Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 497,496	$ 98,105
Net income attributable to the company's common shareholders / unitholders (in shares / units)	155,011,000	154,525,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)	$ 3.21	$ 0.63
Allocation of undistributed earnings to participating securities	$ (1,011)
Allocation of undistributed earnings to participating securities (in shares / units)	0
Allocation of undistributed earnings to participating securities (in dollars per share / unit)	$ (0.01)
Net income attributable to the company's common shareholders / unitholders, after allocation of undistributed earnings to participating securities	$ 496,485	$ 98,105
Net income attributable to the company's common shareholders / unitholders, after allocation of undistributed earnings to participating securities (in shares / units)	155,011,000	154,525,000
Net income attributable to the company's common shareholders / unitholders, after allocation of undistributed earnings to participating securities (in dollars per share / unit)	$ 3.20	$ 0.63
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0
Stock Based Compensation (in shares / units)	247,000	319,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ 0	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders	$ 496,485	$ 98,105
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)	155,258,000	154,844,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 3.20	$ 0.63
Boston Properties Limited Partnership
Redeemable Common Units	17,538,000	17,606,000
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 566,333	$ 113,382
Net income attributable to the company's common shareholders / unitholders (in shares / units)	172,549,000	172,131,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)	$ 3.28	$ 0.66
Allocation of undistributed earnings to participating securities	$ (1,126)
Allocation of undistributed earnings to participating securities (in shares / units)	0
Allocation of undistributed earnings to participating securities (in dollars per share / unit)	$ 0
Net income attributable to the company's common shareholders / unitholders, after allocation of undistributed earnings to participating securities	$ 565,207	$ 113,382
Net income attributable to the company's common shareholders / unitholders, after allocation of undistributed earnings to participating securities (in shares / units)	172,549,000	172,131,000
Net income attributable to the company's common shareholders / unitholders, after allocation of undistributed earnings to participating securities (in dollars per share / unit)	$ 3.28	$ 0.66
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0
Stock Based Compensation (in shares / units)	247,000	319,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ (0.01)	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders	$ 565,207	$ 113,382
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)	172,796,000	172,450,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 3.27	$ 0.66