Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
General Partners' Capital Account, Units Outstanding (in units)	1,722,336
Limited Partners' Capital Account, Units Outstanding (in units)	152,736,142
Excess stock, par value	$ 0.01	$ 0.01
Excess stock, shares authorized	150,000,000	150,000,000
Excess stock, shares issued	0	0
Excess stock, shares outstanding	0	0
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	154,537,378	154,404,186
Common stock, shares outstanding	154,458,478	154,325,286
Treasury common stock at cost, shares	78,900	78,900
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,481,015 and $7,172,718 at December 31, 2018 and 2017, respectively )	$ 21,649,896	$ 21,096,642
Less: accumulated depreciation (amounts related to VIEs of $(965,500) and $(854,172) at December 31, 2018 and 2017, respectively	(4,897,777)	(4,589,634)
Cash and cash equivalents (amounts related to VIEs of $296,806 and $304,955 at December 31, 2018 and 2017, respectively)	543,359	434,767
Cash held in escrows	95,832	70,602
Tenant and other receivables, net (amounts related to VIEs of $15,519 and $27,057 at December 31, 2018 and 2017, respectively)	86,629	92,186
Accrued rental income, net (amounts related to VIEs of $272,466 and $242,589 at December 31, 2018 and 2017, respectively)	934,896	861,575
Deferred charges, net (amounts related to VIEs of $263,402 and $281,678 at December 31, 2018 and 2017, respectively)	678,724	679,038
Prepaid expenses and other assets (amounts related to VIEs of $26,513 and $33,666 at December 31, 2018 and 2017, respectively)	80,943	77,971
Mortgage notes payable, net (amounts related to VIEs of $2,929,326 and $2,939,183 at December 31, 2018 and 2017, respectively)	2,964,572	2,979,281
Accounts payable and accrued expenses (amounts related to VIEs of $75,786 and $106,683 at December 31, 2018 and 2017, respectively)	276,645	331,500
Other liabilities (amounts related to VIEs of $200,344 and $164,806 at December 31, 2018 and 2017, respectively)	$ 503,726	$ 443,980
Series B Cumulative Redeemable Preferred Stock / Unit [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	92,000	92,000
Series B Dividend Rate Percentage	5.25%	5.25%
Preferred stock / units, shares / units issued (in shares / units)	80,000	80,000
Series B Liquidation Preference Per Share/ Unit	$ 2,500.00	$ 2,500
Preferred stock / units, shares / units outstanding (in shares / units)	80,000	80,000
Boston Properties Limited Partnership
Redeemable Partnership Units Common Units Shares Outstanding (in units)	16,783,558	16,810,378
Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Units Outstanding (in units)	991,577	818,343
General Partners' Capital Account, Units Outstanding (in units)	1,722,336	1,719,540
Limited Partners' Capital Account, Units Outstanding (in units)	152,736,142	152,605,746
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,481,015 and $7,172,718 at December 31, 2018 and 2017, respectively )	$ 21,251,540	$ 20,685,164
Less: accumulated depreciation (amounts related to VIEs of $(965,500) and $(854,172) at December 31, 2018 and 2017, respectively	(4,800,475)	(4,496,959)
Cash and cash equivalents (amounts related to VIEs of $296,806 and $304,955 at December 31, 2018 and 2017, respectively)	543,359	434,767
Cash held in escrows	95,832	70,602
Tenant and other receivables, net (amounts related to VIEs of $15,519 and $27,057 at December 31, 2018 and 2017, respectively)	86,629	92,186
Accrued rental income, net (amounts related to VIEs of $272,466 and $242,589 at December 31, 2018 and 2017, respectively)	934,896	861,575
Deferred charges, net (amounts related to VIEs of $263,402 and $281,678 at December 31, 2018 and 2017, respectively)	678,724	679,038
Prepaid expenses and other assets (amounts related to VIEs of $26,513 and $33,666 at December 31, 2018 and 2017, respectively)	80,943	77,971
