Consolidated Balance Sheets - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,902,389 and $6,789,029 at September 30, 2023 and December 31, 2022, respectively)		$ 26,031,390	$ 25,389,663
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2023 and December 31, 2022, respectively)		237,532	237,510
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)	[1]	322,790	167,351
Less: accumulated depreciation (amounts related to VIEs of $(1,463,949) and $(1,381,401) at September 30, 2023 and December 31, 2022, respectively)		(6,723,616)	(6,298,082)
Total real estate		19,868,096	19,496,442
Cash and cash equivalents (amounts related to VIEs of $240,039 and $259,658 at September 30, 2023 and December 31, 2022, respectively)		882,647	690,333
Cash held in escrows		47,741	46,479
Investments in securities		32,809	32,277
Tenant and other receivables, net (amounts related to VIEs of $36,758 and $16,521 at September 30, 2023 and December 31, 2022, respectively)		123,138	81,389
Sales-type lease receivable, net		13,475	12,811
Accrued rental income, net (amounts related to VIEs of $393,227 and $367,138 at September 30, 2023 and December 31, 2022, respectively)		1,331,796	1,276,580
Deferred charges, net (amounts related to VIEs of $171,998 and $176,597 at September 30, 2023 and December 31, 2022, respectively)		692,386	733,282
Prepaid expenses and other assets (amounts related to VIEs of $46,473 and $11,647 at September 30, 2023 and December 31, 2022, respectively)		121,431	43,589
Investments in unconsolidated joint ventures		1,536,822	1,715,911
Total assets		24,739,148	24,207,669
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,275,974 and $3,272,368 at September 30, 2023 and December 31, 2022, respectively)		3,275,974	3,272,368
Unsecured senior notes, net		10,488,568	10,237,968
Unsecured line of credit		0	0
Unsecured term loan		1,197,173	730,000
Lease liabilities - finance leases (amounts related to VIEs of $20,710 and $20,604 at September 30, 2023 and December 31, 2022, respectively)		253,178	249,335
Lease liabilities - operating leases (amounts related to VIEs of $136,332 and $0 at September 30, 2023 and December 31, 2022, respectively)		341,299	204,686
Accounts payable and accrued expenses (amounts related to VIEs of $43,696 and $29,466 at September 30, 2023 and December 31, 2022, respectively)		462,240	417,545
Dividends and distributions payable		171,916	170,643
Accrued interest payable		128,422	103,774
Other liabilities (amounts related to VIEs of $106,566 and $114,232 at September 30, 2023 and December 31, 2022, respectively)		380,014	450,918
Total liabilities		16,698,784	15,837,237
Redeemable deferred stock units— 114,124 and 97,853 units outstanding at redemption value at September 30, 2023 and December 31, 2022, respectively		$ 6,788	$ 6,613
Excess stock, shares outstanding		0	0
Excess stock, shares issued		0	0
Preferred stock / units, shares / units issued (in shares / units)		0	0
Preferred stock / units, shares / units outstanding (in shares / units)		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, none issued or outstanding		0	0
Common stock, $0.01 par value, 250,000,000 shares authorized, 157,018,080 and 156,836,767 issued and 156,939,180 and 156,757,867 outstanding at September 30, 2023 and December 31, 2022, respectively		1,569	1,568
Additional paid-in capital		6,568,645	6,539,147
Dividends in excess of earnings		$ (782,275)	$ (391,356)
Treasury common stock at cost, shares		78,900	78,900
Treasury common stock at cost, 78,900 shares at September 30, 2023 and December 31, 2022		$ (2,722)	$ (2,722)
Accumulated other comprehensive income (loss)		2,866	(13,718)
Total stockholders' equity attributable to Boston Properties, Inc.		5,788,083	6,132,919
Noncontrolling interests:
Common units of the Operating Partnership		656,587	683,583
Property partnerships		1,588,906	1,547,317
Total equity / capital		8,033,576	8,363,819
Total liabilities and equity / capital		24,739,148	24,207,669
Related Party
ASSETS
Related party note receivable, net		88,807	78,576
