Noncontrolling Interests Redeemable common units of Boston Properties Limited Partnership (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Conversion of redeemable partnership units	$ 0	$ 0	$ 0
Cumulative effect of a change in accounting principle	5,496	(2,035)
Boston Properties Limited Partnership
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Cumulative effect of a change in accounting principle	4,933	(272)
Noncontrolling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Conversion of redeemable partnership units	(24,311)	(22,879)	(15,374)
Cumulative effect of a change in accounting principle	563	(1,763)
Noncontrolling Interest [Member] | Boston Properties Limited Partnership
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning Balance	2,292,263	2,262,040	2,286,689
Contributions	34,680	31,743	31,395
Net income	(66,807)	52,210	59,260
Distributions	(62,731)	(54,494)	(49,087)
Conversion of redeemable partnership units	(2,880)	(16,916)	(6,461)
Unearned compensation	2,181	1,650	(3,464)
Cumulative effect of a change in accounting principle	563	(1,763)
Other Comprehensive Income (Loss)	304	206	(4,379)
Adjustment to reflect redeemable partnership units at redemption value	(330,596)	17,587	(51,913)
Ending Balance	$ 2,000,591	$ 2,292,263	$ 2,262,040