Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,278,298 and $7,172,718 at March 31, 2018 and December 31, 2017, respectively)	$ 21,316,644	$ 21,096,642
Less: accumulated depreciation (amounts related to VIEs of $(883,969) and $(854,172) at March 31, 2018 and December 31, 2017, respectively)	(4,674,838)	(4,589,634)
Total real estate	16,641,806	16,507,008
Cash and cash equivalents (amounts related to VIEs of $267,842 and $304,955 at March 31, 2018 and December 31, 2017, respectively)	294,571	434,767
Cash held in escrows (amounts related to VIEs of $6,141 and $6,135 at March 31, 2018 and December 31, 2017, respectively)	160,558	70,602
Investments in securities	29,353	29,161
Tenant and other receivables (amounts related to VIEs of $20,023 and $27,057 at March 31, 2018 and December 31, 2017, respectively)	73,401	92,186
Accrued rental income (amounts related to VIEs of $258,593 and $242,589 at March 31, 2018 and December 31, 2017, respectively)	888,907	861,575
Deferred charges, net (amounts related to VIEs of $272,475 and $281,678 at March 31, 2018 and December 31, 2017, respectively)	681,369	679,038
Prepaid expenses and other assets (amounts related to VIEs of $61,467 and $33,666 at March 31, 2018 and December 31, 2017, respectively)	147,256	77,971
Investments in unconsolidated joint ventures	666,718	619,925
Total assets	19,583,939	19,372,233
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,936,778 and $2,939,183 at March 31, 2018 and December 31, 2017, respectively)	2,974,930	2,979,281
Unsecured senior notes, net	7,249,383	7,247,330
Unsecured line of credit	115,000	45,000
Unsecured term loan	0	0
Accounts payable and accrued expenses (amounts related to VIEs of $126,300 and $106,683 at March 31, 2018 and December 31, 2017, respectively)	355,002	331,500
Dividends and distributions payable	139,218	139,040
Accrued interest payable (amounts related to VIEs of $6,897 and $6,907 at March 31, 2018 and December 31, 2017, respectively)	96,176	83,646
Other liabilities (amounts related to VIEs of $187,195 and $164,806 at March 31, 2018 and December 31, 2017, respectively)	470,140	443,980
Total liabilities	11,399,849	11,269,777
Commitments and contingencies	0	0
Equity / Capital:
Excess stock, $0.01 par value, 150,000,000 shares authorized, none issued or outstanding	0	0
Preferred stock, $.01 par value, 50,000,000 shares authorized
5.25% Series B cumulative redeemable preferred stock/unit, liquidation preference $2,500 per share/unit, 92,000 shares authorized, 80,000 shares/units issued and outstanding at March 31, 2018 and December 31, 2016	200,000	200,000
Common stock, $0.01 par value, 250,000,000 shares authorized, 154,441,203 and 154,404,186 issued and 154,362,303 and 154,325,286 outstanding at March 31, 2018 and December 31, 2017, respectively	1,544	1,543
Additional paid-in capital	6,384,147	6,377,908
Dividends in excess of earnings	(654,879)	(712,343)
Treasury common stock at cost, 78,900 shares at March 31, 2018 and December 31, 2017	(2,722)	(2,722)
Accumulated other comprehensive loss	(49,062)	(50,429)
Total stockholders’ equity attributable to Boston Properties, Inc.	5,879,028	5,813,957
Noncontrolling interests:
Common units of Boston Properties Limited Partnership	619,347	604,739
Property partnerships	1,685,715	1,683,760
Total equity / capital	8,184,090	8,102,456
Total liabilities and equity / capital	19,583,939	19,372,233
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,278,298 and $7,172,718 at March 31, 2018 and December 31, 2017, respectively)	20,908,406	20,685,164
Less: accumulated depreciation (amounts related to VIEs of $(883,969) and $(854,172) at March 31, 2018 and December 31, 2017, respectively)	(4,580,949)	(4,496,959)
Total real estate	16,327,457	16,188,205
Cash and cash equivalents (amounts related to VIEs of $267,842 and $304,955 at March 31, 2018 and December 31, 2017, respectively)	294,571	434,767
Cash held in escrows (amounts related to VIEs of $6,141 and $6,135 at March 31, 2018 and December 31, 2017, respectively)	160,558	70,602
Investments in securities	29,353	29,161
Tenant and other receivables (amounts related to VIEs of $20,023 and $27,057 at March 31, 2018 and December 31, 2017, respectively)	73,401	92,186
Accrued rental income (amounts related to VIEs of $258,593 and $242,589 at March 31, 2018 and December 31, 2017, respectively)	888,907	861,575
Deferred charges, net (amounts related to VIEs of $272,475 and $281,678 at March 31, 2018 and December 31, 2017, respectively)	681,369	679,038
Prepaid expenses and other assets (amounts related to VIEs of $61,467 and $33,666 at March 31, 2018 and December 31, 2017, respectively)	147,256	77,971
Investments in unconsolidated joint ventures	666,718	619,925
Total assets	19,269,590	19,053,430
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,936,778 and $2,939,183 at March 31, 2018 and December 31, 2017, respectively)	2,974,930	2,979,281
Unsecured senior notes, net	7,249,383	7,247,330
Unsecured line of credit	115,000	45,000
Unsecured term loan	0	0
Accounts payable and accrued expenses (amounts related to VIEs of $126,300 and $106,683 at March 31, 2018 and December 31, 2017, respectively)	355,002	331,500
Dividends and distributions payable	139,218	139,040
Accrued interest payable (amounts related to VIEs of $6,897 and $6,907 at March 31, 2018 and December 31, 2017, respectively)	96,176	83,646
Other liabilities (amounts related to VIEs of $187,195 and $164,806 at March 31, 2018 and December 31, 2017, respectively)	470,140	443,980
Total liabilities	11,399,849	11,269,777
Commitments and contingencies	0	0
Noncontrolling interest:
Redeemable partnership units—16,812,329 and 16,810,378 common units and 816,982 and 904,588 long term incentive units outstanding at redemption value at March 31, 2018 and December 31, 2017, respectively	2,196,603	2,292,263
Preferred stock, $.01 par value, 50,000,000 shares authorized
5.25% Series B cumulative redeemable preferred stock/unit, liquidation preference $2,500 per share/unit, 92,000 shares authorized, 80,000 shares/units issued and outstanding at March 31, 2018 and December 31, 2016	193,623	193,623
Noncontrolling interests:
Boston Properties Limited Partnership partners’ capital—1,719,516 and 1,719,540 general partner units and 152,602,750 and 152,605,746 limited partner units outstanding at March 31, 2018 and December 31, 2017, respectively	3,793,800	3,614,007
Noncontrolling interests in property partnerships	1,685,715	1,683,760
Total equity / capital	5,673,138	5,491,390
Total liabilities and equity / capital	$ 19,269,590	$ 19,053,430