Mortgage notes payable, net (amounts related to VIEs of $2,929,326 and $2,939,183 at December 31, 2018 and 2017, respectively)	2,964,572	2,979,281
Accounts payable and accrued expenses (amounts related to VIEs of $75,786 and $106,683 at December 31, 2018 and 2017, respectively)	276,645	331,500
Other liabilities (amounts related to VIEs of $200,344 and $164,806 at December 31, 2018 and 2017, respectively)	$ 503,726	$ 443,980
Boston Properties Limited Partnership | Series B Cumulative Redeemable Preferred Stock / Unit [Member]
Series B Dividend Rate Percentage	5.25%	5.25%
Preferred stock / units, shares / units issued (in shares / units)	80,000	80,000
Series B Liquidation Preference Per Share/ Unit	$ 2,500	$ 2,500
Preferred stock / units, shares / units outstanding (in shares / units)	80,000	80,000
Variable Interest Entity, Primary Beneficiary [Member]
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,481,015 and $7,172,718 at December 31, 2018 and 2017, respectively )	$ 7,481,015	$ 7,172,718
Less: accumulated depreciation (amounts related to VIEs of $(965,500) and $(854,172) at December 31, 2018 and 2017, respectively	(965,500)	(854,172)
Cash and cash equivalents (amounts related to VIEs of $296,806 and $304,955 at December 31, 2018 and 2017, respectively)	296,806	304,955
Tenant and other receivables, net (amounts related to VIEs of $15,519 and $27,057 at December 31, 2018 and 2017, respectively)	15,519	27,057
Accrued rental income, net (amounts related to VIEs of $272,466 and $242,589 at December 31, 2018 and 2017, respectively)	272,466	242,589
Deferred charges, net (amounts related to VIEs of $263,402 and $281,678 at December 31, 2018 and 2017, respectively)	263,402	281,678
Prepaid expenses and other assets (amounts related to VIEs of $26,513 and $33,666 at December 31, 2018 and 2017, respectively)	26,513	33,666
Mortgage notes payable, net (amounts related to VIEs of $2,929,326 and $2,939,183 at December 31, 2018 and 2017, respectively)	2,929,326	2,939,183
Accounts payable and accrued expenses (amounts related to VIEs of $75,786 and $106,683 at December 31, 2018 and 2017, respectively)	75,786	106,683
Other liabilities (amounts related to VIEs of $200,344 and $164,806 at December 31, 2018 and 2017, respectively)	200,344	164,806
Variable Interest Entity, Primary Beneficiary [Member] | Boston Properties Limited Partnership
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,481,015 and $7,172,718 at December 31, 2018 and 2017, respectively )	7,481,015	7,172,718
Less: accumulated depreciation (amounts related to VIEs of $(965,500) and $(854,172) at December 31, 2018 and 2017, respectively	(965,500)	(854,172)
Cash and cash equivalents (amounts related to VIEs of $296,806 and $304,955 at December 31, 2018 and 2017, respectively)	296,806	304,955
Tenant and other receivables, net (amounts related to VIEs of $15,519 and $27,057 at December 31, 2018 and 2017, respectively)	15,519	27,057
Accrued rental income, net (amounts related to VIEs of $272,466 and $242,589 at December 31, 2018 and 2017, respectively)	272,466	242,589
Deferred charges, net (amounts related to VIEs of $263,402 and $281,678 at December 31, 2018 and 2017, respectively)	263,402	281,678
Prepaid expenses and other assets (amounts related to VIEs of $26,513 and $33,666 at December 31, 2018 and 2017, respectively)	26,513	33,666
Mortgage notes payable, net (amounts related to VIEs of $2,929,326 and $2,939,183 at December 31, 2018 and 2017, respectively)	2,929,326	2,939,183
Accounts payable and accrued expenses (amounts related to VIEs of $75,786 and $106,683 at December 31, 2018 and 2017, respectively)	75,786	106,683
Other liabilities (amounts related to VIEs of $200,344 and $164,806 at December 31, 2018 and 2017, respectively)	$ 200,344	$ 164,806