Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic Earnings:
Net income attributable to the Company's common shareholders / unitholders	$ 176,021	$ 97,083
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	154,385,000	153,860,000
Net income (in dollars per share / unit)	$ 1.14	$ 0.63
Allocation of undistributed earnings to participating securities (numerator)	$ (127)
Allocation of undistributed earnings to participating securities (in shares)	0
Allocation of undistributed earnings to participating securities (in dollars per shares / units)	$ 0
Net income attributable to the Company's common shareholders / unitholders	$ 175,894
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	154,385,000
Net income attributable to the Company's common shareholders / unitholders (in dollars per share / unit)	$ 1.14
Effect of Dilutive Securities:
Stock Based Compensation, Income (Numerator)	$ 0	$ 0
Stock Based Compensation, Shares / Units (Denominator)	320,000	354,000
Stock Based Compensation, Per Share / Unit Amount (in dollars per share / unit)	$ 0.00	$ 0.00
Diluted Earnings:
Net income attributable to the Company's common shareholders / unitholders (Numerator)	$ 175,894	$ 97,083
Net income attributable to to the Company's shareholders / unitholder (number of shares)	154,705,000	154,214,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 1.14	$ 0.63
Boston Properties Limited Partnership
Entity Information [Line Items]
Redeemable Common Units	17,482,000	17,721,000
Basic Earnings:
Net income attributable to the Company's common shareholders / unitholders	$ 200,907	$ 110,662
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	171,867,000	171,581,000
Net income (in dollars per share / unit)	$ 1.17	$ 0.64
Allocation of undistributed earnings to participating securities (numerator)	$ (141)
Allocation of undistributed earnings to participating securities (in shares)	0
Allocation of undistributed earnings to participating securities (in dollars per shares / units)	$ 0
Net income attributable to the Company's common shareholders / unitholders	$ 200,766
Net income attributable to the Company's common shareholders / unitholders (in shares / units)	171,867,000
Net income attributable to the Company's common shareholders / unitholders (in dollars per share / unit)	$ 1.17
Effect of Dilutive Securities:
Stock Based Compensation, Income (Numerator)	$ 0	$ 0
Stock Based Compensation, Shares / Units (Denominator)	320,000	354,000
Stock Based Compensation, Per Share / Unit Amount (in dollars per share / unit)	$ 0.00	$ 0.00
Diluted Earnings:
Net income attributable to the Company's common shareholders / unitholders (Numerator)	$ 200,766	$ 110,662
Net income attributable to to the Company's shareholders / unitholder (number of shares)	172,187,000	171,935,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 1.17	$ 0.64