Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,462,315 and $7,481,015 at September 30, 2019 and December 31, 2018, respectively)	$ 22,288,800	$ 21,649,896
Right of use assets - finance leases (amount related to VIEs of $21,000 at September 30, 2019)	237,394
Right of use assets - operating leases	149,231
Less: accumulated depreciation (amounts related to VIEs of $(1,027,583) and $(965,500) at September 30, 2019 and December 31, 2018, respectively)	(5,164,353)	(4,897,777)
Total real estate	17,511,072	16,752,119
Cash and cash equivalents (amounts related to VIEs of $280,253 and $296,806 at September 30, 2019 and December 31, 2018, respectively)	751,210	543,359
Cash held in escrows	53,555	95,832
Investments in securities	34,375	28,198
Tenant and other receivables (amounts related to VIEs of $25,259 and $15,519 at September 30, 2019 and December 31, 2018, respectively)	102,155	86,629
Note receivable	19,844	19,468
Related party note receivable	80,000	80,000
Accrued rental income (amounts related to VIEs of $292,668 and $272,466 at September 30, 2019 and December 31, 2018, respectively)	1,003,033	934,896
Deferred charges, net (amounts related to VIEs of $218,634 and $263,402 at September 30, 2019 and December 31, 2018, respectively)	689,768	678,724
Prepaid expenses and other assets (amounts related to VIEs of $58,057 and $26,513 at September 30, 2019 and December 31, 2018, respectively)	110,308	80,943
Investments in unconsolidated joint ventures	933,255	956,309
Total assets	21,288,575	20,256,477
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,921,499 and $2,929,326 at September 30, 2019 and December 31, 2018, respectively)	2,952,006	2,964,572
Unsecured senior notes, net	8,387,913	7,544,697
Unsecured line of credit	0	0
Unsecured term loan, net	498,819	498,488
Lease liabilities - finance leases (amount related to VIEs of $20,148 at September 30, 2019)	221,029
Lease liabilities - operating leases	199,755
Accounts payable and accrued expenses (amounts related to VIEs of $44,013 and $75,786 at September 30, 2019 and December 31, 2018, respectively)	421,269	276,645
Dividends and distributions payable	165,421	165,114
Accrued interest payable	83,177	89,267
Other liabilities (amounts related to VIEs of $129,185 and $200,344 at September 30, 2019 and December 31, 2018, respectively)	356,338	503,726
Total liabilities	13,285,727	12,042,509
Commitments and contingencies	0	0
Redeemable deferred stock units—54,610 units outstanding at redemption value at September 30, 2019	7,081	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, 2019 and December 31, 2018	200,000	200,000
Common stock, $0.01 par value, 250,000,000 shares authorized, 154,650,973 and 154,537,378 issued and 154,572,073 and 154,458,478 outstanding at September 30, 2019 and December 31, 2018, respectively	1,546	1,545
Additional paid-in capital	6,274,792	6,407,623
Dividends in excess of earnings	(749,666)	(675,534)
Treasury common stock at cost, 78,900 shares at September 30, 2019 and December 31, 2018	(2,722)	(2,722)
Accumulated other comprehensive loss	(51,996)	(47,741)
Total stockholders’ equity attributable to Boston Properties, Inc.	5,671,954	5,883,171
Noncontrolling interests:
Common units of Boston Properties Limited Partnership	603,690	619,352
Property partnerships	1,720,123	1,711,445
Total equity	7,995,767	8,213,968
Total liabilities and equity / capital	21,288,575	20,256,477
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,462,315 and $7,481,015 at September 30, 2019 and December 31, 2018, respectively)	21,893,001	21,251,540
Right of use assets - finance leases (amount related to VIEs of $21,000 at September 30, 2019)	237,394
Right of use assets - operating leases	149,231
Less: accumulated depreciation (amounts related to VIEs of $(1,027,583) and $(965,500) at September 30, 2019 and December 31, 2018, respectively)	(5,061,727)	(4,800,475)
Total real estate	17,217,899	16,451,065
Cash and cash equivalents (amounts related to VIEs of $280,253 and $296,806 at September 30, 2019 and December 31, 2018, respectively)	751,210	543,359
Cash held in escrows	53,555	95,832
Investments in securities	34,375	28,198
Tenant and other receivables (amounts related to VIEs of $25,259 and $15,519 at September 30, 2019 and December 31, 2018, respectively)	102,155	86,629
Note receivable	19,844	19,468
Related party note receivable	80,000	80,000
Accrued rental income (amounts related to VIEs of $292,668 and $272,466 at September 30, 2019 and December 31, 2018, respectively)	1,003,033	934,896
Deferred charges, net (amounts related to VIEs of $218,634 and $263,402 at September 30, 2019 and December 31, 2018, respectively)	689,768	678,724
Prepaid expenses and other assets (amounts related to VIEs of $58,057 and $26,513 at September 30, 2019 and December 31, 2018, respectively)	110,308	80,943
Investments in unconsolidated joint ventures	933,255	956,309
Total assets	20,995,402	19,955,423
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $2,921,499 and $2,929,326 at September 30, 2019 and December 31, 2018, respectively)	2,952,006	2,964,572
Unsecured senior notes, net	8,387,913	7,544,697
Unsecured line of credit	0	0
Unsecured term loan, net	498,819	498,488
Lease liabilities - finance leases (amount related to VIEs of $20,148 at September 30, 2019)	221,029
Lease liabilities - operating leases	199,755
Accounts payable and accrued expenses (amounts related to VIEs of $44,013 and $75,786 at September 30, 2019 and December 31, 2018, respectively)	421,269	276,645
Dividends and distributions payable	165,421	165,114
Accrued interest payable	83,177	89,267
Other liabilities (amounts related to VIEs of $129,185 and $200,344 at September 30, 2019 and December 31, 2018, respectively)	356,338	503,726
Total liabilities	13,285,727	12,042,509
Commitments and contingencies	0	0
Redeemable deferred stock units—54,610 units outstanding at redemption value at September 30, 2019	7,081	0
Noncontrolling interest:
Redeemable partnership units—16,821,620 and 16,783,558 common units and 1,189,117 and 991,577 long term incentive units outstanding at redemption value at September 30, 2019 and December 31, 2018, respectively	2,335,272	2,000,591
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, 2019 and December 31, 2018	193,623	193,623
Boston Properties Limited Partnership partners’ capital — 1,725,828 and 1,722,336 general partner units and 152,846,245 and 152,736,142 limited partner units outstanding at September 30, 2019 and December 31, 2018, respectively	3,505,572	4,054,996
Accumulated other comprehensive loss	(51,996)	(47,741)
Noncontrolling interests:
Total partners’ capital	3,647,199	4,200,878
Noncontrolling interests in property partnerships	1,720,123	1,711,445
Total equity / capital	5,367,322	5,912,323
Total liabilities and equity / capital	$ 20,995,402	$ 19,955,423