Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 111,703	$ 266,525	$ 203,372	$ 764,232
Net income attributable to the company's common shareholders / unitholders (in shares / units)	156,107,000	155,386,000	156,016,000	155,199,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)	$ 0.72	$ 1.72	$ 1.30	$ 4.92
Allocation of undistributed earnings to participating securities		$ (336)	$ 0	$ (1,344)
Allocation of undistributed earnings to participating securities (in shares / units)		0	0	0
Allocation of undistributed earnings to participating securities (in dollars per share / unit)		$ (0.01)	$ 0	$ 0
Net Income Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic		$ 266,189	$ 203,372	$ 762,888
Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares)		155,386,000	156,016,000
Earnings Per Share After Allccation of Undistributed Earnings to Particiapting Securities Basic (dollars per share)	$ 0.72	$ 1.71	$ 1.30	$ 4.92
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0	$ 0	$ 0
Stock Based Compensation (in shares / units)	412,000	21,000	291,000	134,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ (0.01)	$ 0	$ 0	$ (0.01)
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders	$ 111,703	$ 266,189	$ 203,372	$ 762,888
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)	156,519,000	155,407,000	156,307,000	155,333,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.71	$ 1.71	$ 1.30	$ 4.91
Boston Properties Limited Partnership
Redeemable Common Units	17,043,000	17,273,000	17,018,000	17,405,000
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 125,846	$ 301,975	$ 231,619	$ 868,308
Net income attributable to the company's common shareholders / unitholders (in shares / units)	173,150,000	172,659,000	173,034,000	172,604,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)	$ 0.73	$ 1.75		$ 5.03
Allocation of undistributed earnings to participating securities		$ (374)		$ (1,495)
Allocation of undistributed earnings to participating securities (in shares / units)		0		0
Allocation of undistributed earnings to participating securities (in dollars per share / unit)		$ 0		$ (0.01)
Net Income Available To Common Stockholders After Allocation of Undistributed Earnings to Participating Securities Basic		$ 301,601	$ 231,619	$ 866,813
Weighted Average Number Of Shares Outstanding After Allocation of Undistributed Earnings to Participating Securities Basic (in shares)		172,659,000	173,034,000	172,604,000
Earnings Per Share After Allccation of Undistributed Earnings to Particiapting Securities Basic (dollars per share)	$ 0.73	$ 1.75	$ 1.34	$ 5.02
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0	$ 0	$ 0
Stock Based Compensation (in shares / units)	412,000	21,000	291,000	134,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ 0	$ 0	$ 0	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders	$ 125,846	$ 301,601	$ 231,619	$ 866,813
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)	173,562,000	172,680,000	173,325,000	172,738,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.73	$ 1.75	$ 1.34	$ 5.02