Boston Properties (BXP) 10-Q 3 May 23 2023 Q1 Quarterly report Financial data

Cover

Cover - $ / shares	3 Months Ended
	Mar. 31, 2023	Apr. 28, 2023
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	1-13087
Entity Registrant Name	BOSTON PROPERTIES, INC.
Entity Central Index Key	0001037540
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2473675
Entity Address, Address Line One	Prudential Center, 800 Boylston Street, Suite 1900
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199-8103
City Area Code	617
Local Phone Number	236-3300
Title of 12(b) Security	Common Stock, par value $0.01 per share
Entity Listing, Par Value Per Share	$ 0.01
Trading Symbol	BXP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		156,835,488
Boston Properties Limited Partnership
Entity Information [Line Items]
Document Type	10-Q
Document Period End Date	Mar. 31, 2023
Entity File Number	0-50209
Entity Registrant Name	BOSTON PROPERTIES LIMITED PARTNERSHIP
Entity Central Index Key	0001043121
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3372948
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,832,119 and $6,789,029 at March 31, 2023 and December 31, 2022, respectively)	$ 25,559,720	$ 25,389,663
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at March 31, 2023 and December 31, 2022, respectively)	237,503	237,510
Right of use assets - operating leases	166,699	167,351
Less: accumulated depreciation (amounts related to VIEs of $(1,405,167) and $(1,381,401) at March 31, 2023 and December 31, 2022, respectively)	(6,424,547)	(6,298,082)
Total real estate	19,539,375	19,496,442
Cash and cash equivalents (amounts related to VIEs of $233,981 and $259,658 at March 31, 2023 and December 31, 2022, respectively)	918,952	690,333
Cash held in escrows	45,330	46,479
Investments in securities	32,099	32,277
Tenant and other receivables, net (amounts related to VIEs of $13,108 and $16,521 at March 31, 2023 and December 31, 2022, respectively)	85,603	81,389
Related party note receivable, net	78,544	78,576
Sales-type lease receivable, net	13,028	12,811
Accrued rental income, net (amounts related to VIEs of $375,008 and $367,138 at March 31, 2023 and December 31, 2022, respectively)	1,297,767	1,276,580
Deferred charges, net (amounts related to VIEs of $172,077 and $176,597 at March 31, 2023 and December 31, 2022, respectively)	720,174	733,282
Prepaid expenses and other assets (amounts related to VIEs of $40,737 and $11,647 at March 31, 2023 and December 31, 2022, respectively)	141,933	43,589
Investments in unconsolidated joint ventures	1,752,617	1,715,911
Total assets	24,625,422	24,207,669
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,273,553 and $3,272,368 at March 31, 2023 and December 31, 2022, respectively)	3,273,553	3,272,368
Unsecured senior notes, net	10,240,967	10,237,968
Unsecured line of credit	0	0
Unsecured term loan	1,194,916	730,000
Lease liabilities - finance leases (amounts related to VIEs of $20,641 and $20,604 at March 31, 2023 and December 31, 2022, respectively)	250,567	249,335
Lease liabilities - operating leases	204,435	204,686
Accounts payable and accrued expenses (amounts related to VIEs of $37,595 and $29,466 at March 31, 2023 and December 31, 2022, respectively)	397,798	417,545
Dividends and distributions payable	171,427	170,643
Accrued interest payable	114,400	103,774
Other liabilities (amounts related to VIEs of $114,694 and $114,232 at March 31, 2023 and December 31, 2022, respectively)	465,276	450,918
Total liabilities	16,313,339	15,837,237
Redeemable deferred stock units— 103,454 and 97,853 units outstanding at redemption value at March 31, 2023 and December 31, 2022, respectively	$ 5,599	$ 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, 156,908,693 and 156,836,767 issued and 156,829,793 and 156,757,867 outstanding at March 31, 2023 and December 31, 2022, respectively	1,568	1,568
Additional paid-in capital	6,549,314	6,539,147
Dividends in excess of earnings	(467,159)	(391,356)
Treasury common stock at cost, 78,900 shares at March 31, 2023 and December 31, 2022	(2,722)	(2,722)
Accumulated other comprehensive loss	(18,214)	(13,718)
Total stockholders' equity attributable to Boston Properties, Inc.	6,062,787	6,132,919
Noncontrolling interests:
Common units of the Operating Partnership	691,627	683,583
