
Expenses
Depreciation and amortization	157,245	153,253	466,143	406,162
Total expenses	404,000	384,728	1,190,318	1,076,212
Operating income	214,803	186,753	592,973	483,128
Other expense
Interest expense	113,308	122,173	337,839	325,746
Income from discontinued operations	0	1,677	0	7,486
Noncontrolling interest in income (loss) from discontinued operations - common units of the Operating Partnership	0	(8,970)	0	(11,450)
Income from discontinued operations attributable to Boston Properties, Inc.		79,155		99,425
Gain on sale of real estate from discontinued operations	0	86,448	0	86,448
Gain on forgiveness of debt from discontinued operations	0	0	0	20,182
Impairment loss from discontinued operations	0	0	0	(3,241)
Montvale Center, 303 Almaden Blvd, 1301 New York Avenue, One Preserve Parkway and 10 & 20 Burlington Mall Road [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenue				17,962
Expenses
Operating				6,290
Depreciation and amortization				3,826
Total expenses				10,116
Operating income				7,846
Other expense
Interest expense				360
Income from discontinued operations				7,486
Noncontrolling interest in income (loss) from discontinued operations - common units of the Operating Partnership				(752)
Income from discontinued operations attributable to Boston Properties, Inc.				6,734
Gain on sale of real estate from discontinued operations				86,448
Gain on forgiveness of debt from discontinued operations				20,182
Impairment loss from discontinued operations				(3,241)
Noncontrolling interest in gain on forgiveness of debt from discontinued operations - common units of the Operating Partnership				(10,698)
Gain on forgiveness of debt and impairment losses from discontinued operations attributable to Boston Properties, Inc.				92,691
1301 New York Avenue, One Preserve Parkway and 10 & 20 Burlington Mall Road [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenue		4,112
Expenses
Operating		1,495
Depreciation and amortization		940
Total expenses		2,435
Operating income		1,677
Other expense
Interest expense		0
Income from discontinued operations		1,677
Noncontrolling interest in income (loss) from discontinued operations - common units of the Operating Partnership		(167)
Income from discontinued operations attributable to Boston Properties, Inc.		1,510
Gain on sale of real estate from discontinued operations		86,448
Gain on forgiveness of debt from discontinued operations		0
Impairment loss from discontinued operations		0
Noncontrolling interest in gain on forgiveness of debt from discontinued operations - common units of the Operating Partnership		(8,803)
Gain on forgiveness of debt and impairment losses from discontinued operations attributable to Boston Properties, Inc.		$ 77,645