Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,172,718 and $6,760,078 at December 31, 2017 and 2016, respectively )	$ 21,096,642	$ 20,147,263
Less: accumulated depreciation (amounts related to VIEs of $(854,172) and $(758,640) at December 31, 2017 and 2016, respectively	(4,589,634)	(4,222,235)
Total real estate	16,507,008	15,925,028
Cash and cash equivalents (amounts related to VIEs of $304,955 and $253,999 at December 31, 2017 and 2016, respectively)	434,767	356,914
Cash held in escrows (amounts related to VIEs of $6,135 and $4,955 at December 31, 2017 and 2016, respectively)	70,602	63,174
Investments in securities	29,161	23,814
Tenant and other receivables, net (amounts related to VIEs of $27,057 and $23,525 at December 31, 2017 and 2016, respectively)	92,186	92,548
Accrued rental income, net (amounts related to VIEs of $242,589 and $224,185 at December 31, 2017 and 2016, respectively)	861,575	799,138
Deferred charges, net (amounts related to VIEs of $281,678 and $290,436 at December 31, 2017 and 2016, respectively)	679,038	686,163
Prepaid expenses and other assets (amounts related to VIEs of $33,666 and $42,718 at December 31, 2017 and 2016, respectively)	77,971	129,666
Investments in unconsolidated joint ventures	619,925	775,198
Total assets	19,372,233	18,851,643
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,939,183 and $2,018,483 at December 31, 2017 and 2016, respectively)	2,979,281	2,063,087
Unsecured senior notes, net	7,247,330	7,245,953
Unsecured line of credit	45,000	0
Unsecured term loan	0	0
Mezzanine notes payable (amounts related to VIEs of $0 and $307,093 at December 31, 2017 and 2016, respectively)	0	307,093
Outside members’ notes payable (amounts related to VIEs of $0 and $180,000 at December 31, 2017 and 2016, respectively)	0	180,000
Accounts payable and accrued expenses (amounts related to VIEs of $106,683 and $110,457 at December 31, 2017 and 2016, respectively)	331,500	298,524
Dividends and distributions payable	139,040	130,308
Accrued interest payable (amounts related to VIEs of $6,907 and $162,226 at December 31, 2017 and 2016, respectively)	83,646	243,933
Other liabilities (amounts related to VIEs of $164,806 and $175,146 at December 31, 2017 and 2016, respectively)	443,980	450,821
Total liabilities	11,269,777	10,919,719
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, $0.01 par value, 50,000,000 shares authorized;
5.25% Series B cumulative redeemable preferred stock / units, liquidation preference $2,500 per share / unit, 80,000 shares / units issued and outstanding at December 31, 2016 and December 31, 2015, respectively	200,000	200,000
Common stock, $0.01 par value, 250,000,000 shares authorized,154,404,186 and 153,869,075 issued and 154,325,286 and 153,790,175 outstanding at December 31, 2017 and December 31, 2016, respectively	1,543	1,538
Additional paid-in capital	6,377,908	6,333,424
Dividends in excess of earnings	(712,343)	(693,694)
Treasury common stock at cost, 78,900 shares at December 31, 2017 and December 31, 2016	(2,722)	(2,722)
Accumulated other comprehensive loss	(50,429)	(52,251)
Total stockholders' equity attributable to Boston Properties, Inc.	5,813,957	5,786,295
Noncontrolling interests:
Common units of the Operating Partnership	604,739	614,982
Property partnerships	1,683,760	1,530,647
Total equity / capital	8,102,456	7,931,924
Total liabilities and equity / capital	19,372,233	18,851,643
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,172,718 and $6,760,078 at December 31, 2017 and 2016, respectively )	20,685,164	19,733,872
Less: accumulated depreciation (amounts related to VIEs of $(854,172) and $(758,640) at December 31, 2017 and 2016, respectively	(4,496,959)	(4,136,364)
Total real estate	16,188,205	15,597,508
Cash and cash equivalents (amounts related to VIEs of $304,955 and $253,999 at December 31, 2017 and 2016, respectively)	434,767	356,914
Cash held in escrows (amounts related to VIEs of $6,135 and $4,955 at December 31, 2017 and 2016, respectively)	70,602	63,174
Investments in securities	29,161	23,814
Tenant and other receivables, net (amounts related to VIEs of $27,057 and $23,525 at December 31, 2017 and 2016, respectively)	92,186	92,548
Accrued rental income, net (amounts related to VIEs of $242,589 and $224,185 at December 31, 2017 and 2016, respectively)	861,575	799,138
Deferred charges, net (amounts related to VIEs of $281,678 and $290,436 at December 31, 2017 and 2016, respectively)	679,038	686,163
Prepaid expenses and other assets (amounts related to VIEs of $33,666 and $42,718 at December 31, 2017 and 2016, respectively)	77,971	129,666
Investments in unconsolidated joint ventures	619,925	775,198
Total assets	19,053,430	18,524,123
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,939,183 and $2,018,483 at December 31, 2017 and 2016, respectively)	2,979,281	2,063,087
Unsecured senior notes, net	7,247,330	7,245,953
Unsecured line of credit	45,000	0
Unsecured term loan	0	0
Mezzanine notes payable (amounts related to VIEs of $0 and $307,093 at December 31, 2017 and 2016, respectively)	0	307,093
Outside members’ notes payable (amounts related to VIEs of $0 and $180,000 at December 31, 2017 and 2016, respectively)	0	180,000
Accounts payable and accrued expenses (amounts related to VIEs of $106,683 and $110,457 at December 31, 2017 and 2016, respectively)	331,500	298,524
Dividends and distributions payable	139,040	130,308
Accrued interest payable (amounts related to VIEs of $6,907 and $162,226 at December 31, 2017 and 2016, respectively)	83,646	243,933
Other liabilities (amounts related to VIEs of $164,806 and $175,146 at December 31, 2017 and 2016, respectively)	443,980	450,821
Total liabilities	11,269,777	10,919,719
Commitments and contingencies	0	0
Noncontrolling interest:
Redeemable partnership units—16,810,378 and 17,079,511 common units and 818,343 and 904,588 long term incentive units outstanding at redemption value at December 31, 2017 and December 31, 2016, respectively	2,292,263	2,262,040
Preferred stock, $0.01 par value, 50,000,000 shares authorized;
5.25% Series B cumulative redeemable preferred stock / units, liquidation preference $2,500 per share / unit, 80,000 shares / units issued and outstanding at December 31, 2016 and December 31, 2015, respectively	193,623	193,623
Boston Properties Limited Partnership partners’ capital—1,719,540 and 1,717,743 general partner units and 152,605,746 and 152,072,432 limited partner units outstanding at December 31, 2017 and December 31, 2016, respectively	3,614,007	3,618,094
Accumulated other comprehensive loss	(58,825)	(60,853)
Noncontrolling interests:
Property partnerships	1,683,760	1,530,647
Total equity / capital	5,491,390	5,342,364
Total liabilities and equity / capital	$ 19,053,430	$ 18,524,123