Variable Interest Entity, Primary Beneficiary [Member]
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,902,389 and $6,789,029 at September 30, 2023 and December 31, 2022, respectively)		6,902,389	6,789,029
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2023 and December 31, 2022, respectively)		21,000	21,000
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)		156,940	0
Less: accumulated depreciation (amounts related to VIEs of $(1,463,949) and $(1,381,401) at September 30, 2023 and December 31, 2022, respectively)		(1,463,949)	(1,381,401)
Cash and cash equivalents (amounts related to VIEs of $240,039 and $259,658 at September 30, 2023 and December 31, 2022, respectively)		240,039	259,658
Tenant and other receivables, net (amounts related to VIEs of $36,758 and $16,521 at September 30, 2023 and December 31, 2022, respectively)		36,758	16,521
Accrued rental income, net (amounts related to VIEs of $393,227 and $367,138 at September 30, 2023 and December 31, 2022, respectively)		393,227	367,138
Deferred charges, net (amounts related to VIEs of $171,998 and $176,597 at September 30, 2023 and December 31, 2022, respectively)		171,998	176,597
Prepaid expenses and other assets (amounts related to VIEs of $46,473 and $11,647 at September 30, 2023 and December 31, 2022, respectively)		46,473	11,647
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,275,974 and $3,272,368 at September 30, 2023 and December 31, 2022, respectively)		3,275,974	3,272,368
Lease liabilities - finance leases (amounts related to VIEs of $20,710 and $20,604 at September 30, 2023 and December 31, 2022, respectively)		20,710	20,604
Lease liabilities - operating leases (amounts related to VIEs of $136,332 and $0 at September 30, 2023 and December 31, 2022, respectively)		136,332	0
Accounts payable and accrued expenses (amounts related to VIEs of $43,696 and $29,466 at September 30, 2023 and December 31, 2022, respectively)		43,696	29,466
Other liabilities (amounts related to VIEs of $106,566 and $114,232 at September 30, 2023 and December 31, 2022, respectively)		106,566	114,232
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,902,389 and $6,789,029 at September 30, 2023 and December 31, 2022, respectively)		25,665,125	25,022,149
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2023 and December 31, 2022, respectively)		237,532	237,510
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)	[1]	322,790	167,351
Less: accumulated depreciation (amounts related to VIEs of $(1,463,949) and $(1,381,401) at September 30, 2023 and December 31, 2022, respectively)		(6,601,957)	(6,180,474)
Total real estate		19,623,490	19,246,536
Cash and cash equivalents (amounts related to VIEs of $240,039 and $259,658 at September 30, 2023 and December 31, 2022, respectively)		882,647	690,333
Cash held in escrows		47,741	46,479
Investments in securities		32,809	32,277
Tenant and other receivables, net (amounts related to VIEs of $36,758 and $16,521 at September 30, 2023 and December 31, 2022, respectively)		123,138	81,389
Sales-type lease receivable, net		13,475	12,811
Accrued rental income, net (amounts related to VIEs of $393,227 and $367,138 at September 30, 2023 and December 31, 2022, respectively)		1,331,796	1,276,580
Deferred charges, net (amounts related to VIEs of $171,998 and $176,597 at September 30, 2023 and December 31, 2022, respectively)		692,386	733,282
Prepaid expenses and other assets (amounts related to VIEs of $46,473 and $11,647 at September 30, 2023 and December 31, 2022, respectively)		121,431	43,589
Investments in unconsolidated joint ventures		1,536,822	1,715,911
Total assets		24,494,542	23,957,763
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,275,974 and $3,272,368 at September 30, 2023 and December 31, 2022, respectively)		3,275,974	3,272,368
Unsecured senior notes, net		10,488,568	10,237,968
Unsecured line of credit		0	0
Unsecured term loan		1,197,173	730,000
Lease liabilities - finance leases (amounts related to VIEs of $20,710 and $20,604 at September 30, 2023 and December 31, 2022, respectively)		253,178	249,335