Property partnerships	1,552,070	1,547,317
Total equity / capital	8,306,484	8,363,819
Total liabilities and equity / capital	24,625,422	24,207,669
Boston Properties Limited Partnership
ASSETS
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,832,119 and $6,789,029 at March 31, 2023 and December 31, 2022, respectively)	25,193,455	25,022,149
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at March 31, 2023 and December 31, 2022, respectively)	237,503	237,510
Right of use assets - operating leases	166,699	167,351
Less: accumulated depreciation (amounts related to VIEs of $(1,405,167) and $(1,381,401) at March 31, 2023 and December 31, 2022, respectively)	(6,306,326)	(6,180,474)
Total real estate	19,291,331	19,246,536
Cash and cash equivalents (amounts related to VIEs of $233,981 and $259,658 at March 31, 2023 and December 31, 2022, respectively)	918,952	690,333
Cash held in escrows	45,330	46,479
Investments in securities	32,099	32,277
Tenant and other receivables, net (amounts related to VIEs of $13,108 and $16,521 at March 31, 2023 and December 31, 2022, respectively)	85,603	81,389
Related party note receivable, net	78,544	78,576
Sales-type lease receivable, net	13,028	12,811
Accrued rental income, net (amounts related to VIEs of $375,008 and $367,138 at March 31, 2023 and December 31, 2022, respectively)	1,297,767	1,276,580
Deferred charges, net (amounts related to VIEs of $172,077 and $176,597 at March 31, 2023 and December 31, 2022, respectively)	720,174	733,282
Prepaid expenses and other assets (amounts related to VIEs of $40,737 and $11,647 at March 31, 2023 and December 31, 2022, respectively)	141,933	43,589
Investments in unconsolidated joint ventures	1,752,617	1,715,911
Total assets	24,377,378	23,957,763
Liabilities:
Mortgage notes payable, net (amounts related to VIEs of $3,273,553 and $3,272,368 at March 31, 2023 and December 31, 2022, respectively)	3,273,553	3,272,368
Unsecured senior notes, net	10,240,967	10,237,968
Unsecured line of credit	0	0
Unsecured term loan	1,194,916	730,000
Lease liabilities - finance leases (amounts related to VIEs of $20,641 and $20,604 at March 31, 2023 and December 31, 2022, respectively)	250,567	249,335
Lease liabilities - operating leases	204,435	204,686
Accounts payable and accrued expenses (amounts related to VIEs of $37,595 and $29,466 at March 31, 2023 and December 31, 2022, respectively)	397,798	417,545
Dividends and distributions payable	171,427	170,643
Accrued interest payable	114,400	103,774
Other liabilities (amounts related to VIEs of $114,694 and $114,232 at March 31, 2023 and December 31, 2022, respectively)	465,276	450,918
Total liabilities	16,313,339	15,837,237
Redeemable deferred stock units— 103,454 and 97,853 units outstanding at redemption value at March 31, 2023 and December 31, 2022, respectively	5,599	6,613
Noncontrolling interest:
Redeemable partnership units— 16,527,638 and 16,531,172 common units and 2,131,785 and 1,679,175 long term incentive units outstanding at redemption value at March 31, 2023 and December 31, 2022, respectively	1,074,648	1,280,886
Equity / Capital:
Boston Properties Limited Partnership partners’ capital— 1,754,892 and 1,749,682 general partner units and 155,074,901 and 155,008,185 limited partner units outstanding at March 31, 2023 and December 31, 2022, respectively	5,449,936	5,299,428
Accumulated other comprehensive loss	(18,214)	(13,718)
Total partners’ capital	5,431,722	5,285,710
Noncontrolling interests in property partnerships	1,552,070	1,547,317
Noncontrolling interests:
Total equity / capital	6,983,792	6,833,027
Total liabilities and equity / capital	$ 24,377,378	$ 23,957,763

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,832,119 and $6,789,029 at March 31, 2023 and December 31, 2022, respectively)	$ 25,559,720	$ 25,389,663
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at March 31, 2023 and December 31, 2022, respectively)	237,503	237,510
Less: accumulated depreciation (amounts related to VIEs of $(1,405,167) and $(1,381,401) at March 31, 2023 and December 31, 2022, respectively)	(6,424,547)	(6,298,082)
Cash and cash equivalents (amounts related to VIEs of $233,981 and $259,658 at March 31, 2023 and December 31, 2022, respectively)	918,952	690,333
