Summary Of Significant Accounting Policies GAAP Reconciliation Of Net Income To Taxable Income (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Entity Information [Line Items]
Net income attributable to the Company		$ 137,851	$ 184,082	$ 79,460	$ 171,182	$ 174,510	$ 127,724	$ 76,527	$ 54,034	$ 583,106	$ 443,611		$ 749,811
Straight line rent and net above and below-market rent adjustments										(92,483)	(91,733)		(74,445)
Book/tax differences from depreciation and amortization										307,115	239,681		170,370
Book/Tax differences from interest expense										(43,349)	(43,148)		(7,912)
Book/tax differences on gains/(losses) from capital transactions										(74,482)	943,778	[1]	(124,413)
Book/tax differences from stock-based compensation										22,008	32,483		42,146
Tangible Property Regulations	[2]									(74,887)	(442,650)		0
Other book/tax differences, net										(15,259)	(7,945)		(4,885)
Taxable Income										611,769	1,074,077		750,672
One-time deduction for Tangible Repair Regulations											385,600
Boston Properties Limited Partnership [Member]
Entity Information [Line Items]
Net income attributable to the Company		$ 156,901	$ 207,626	$ 90,852	$ 193,369	$ 204,759	$ 144,715	$ 87,436	$ 62,219	659,248	509,629		849,573
Straight line rent and net above and below-market rent adjustments										(103,227)	(102,319)		(82,904)
Book/tax differences from depreciation and amortization										329,629	253,590		174,384
Book/Tax differences from interest expense										(48,385)	(48,128)		(8,811)
Book/tax differences on gains/(losses) from capital transactions										(67,602)	1,065,518	[3]	(138,300)
Book/tax differences from stock-based compensation										24,565	36,232		46,935
Tangible Property Regulations	[4]									(83,587)	(493,731)		0
Other book/tax differences, net										(14,561)	(11,403)		8,589
Taxable Income										$ 696,080	1,209,388		$ 849,466
One-time deduction for Tangible Repair Regulations											$ 430,100

[1] Consists primarily of the gain on sale of real estate for tax purposes related to the October 2014 sale by the Company of a 45% interest in each of 601 Lexington Avenue in New York City and Atlantic Wharf Office Building and 100 Federal Street in Boston, which was accounted for as an equity transaction for GAAP purposes with no gain on sale of real estate recognized

[2] In September 2013, the Internal Revenue Service released final Regulations governing when taxpayers like Boston Properties, Inc. must capitalize and depreciate costs for acquiring, maintaining, repairing and replacing tangible property and when taxpayers can deduct such costs. These final Regulations were effective for tax years beginning on or after January 1, 2014. These Regulations permitted Boston Properties, Inc. to deduct certain types of expenditures that were previously required to be capitalized. The Regulations also allowed Boston Properties, Inc. to make a one-time election in 2014 to immediately deduct certain amounts that were capitalized in previous years that are not required to be capitalized under the new Regulations. The one-time deduction included above totaled approximately $385.6 million for the year ended December 31, 2014.

[3] Consists primarily of the gain on sale of real estate for tax purposes related to the October 2014 sale by the Company of a 45% interest in each of 601 Lexington Avenue in New York City and Atlantic Wharf Office Building and 100 Federal Street in Boston, which was accounted for as an equity transaction for GAAP purposes with no gain on sale of real estate recognized

[4] In September 2013, the Internal Revenue Service released final Regulations governing when taxpayers like Boston Properties Limited Partnership must capitalize and depreciate costs for acquiring, maintaining, repairing and replacing tangible property and when taxpayers can deduct such costs. These final Regulations were effective for tax years beginning on or after January 1, 2014. These Regulations permitted Boston Properties Limited Partnership to deduct certain types of expenditures that were previously required to be capitalized. The Regulations also allowed Boston Properties Limited Partnership to make a one-time election in 2014 to immediately deduct certain amounts that were capitalized in previous years that are not required to be capitalized under the new Regulations. The one-time deduction included above totaled approximately $430.1 million for the year ended December 31, 2014.