Lease liabilities - operating leases (amounts related to VIEs of $136,332 and $0 at September 30, 2023 and December 31, 2022, respectively)		341,299	204,686
Accounts payable and accrued expenses (amounts related to VIEs of $43,696 and $29,466 at September 30, 2023 and December 31, 2022, respectively)		462,240	417,545
Dividends and distributions payable		171,916	170,643
Accrued interest payable		128,422	103,774
Other liabilities (amounts related to VIEs of $106,566 and $114,232 at September 30, 2023 and December 31, 2022, respectively)		380,014	450,918
Total liabilities		16,698,784	15,837,237
Redeemable deferred stock units— 114,124 and 97,853 units outstanding at redemption value at September 30, 2023 and December 31, 2022, respectively		6,788	6,613
Noncontrolling interest:
Redeemable partnership units— 16,509,597 and 16,531,172 common units and 2,072,732 and 1,679,175 long term incentive units outstanding at redemption value at September 30, 2023 and December 31, 2022, respectively		1,160,753	1,280,886
Equity / Capital:
Boston Properties Limited Partnership partners’ capital— 1,755,215 and 1,749,682 general partner units and 155,183,965 and 155,008,185 limited partner units outstanding at September 30, 2023 and December 31, 2022, respectively		5,036,445	5,299,428
Accumulated other comprehensive income (loss)		2,866	(13,718)
Total partners’ capital		5,039,311	5,285,710
Noncontrolling interests in property partnerships		1,588,906	1,547,317
Noncontrolling interests:
Total equity / capital		6,628,217	6,833,027
Total liabilities and equity / capital		24,494,542	23,957,763
Boston Properties Limited Partnership | Related Party
ASSETS
Related party note receivable, net		88,807	78,576
Boston Properties Limited Partnership | Variable Interest Entity, Primary Beneficiary [Member]
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,902,389 and $6,789,029 at September 30, 2023 and December 31, 2022, respectively)		6,902,389	6,789,029
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2023 and December 31, 2022, respectively)		21,000	21,000
Right of use assets - operating leases (amounts related to VIEs of $156,940 and $0 at September 30, 2023 and December 31, 2022, respectively)		156,940	0
Less: accumulated depreciation (amounts related to VIEs of $(1,463,949) and $(1,381,401) at September 30, 2023 and December 31, 2022, respectively)		(1,463,949)	(1,381,401)
Cash and cash equivalents (amounts related to VIEs of $240,039 and $259,658 at September 30, 2023 and December 31, 2022, respectively)		240,039	259,658
Tenant and other receivables, net (amounts related to VIEs of $36,758 and $16,521 at September 30, 2023 and December 31, 2022, respectively)		36,758	16,521
Accrued rental income, net (amounts related to VIEs of $393,227 and $367,138 at September 30, 2023 and December 31, 2022, respectively)		393,227	367,138
Deferred charges, net (amounts related to VIEs of $171,998 and $176,597 at September 30, 2023 and December 31, 2022, respectively)		171,998	176,597
Prepaid expenses and other assets (amounts related to VIEs of $46,473 and $11,647 at September 30, 2023 and December 31, 2022, respectively)		46,473	11,647
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,275,974 and $3,272,368 at September 30, 2023 and December 31, 2022, respectively)		3,275,974	3,272,368
Lease liabilities - finance leases (amounts related to VIEs of $20,710 and $20,604 at September 30, 2023 and December 31, 2022, respectively)		20,710	20,604
Lease liabilities - operating leases (amounts related to VIEs of $136,332 and $0 at September 30, 2023 and December 31, 2022, respectively)		136,332	0
Accounts payable and accrued expenses (amounts related to VIEs of $43,696 and $29,466 at September 30, 2023 and December 31, 2022, respectively)		43,696	29,466
Other liabilities (amounts related to VIEs of $106,566 and $114,232 at September 30, 2023 and December 31, 2022, respectively)		$ 106,566	$ 114,232

[1] See Note 4.