Tenant and other receivables, net (amounts related to VIEs of $13,108 and $16,521 at March 31, 2023 and December 31, 2022, respectively)	85,603	81,389
Accrued rental income, net (amounts related to VIEs of $375,008 and $367,138 at March 31, 2023 and December 31, 2022, respectively)	1,297,767	1,276,580
Deferred charges, net (amounts related to VIEs of $172,077 and $176,597 at March 31, 2023 and December 31, 2022, respectively)	720,174	733,282
Prepaid expenses and other assets (amounts related to VIEs of $40,737 and $11,647 at March 31, 2023 and December 31, 2022, respectively)	141,933	43,589
Mortgage notes payable, net (amounts related to VIEs of $3,273,553 and $3,272,368 at March 31, 2023 and December 31, 2022, respectively)	3,273,553	3,272,368
Lease liabilities - finance leases (amounts related to VIEs of $20,641 and $20,604 at March 31, 2023 and December 31, 2022, respectively)	250,567	249,335
Accounts payable and accrued expenses (amounts related to VIEs of $37,595 and $29,466 at March 31, 2023 and December 31, 2022, respectively)	397,798	417,545
Other liabilities (amounts related to VIEs of $114,694 and $114,232 at March 31, 2023 and December 31, 2022, respectively)	$ 465,276	$ 450,918
Reedemable deferred stock units, units	103,454	97,853
Limited Partners' Capital Account, Units Outstanding (in units)	155,074,901
General Partners' Capital Account, Units Outstanding (in units)	1,754,892
Excess stock, par value	$ 0.01	$ 0.01
Excess stock, shares authorized	150,000,000	150,000,000
Excess stock, shares outstanding	0	0
Excess stock, shares issued	0	0
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock / units, shares / units issued (in shares / units)	0	0
Preferred stock / units, shares / units outstanding (in shares / units)	0	0
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	156,908,693	156,836,767
Common Stock, Shares, Outstanding	156,829,793	156,757,867
Treasury common stock at cost, shares	78,900	78,900
Boston Properties Limited Partnership
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,832,119 and $6,789,029 at March 31, 2023 and December 31, 2022, respectively)	$ 25,193,455	$ 25,022,149
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at March 31, 2023 and December 31, 2022, respectively)	237,503	237,510
Less: accumulated depreciation (amounts related to VIEs of $(1,405,167) and $(1,381,401) at March 31, 2023 and December 31, 2022, respectively)	(6,306,326)	(6,180,474)
Cash and cash equivalents (amounts related to VIEs of $233,981 and $259,658 at March 31, 2023 and December 31, 2022, respectively)	918,952	690,333
Tenant and other receivables, net (amounts related to VIEs of $13,108 and $16,521 at March 31, 2023 and December 31, 2022, respectively)	85,603	81,389
Accrued rental income, net (amounts related to VIEs of $375,008 and $367,138 at March 31, 2023 and December 31, 2022, respectively)	1,297,767	1,276,580
Deferred charges, net (amounts related to VIEs of $172,077 and $176,597 at March 31, 2023 and December 31, 2022, respectively)	720,174	733,282
Prepaid expenses and other assets (amounts related to VIEs of $40,737 and $11,647 at March 31, 2023 and December 31, 2022, respectively)	141,933	43,589
Mortgage notes payable, net (amounts related to VIEs of $3,273,553 and $3,272,368 at March 31, 2023 and December 31, 2022, respectively)	3,273,553	3,272,368
Lease liabilities - finance leases (amounts related to VIEs of $20,641 and $20,604 at March 31, 2023 and December 31, 2022, respectively)	250,567	249,335
Accounts payable and accrued expenses (amounts related to VIEs of $37,595 and $29,466 at March 31, 2023 and December 31, 2022, respectively)	397,798	417,545
Other liabilities (amounts related to VIEs of $114,694 and $114,232 at March 31, 2023 and December 31, 2022, respectively)	$ 465,276	$ 450,918
Reedemable deferred stock units, units	103,454	97,853
Limited Partners' Capital Account, Units Outstanding (in units)	155,074,901	155,008,185
General Partners' Capital Account, Units Outstanding (in units)	1,754,892	1,749,682
NonControlling Interest Redeemable Partnership Units Common Units Shares Outstanding	16,527,638	16,531,172
NonControlling Interest Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Shares Outstanding	2,131,785	1,679,175
Variable Interest Entity, Primary Beneficiary [Member]
