Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Basic Earnings:
Net income attributable to the Company's common shareholders / unitholders	$ 117,337	$ 76,753	$ 348,086	$ 355,114
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	154,355,000	153,754,000	154,132,000	153,681,000
Net income (in dollars per share / unit)	$ 0.76	$ 0.50	$ 2.26	$ 2.31
Allocation of undistributed earnings to participating securities (numerator)	$ (7)		$ (15)	$ (189)
Allocation of undistributed earnings to participating securities (in shares)	0		0	0
Allocation of undistributed earnings to participating securities (in dollars per shares / units)	$ 0		$ 0	$ 0
Net income attributable to the Company's common shareholders / unitholders	$ 117,330		$ 348,071	$ 354,925
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	154,355,000		154,132,000	153,681,000
Net income attributable to the Company's common shareholders / unitholders (in dollars per share / unit)	$ 0.76		$ 2.26	$ 2.31
Effect of Dilutive Securities:
Stock Based Compensation, Income (Numerator)	$ 0	$ 0	$ 0	$ 0
Stock Based Compensation, Shares / Units (Denominator)	128,000	382,000	212,000	290,000
Stock Based Compensation, Per Share / Unit Amount (in dollars per share / unit)	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Diluted Earnings:
Net income attributable to the Company's common shareholders / unitholders (Numerator)	$ 117,330	$ 76,753	$ 348,071	$ 354,925
Net income attributable to to the Company's shareholders / unitholder (number of shares)	154,483,000	154,136,000	154,344,000	153,971,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.76	$ 0.50	$ 2.26	$ 2.31
Boston Properties Limited Partnership
Entity Information [Line Items]
Redeemable Common Units	17,336,000	17,625,000	17,517,000	17,672,000
Basic Earnings:
Net income attributable to the Company's common shareholders / unitholders	$ 132,693	$ 91,306	$ 395,199	$ 408,540
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	171,691,000	171,379,000	171,649,000	171,353,000
Net income (in dollars per share / unit)	$ 0.77	$ 0.53	$ 2.30	$ 2.38
Allocation of undistributed earnings to participating securities (numerator)	$ (8)		$ (17)	$ (210)
Allocation of undistributed earnings to participating securities (in shares)	0		0	0
Allocation of undistributed earnings to participating securities (in dollars per shares / units)	$ 0		$ 0	$ 0.00
Net income attributable to the Company's common shareholders / unitholders	$ 132,685		$ 395,182	$ 408,330
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	171,691,000		171,649,000	171,353,000
Net income attributable to the Company's common shareholders / unitholders (in dollars per share / unit)	$ 0.77		$ 2.30	$ 2.38
Effect of Dilutive Securities:
Stock Based Compensation, Income (Numerator)	$ 0	$ 0	$ 0	$ 0
Stock Based Compensation, Shares / Units (Denominator)	128,000	382,000	212,000	290,000
Stock Based Compensation, Per Share / Unit Amount (in dollars per share / unit)	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Diluted Earnings:
Net income attributable to the Company's common shareholders / unitholders (Numerator)	$ 132,685	$ 91,306	$ 395,182	$ 408,330
Net income attributable to to the Company's shareholders / unitholder (number of shares)	171,819,000	171,761,000	171,861,000	171,643,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.77	$ 0.53	$ 2.30	$ 2.38