Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Earnings Per Share [Abstract]
Net income attributable to Boston Properties, Inc., Income (Numerator)	$ 70,542	$ 57,668	$ 171,359	$ 171,786
Net income attributable to Boston Properties Inc., Shares (Denominator)	147,006	139,595	145,006	139,215
Net income attributable to Boston Properties Inc., Per Share Amount	$ 0.48	$ 0.41	$ 1.18	$ 1.23
Stock Based Compensation and Exchangeable Senior Notes, Income (Numerator)
Stock Based Compensation and Exchangeable Senior Notes, Shares (Denominator)	616	598	619	659
Stock Based Compensation and Exchangeable Senior Notes, Per Share Amount	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Diluted Earnings: Net income, Income (Numerator)	$ 70,542	$ 57,668	$ 171,359	$ 171,786
Diluted Earnings: Net income, Shares (Denominator)	147,622	140,193	145,625	139,874
Diluted Earnings: Net income, Per Share Amount	$ 0.48	$ 0.41	$ 1.18	$ 1.23