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,832,119 and $6,789,029 at March 31, 2023 and December 31, 2022, respectively)	$ 6,832,119	$ 6,789,029
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at March 31, 2023 and December 31, 2022, respectively)	21,000	21,000
Less: accumulated depreciation (amounts related to VIEs of $(1,405,167) and $(1,381,401) at March 31, 2023 and December 31, 2022, respectively)	(1,405,167)	(1,381,401)
Cash and cash equivalents (amounts related to VIEs of $233,981 and $259,658 at March 31, 2023 and December 31, 2022, respectively)	233,981	259,658
Tenant and other receivables, net (amounts related to VIEs of $13,108 and $16,521 at March 31, 2023 and December 31, 2022, respectively)	13,108	16,521
Accrued rental income, net (amounts related to VIEs of $375,008 and $367,138 at March 31, 2023 and December 31, 2022, respectively)	375,008	367,138
Deferred charges, net (amounts related to VIEs of $172,077 and $176,597 at March 31, 2023 and December 31, 2022, respectively)	172,077	176,597
Prepaid expenses and other assets (amounts related to VIEs of $40,737 and $11,647 at March 31, 2023 and December 31, 2022, respectively)	40,737	11,647
Mortgage notes payable, net (amounts related to VIEs of $3,273,553 and $3,272,368 at March 31, 2023 and December 31, 2022, respectively)	3,273,553	3,272,368
Lease liabilities - finance leases (amounts related to VIEs of $20,641 and $20,604 at March 31, 2023 and December 31, 2022, respectively)	20,641	20,604
Accounts payable and accrued expenses (amounts related to VIEs of $37,595 and $29,466 at March 31, 2023 and December 31, 2022, respectively)	37,595	29,466
Other liabilities (amounts related to VIEs of $114,694 and $114,232 at March 31, 2023 and December 31, 2022, respectively)	114,694	114,232
Variable Interest Entity, Primary Beneficiary [Member] | Boston Properties Limited Partnership
Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $6,832,119 and $6,789,029 at March 31, 2023 and December 31, 2022, respectively)	6,832,119	6,789,029
Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at March 31, 2023 and December 31, 2022, respectively)	21,000	21,000
Less: accumulated depreciation (amounts related to VIEs of $(1,405,167) and $(1,381,401) at March 31, 2023 and December 31, 2022, respectively)	(1,405,167)	(1,381,401)
Cash and cash equivalents (amounts related to VIEs of $233,981 and $259,658 at March 31, 2023 and December 31, 2022, respectively)	233,981	259,658
Tenant and other receivables, net (amounts related to VIEs of $13,108 and $16,521 at March 31, 2023 and December 31, 2022, respectively)	13,108	16,521
Accrued rental income, net (amounts related to VIEs of $375,008 and $367,138 at March 31, 2023 and December 31, 2022, respectively)	375,008	367,138
Deferred charges, net (amounts related to VIEs of $172,077 and $176,597 at March 31, 2023 and December 31, 2022, respectively)	172,077	176,597
Prepaid expenses and other assets (amounts related to VIEs of $40,737 and $11,647 at March 31, 2023 and December 31, 2022, respectively)	40,737	11,647
Mortgage notes payable, net (amounts related to VIEs of $3,273,553 and $3,272,368 at March 31, 2023 and December 31, 2022, respectively)	3,273,553	3,272,368
Lease liabilities - finance leases (amounts related to VIEs of $20,641 and $20,604 at March 31, 2023 and December 31, 2022, respectively)	20,641	20,604
Accounts payable and accrued expenses (amounts related to VIEs of $37,595 and $29,466 at March 31, 2023 and December 31, 2022, respectively)	37,595	29,466
Other liabilities (amounts related to VIEs of $114,694 and $114,232 at March 31, 2023 and December 31, 2022, respectively)	$ 114,694	$ 114,232

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Revenue
Lease		$ 756,875	$ 718,120
Total revenue		803,200	754,307
Expenses
Rental		291,308	270,255
General and administrative		55,802	43,194
Transaction costs		911	0
Depreciation and amortization		208,734	177,624
Total expenses		568,661	499,978
Other income (expense)
Loss from Unconsolidated Joint Ventures		(7,569)	2,189
Gains on sales of real estate		0	22,701
Interest and other income (loss)		10,941	1,228
Gains (losses) from investments in securities		1,665	(2,262)
Unrealized gain on non-real estate investment		259	0
Interest expense		(134,207)	(101,228)
Net income		105,628	176,957
Net income attributable to noncontrolling interests
