Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,426,998 and $7,172,718 at September 30, 2018 and December 31, 2017, respectively)	$ 21,687,639	$ 21,096,642
Less: accumulated depreciation (amounts related to VIEs of $(942,678) and $(854,172) at September 30, 2018 and December 31, 2017, respectively)	(4,838,496)	(4,589,634)
Total real estate	16,849,143	16,507,008
Cash and cash equivalents (amounts related to VIEs of $284,053 and $304,955 at September 30, 2018 and December 31, 2017, respectively)	322,502	434,767
Cash held in escrows (amounts related to VIEs of $6,118 and $6,135 at September 30, 2018 and December 31, 2017, respectively)	101,282	70,602
Investments in securities	31,376	29,161
Tenant and other receivables (amounts related to VIEs of $42,193 and $27,057 at September 30, 2018 and December 31, 2017, respectively)	98,502	92,186
Related party note receivable	80,000	0
Accrued rental income (amounts related to VIEs of $269,794 and $242,589 at September 30, 2018 and December 31, 2017, respectively)	926,274	861,575
Deferred charges, net (amounts related to VIEs of $261,951 and $281,678 at September 30, 2018 and December 31, 2017, respectively)	669,545	679,038
Prepaid expenses and other assets (amounts related to VIEs of $62,325 and $33,666 at September 30, 2018 and December 31, 2017, respectively)	133,443	77,971
Investments in unconsolidated joint ventures	925,431	619,925
Total assets	20,137,498	19,372,233
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,931,852 and $2,939,183 at September 30, 2018 and December 31, 2017, respectively)	2,967,548	2,979,281
Unsecured senior notes, net	7,253,786	7,247,330
Unsecured line of credit	170,000	45,000
Unsecured term loan, net	498,368	0
Accounts payable and accrued expenses (amounts related to VIEs of $78,893 and $106,683 at September 30, 2018 and December 31, 2017, respectively)	315,462	331,500
Dividends and distributions payable	165,118	139,040
Accrued interest payable (amounts related to VIEs of $6,659 and $6,907 at September 30, 2018 and December 31, 2017, respectively)	92,809	83,646
Other liabilities (amounts related to VIEs of $200,306 and $164,806 at September 30, 2018 and December 31, 2017, respectively)	468,433	443,980
Total liabilities	11,931,524	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 September 30, 2018 and December 31, 2017	200,000	200,000
Common stock, $0.01 par value, 250,000,000 shares authorized, 154,519,139 and 154,404,186 issued and 154,440,239 and 154,325,286 outstanding at September 30, 2018 and December 31, 2017, respectively	1,544	1,543
Additional paid-in capital	6,400,193	6,377,908
Dividends in excess of earnings	(677,312)	(712,343)
Treasury common stock at cost, 78,900 shares at September 30, 2018 and December 31, 2017	(2,722)	(2,722)
Accumulated other comprehensive loss	(45,137)	(50,429)
Total stockholders’ equity attributable to Boston Properties, Inc.	5,876,566	5,813,957
Noncontrolling interests:
Common units of Boston Properties Limited Partnership	618,380	604,739
Property partnerships	1,711,028	1,683,760
Total equity / capital	8,205,974	8,102,456
Total liabilities and equity / capital	20,137,498	19,372,233
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,426,998 and $7,172,718 at September 30, 2018 and December 31, 2017, respectively)	21,281,726	20,685,164
Less: accumulated depreciation (amounts related to VIEs of $(942,678) and $(854,172) at September 30, 2018 and December 31, 2017, respectively)	(4,741,280)	(4,496,959)
Total real estate	16,540,446	16,188,205
Cash and cash equivalents (amounts related to VIEs of $284,053 and $304,955 at September 30, 2018 and December 31, 2017, respectively)	322,502	434,767
Cash held in escrows (amounts related to VIEs of $6,118 and $6,135 at September 30, 2018 and December 31, 2017, respectively)	101,282	70,602
Investments in securities	31,376	29,161
Tenant and other receivables (amounts related to VIEs of $42,193 and $27,057 at September 30, 2018 and December 31, 2017, respectively)	98,502	92,186
Related party note receivable	80,000	0
Accrued rental income (amounts related to VIEs of $269,794 and $242,589 at September 30, 2018 and December 31, 2017, respectively)	926,274	861,575
Deferred charges, net (amounts related to VIEs of $261,951 and $281,678 at September 30, 2018 and December 31, 2017, respectively)	669,545	679,038
Prepaid expenses and other assets (amounts related to VIEs of $62,325 and $33,666 at September 30, 2018 and December 31, 2017, respectively)	133,443	77,971
Investments in unconsolidated joint ventures	925,431	619,925
Total assets	19,828,801	19,053,430
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,931,852 and $2,939,183 at September 30, 2018 and December 31, 2017, respectively)	2,967,548	2,979,281
Unsecured senior notes, net	7,253,786	7,247,330
Unsecured line of credit	170,000	45,000
Unsecured term loan, net	498,368	0
Accounts payable and accrued expenses (amounts related to VIEs of $78,893 and $106,683 at September 30, 2018 and December 31, 2017, respectively)	315,462	331,500
Dividends and distributions payable	165,118	139,040
Accrued interest payable (amounts related to VIEs of $6,659 and $6,907 at September 30, 2018 and December 31, 2017, respectively)	92,809	83,646
Other liabilities (amounts related to VIEs of $200,306 and $164,806 at September 30, 2018 and December 31, 2017, respectively)	468,433	443,980
Total liabilities	11,931,524	11,269,777
Commitments and contingencies	0	0
Noncontrolling interest:
Redeemable partnership units—16,804,929 and 16,810,378 common units and 992,321 and 818,343 long term incentive units outstanding at redemption value at September 30, 2018 and December 31, 2017, respectively	2,190,664	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 September 30, 2018 and December 31, 2017	193,623	193,623
Noncontrolling interests:
Boston Properties Limited Partnership partners’ capital—1,722,375 and 1,719,540 general partner units and 152,717,864 and 152,605,746 limited partner units outstanding at September 30, 2018 and December 31, 2017, respectively	3,801,962	3,614,007
Noncontrolling interests in property partnerships	1,711,028	1,683,760
Total equity / capital	5,706,613	5,491,390
Total liabilities and equity / capital	$ 19,828,801	$ 19,053,430