Summary Of Significant Accounting Policies GAAP Reconciliation Of Net Income To Taxable Income (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Reconciliation of GAAP net income to taxable income [Abstract]
One-time deduction for Tangible Repair Regulations	$ 385,600,000
Net income attributable to Boston Properties, Inc.	443,611,000		749,811,000	289,650,000
Straight-line rent adjustments	(91,733,000)		(74,445,000)	(80,281,000)
Book/Tax differences from depreciation and amortization	239,681,000		170,370,000	105,599,000
Income Tax Reconciliation, Book/Tax Differences On Interest Expense	(43,148,000)		(7,912,000)	27,660,000
Book/Tax differences on gains/losses from capital transactions	943,778,000		(124,413,000)	(22,408,000)
Book/Tax differences from stock-based compensation	32,483,000		42,146,000	19,660,000
Income Tax Reconciliation, Book/Tax Differences On Tngible Property Regulations	(442,650,000)	[1]	0	0
Other book/tax differences, net	(7,945,000)		(4,885,000)	7,801,000
Taxable income	$ 1,074,077,000		$ 750,672,000	$ 347,681,000

[1] (1) In September 2013, the Internal Revenue Service released final Regulations governing when taxpayers like the Company must capitalize and depreciate costs for acquiring, maintaining, repairing and replacing tangible property and when taxpayers can deduct such costs. These final Regulations are effective for tax years beginning on or after January 1, 2014. These Regulations permitted the Company to deduct certain types of expenditures that were previously required to be capitalized. The Regulations also allowed the Company to make a one-time election to immediately deduct certain amounts that were capitalized in previous years that are not required to be capitalized under the new Regulations.