Noncontrolling interests in property partnerships		(18,660)	(17,549)
Noncontrolling interest - common units of the Operating Partnership		(9,078)	(16,361)
Net income attributable to the Company		77,890	143,047
Net income attributable to the Company's common shareholders / unitholders		$ 77,890	$ 143,047
Basic earnings per common share / unit attributable to the Company
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)		$ 0.50	$ 0.91
Weighted average number of common shares / units outstanding (in shares / units)		156,803	156,650
Diluted earnings per common share / unit attributable to the Company
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)		$ 0.50	$ 0.91
Weighted average number of common and common equivalent shares / units outstanding (in shares / units)		157,043	157,004
Boston Properties Limited Partnership
Revenue
Lease		$ 756,875	$ 718,120
Total revenue		803,200	754,307
Expenses
Rental		291,308	270,255
General and administrative		55,802	43,194
Transaction costs		911	0
Depreciation and amortization		206,872	175,886
Total expenses		566,799	498,240
Other income (expense)
Loss from Unconsolidated Joint Ventures		(7,569)	2,189
Gains on sales of real estate		0	23,384
Interest and other income (loss)		10,941	1,228
Gains (losses) from investments in securities		1,665	(2,262)
Unrealized gain on non-real estate investment		259	0
Interest expense		(134,207)	(101,228)
Net income		107,490	179,378
Net income attributable to noncontrolling interests
Noncontrolling interests in property partnerships		(18,660)	(17,549)
Net income attributable to the Company		88,830	161,829
Net income attributable to the Company's common shareholders / unitholders		$ 88,830	$ 161,829
Basic earnings per common share / unit attributable to the Company
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)		$ 0.51	$ 0.93
Weighted average number of common shares / units outstanding (in shares / units)		174,652	174,276
Diluted earnings per common share / unit attributable to the Company
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)		$ 0.51	$ 0.93
Weighted average number of common and common equivalent shares / units outstanding (in shares / units)		174,892	174,630
Parking and Other [Member]
Revenue
Other revenue		$ 24,009	$ 21,734
Parking and Other [Member] | Boston Properties Limited Partnership
Revenue
Other revenue		24,009	21,734
Hotel [Member]
Revenue
Other revenue	[1]	8,101	4,557
Expenses
Operating expense		6,671	4,840
Hotel [Member] | Boston Properties Limited Partnership
Revenue
Other revenue		8,101	4,557
Expenses
Operating expense		6,671	4,840
Real Estate, Other [Member]
Revenue
Other revenue		5,235	4,065
Expenses
Operating expense		5,235	4,065
Real Estate, Other [Member] | Boston Properties Limited Partnership
Revenue
Other revenue		5,235	4,065
Expenses
Operating expense		5,235	4,065
Management Service [Member]
Revenue
Other revenue		8,980	5,831
Management Service [Member] | Boston Properties Limited Partnership
Revenue
Other revenue		$ 8,980	$ 5,831
[1]Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Net income		$ 105,628	$ 176,957
Other comprehensive income :
Effective portion of interest rate contracts		(6,538)	7,565
Amortization of interest rate contracts	[1]	1,675	1,676
Other comprehensive income (loss)		(4,863)	9,241
Comprehensive Income		100,765	186,198
Net income attributable to noncontrolling interests		(27,738)	(33,910)
Other comprehensive (income) loss attributable to noncontrolling interests		368	(1,064)
Comprehensive income attributable to the Company		73,395	151,224
Boston Properties Limited Partnership
Net income		107,490	179,378
Other comprehensive income :
Effective portion of interest rate contracts		(6,538)	7,565
Amortization of interest rate contracts	[2]	1,675	1,676
Other comprehensive income (loss)		(4,863)	9,241
Comprehensive Income		102,627	188,619
Net income attributable to noncontrolling interests		(18,804)	(17,693)
Comprehensive income attributable to the Company		$ 83,823	$ 170,926
[1]Amounts reclassified from comprehensive income primarily to interest expense within Boston Properties, Inc.’s Consolidated Statements of Operations[2]Amounts reclassified from comprehensive income primarily to interest expense within Boston Properties Limited Partnership’s Consolidated Statements of Operations.

Consolidated Statements Of Equi

Consolidated Statements Of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Dividends In Excess Of Earnings [Member]	Treasury Stock, at cost [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]	Noncontrolling interest - property partnerships [Member]
Equity, shares at Dec. 31, 2021		156,545,000
Equity, value at Dec. 31, 2021	$ 8,033,228	$ 1,565	$ 6,497,730	$ (625,891)	$ (2,722)	$ (36,662)	$ 642,655	$ 1,556,553
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares		141,000
Redemption of operating partnership units to common stock, value	0	$ 2	5,026				(5,028)
Allocated net income for the period	176,957			143,047			16,361	17,549
Dividends declared	(171,497)			(153,577)			(17,920)
Shares issued pursuant to stock purchase plan, shares		5,000
Shares issued pursuant to stock purchase plan, value	600		600
Net activity from stock option and incentive plan, shares		21,000
Net activity from stock option and incentive plan, value	18,921		(133)				19,054
Contributions from noncontrolling interests in property partnerships	849							849
Distributions to noncontrolling interests in property partnerships	(26,640)							(26,640)
Effective portion of interest rate contracts	7,565					6,800	765
Amortization of interest rate contracts	1,676					1,377	155	144
Reallocation of noncontrolling interest	0		6,440				(6,440)
Equity, shares at Mar. 31, 2022		156,712,000
Equity, value at Mar. 31, 2022	$ 8,041,659	$ 1,567	6,509,663	(636,421)	(2,722)	(28,485)	649,602	1,548,455
Equity, shares at Dec. 31, 2022	156,757,867	156,758,000
Equity, value at Dec. 31, 2022	$ 8,363,819	$ 1,568	6,539,147	(391,356)	(2,722)	(13,718)	683,583	1,547,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares		5,000
Redemption of operating partnership units to common stock, value	0	$ 0	195				(195)
Allocated net income for the period	105,628			77,890			9,078	18,660
Dividends declared	(172,054)			(153,693)			(18,361)
Shares issued pursuant to stock purchase plan, shares		9,000
Shares issued pursuant to stock purchase plan, value	586		586
Net activity from stock option and incentive plan, shares		58,000
Net activity from stock option and incentive plan, value	27,419		3,448				23,971
Contributions from noncontrolling interests in property partnerships	7,555							7,555
Distributions to noncontrolling interests in property partnerships	(21,606)							(21,606)
Effective portion of interest rate contracts	(6,538)					(5,870)	(668)
Amortization of interest rate contracts	1,675					1,374	157	144
Reallocation of noncontrolling interest	$ 0		5,938				(5,938)
Equity, shares at Mar. 31, 2023	156,829,793	156,830,000
Equity, value at Mar. 31, 2023	$ 8,306,484	$ 1,568	$ 6,549,314	$ (467,159)	$ (2,722)	$ (18,214)	$ 691,627	$ 1,552,070

Consolidated Statement of Capit

Consolidated Statement of Capital and Noncontrolling Interests - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Common Stock, Shares, Outstanding	156,829,793		156,757,867
Net activity from stock option and incentive plan, value	$ 27,419	$ 18,921
Effective portion of interest rate contracts	(6,538)	7,565
Amortization of interest rate contracts	1,675	1,676
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	$ (21,606)	$ (26,640)
General Partner [Member]
Common Stock, Shares, Outstanding	1,755,000	1,749,000	1,750,000	1,746,000
Net activity from contributions and unearned compensation	5,000
Conversion of redeemable partnership units		3,000
Limited Partner [Member]
Common Stock, Shares, Outstanding	155,075,000	154,962,000	155,008,000	154,799,000
Net activity from contributions and unearned compensation	62,000	25,000
Conversion of redeemable partnership units	5,000	138,000
Partners' Capital (General and Limited Partners)[Member]
Beginning Balance	$ 5,449,936	$ 3,914,832	$ 5,299,428	$ 4,173,290
Net activity from contributions and unearned compensation, value	4,032	467
Allocated net income for the period	79,752	145,468
Distributions	(153,693)	(153,577)
Conversion of redeemable partnership units, value	195	5,028
Adjustment to reflect redeemable partnership units at redemption value	220,222	(255,844)
Accumulated Other Comprehensive Loss [Member]
Beginning Balance	(18,214)	(28,485)	(13,718)	(36,662)
Effective portion of interest rate contracts	(5,870)	6,800
Amortization of interest rate contracts	1,374	1,377
Noncontrolling interest - property partnerships [Member]
Beginning Balance	1,552,070	1,548,455	1,547,317	1,556,553
Allocated net income for the period	18,660	17,549
Amortization of interest rate contracts	144	144
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	(21,606)	(26,640)
Total Capital [Member]
Beginning Balance	6,983,792	5,434,802	6,833,027	5,693,181
Net activity from contributions and unearned compensation, value	4,032	467
Allocated net income for the period	98,412	163,017
Distributions	(153,693)	(153,577)
Conversion of redeemable partnership units, value	195	5,028
Adjustment to reflect redeemable partnership units at redemption value	220,222	(255,844)
Effective portion of interest rate contracts	(5,870)	6,800
Amortization of interest rate contracts	1,518	1,521
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	(21,606)	(26,640)
Noncontrolling interest - Redeemable partnership units [Member]
Beginning Balance	1,074,648	2,347,834	$ 1,280,886	$ 2,078,603
Net activity from contributions and unearned compensation, value	23,973	19,054
Allocated net income for the period	9,078	16,361
Distributions	(18,361)	(17,920)
Conversion of redeemable partnership units, value	(195)	(5,028)
Adjustment to reflect redeemable partnership units at redemption value	(220,222)	255,844
Effective portion of interest rate contracts	(668)	765
Amortization of interest rate contracts	$ 157	$ 155

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net income	$ 105,628	$ 176,957
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	208,734	177,624
Amortization of right of use assets - operating leases	652	529
Non-cash compensation expense	26,262	21,235
Loss (income) from unconsolidated joint ventures	7,569	(2,189)
Distributions of net cash flow from operations of unconsolidated joint ventures	5,996	6,385
Losses (gains) from investments in securities	(1,665)	2,262
Allowance for current expected credit losses	45	(234)
Non-cash portion of interest expense	7,387	5,960
Gains on sales of real estate	0	(22,701)
Unrealized gain on non-real estate investment	(259)	0
Change in assets and liabilities:
Tenant and other receivables, net	7,518	17,635
Notes receivable, net	0	(8)
Accrued rental income, net	(18,619)	(29,567)
Prepaid expenses and other assets	(97,762)	(71,731)
Lease liabilities - operating leases	(251)	116
Accounts payable and accrued expenses	(8,505)	(31,800)
Accrued interest payable	10,626	(3,933)
Other liabilities	16,565	(12,146)
Tenant leasing costs	(35,911)	(14,904)
Total adjustments	128,382	42,533
Net cash provided by operating activities	234,010	219,490
Cash flows from investing activities:
Acquisitions of real estate	0	(3,580)
Construction in progress	(119,682)	(100,313)
Building and other capital improvements	(39,100)	(26,811)
Tenant improvements	(67,175)	(55,168)
Proceeds from sales of real estate	0	35,397
Capital contributions to unconsolidated joint ventures	(60,745)	(26,293)
Capital distributions from unconsolidated joint ventures	0	20,095
Investment in non-real estate investments	(733)	0
Investments in securities, net	1,843	5,338
Net cash used in investing activities	(285,592)	(151,335)
Cash flows from financing activities:
Borrowings on unsecured line of credit	0	190,000
Repayments of unsecured line of credit	0	(80,000)
Borrowings on unsecured term loan	1,200,000	0
Repayment of unsecured term loan	(730,000)	0
Deferred financing costs	(6,213)	(359)
Net activity from equity transactions	586	(332)
Dividends and distributions	(171,270)	(170,488)
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	(21,606)	(26,640)
Net cash provided by (used in) financing activities	279,052	(86,970)
Net increase (decrease) in cash and cash equivalents and cash held in escrows	227,470	(18,815)
Cash and cash equivalents and cash held in escrows, beginning of period	736,812	501,158
Cash and cash equivalents and cash held in escrows, end of period	964,282	482,343
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	690,333	452,692
Cash held in escrows, beginning of period	46,479	48,466
Cash and cash equivalents, end of period	918,952	436,271
Cash held in escrows,end of period	45,330	46,072
Supplemental disclosures:
Cash paid for interest	125,698	111,904
Interest capitalized	10,589	13,740
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(56,391)	(34,946)
Change in real estate included in accounts payable and accrued expenses	11,692	16,907
Dividends and distributions declared but not paid	171,427	170,869
Conversions of noncontrolling interests to stockholders’ equity	195	5,028
Issuance of restricted securities to employees and non-employee directors	46,516	46,082
Boston Properties Limited Partnership
Net income	107,490	179,378
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	206,872	175,886
Amortization of right of use assets - operating leases	652	529
Non-cash compensation expense	26,262	21,235
Loss (income) from unconsolidated joint ventures	7,569	(2,189)
Distributions of net cash flow from operations of unconsolidated joint ventures	5,996	6,385
Losses (gains) from investments in securities	(1,665)	2,262
Allowance for current expected credit losses	45	(234)
Non-cash portion of interest expense	7,387	5,960
Gains on sales of real estate	0	(23,384)
Unrealized gain on non-real estate investment	(259)	0
Change in assets and liabilities:
Tenant and other receivables, net	7,518	17,635
Notes receivable, net	0	(8)
Accrued rental income, net	(18,619)	(29,567)
Prepaid expenses and other assets	(97,762)	(71,731)
Lease liabilities - operating leases	(251)	116
Accounts payable and accrued expenses	(8,505)	(31,800)
Accrued interest payable	10,626	(3,933)
Other liabilities	16,565	(12,146)
Tenant leasing costs	(35,911)	(14,904)
Total adjustments	126,520	40,112
Net cash provided by operating activities	234,010	219,490
Cash flows from investing activities:
Acquisitions of real estate	0	(3,580)
Construction in progress	(119,682)	(100,313)
Building and other capital improvements	(39,100)	(26,811)
Tenant improvements	(67,175)	(55,168)
Proceeds from sales of real estate	0	35,397
Capital contributions to unconsolidated joint ventures	(60,745)	(26,293)
Capital distributions from unconsolidated joint ventures	0	20,095
Investment in non-real estate investments	(733)	0
Investments in securities, net	1,843	5,338
Net cash used in investing activities	(285,592)	(151,335)
Cash flows from financing activities:
Borrowings on unsecured line of credit	0	190,000
Repayments of unsecured line of credit	0	(80,000)
Borrowings on unsecured term loan	1,200,000	0
Repayment of unsecured term loan	(730,000)	0
Deferred financing costs	(6,213)	(359)
Net activity from equity transactions	586	(332)
Dividends and distributions	(171,270)	(170,488)
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	(21,606)	(26,640)
Net cash provided by (used in) financing activities	279,052	(86,970)
Net increase (decrease) in cash and cash equivalents and cash held in escrows	227,470	(18,815)
Cash and cash equivalents and cash held in escrows, beginning of period	736,812	501,158
Cash and cash equivalents and cash held in escrows, end of period	964,282	482,343
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	690,333	452,692
Cash held in escrows, beginning of period	46,479	48,466
Cash and cash equivalents, end of period	918,952	436,271
Cash held in escrows,end of period	45,330	46,072
Supplemental disclosures:
Cash paid for interest	125,698	111,904
Interest capitalized	10,589	13,740
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(55,142)	(34,946)
Change in real estate included in accounts payable and accrued expenses	11,692	16,907
Dividends and distributions declared but not paid	171,427	170,869
Conversions of noncontrolling interests to stockholders’ equity	195	5,028
Issuance of restricted securities to employees and non-employee directors	$ 46,516	$ 46,082

Organization

Organization	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization BXP is a fully integrated, self-administered and self-managed REIT. BXP is the sole general partner of BPLP, its operating partnership, and at March 31, 2023 owned an approximate 89.4% (89.6% at December 31, 2022) general and limited partnership interest in BPLP. Unless stated otherwise or the context requires, the “Company” refers to BXP and its subsidiaries, including BPLP and its consolidated subsidiaries. Partnership interests in BPLP include: • common units of partnership interest (also referred to as “OP Units”) and • long term incentive units of partnership interest (also referred to as “LTIP Units”) Unless specifically noted otherwise, all references to OP Units exclude units held by BXP. A holder of an OP Unit may present the OP Unit to BPLP for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, BPLP is obligated to redeem the OP Unit for cash equal to the value of a share of common stock of BXP (“Common Stock”). In lieu of such cash redemption, BXP may elect to acquire the OP Unit for one share of Common Stock. Because the number of shares of Common Stock outstanding at all times equals the number of OP Units that BXP owns, one share of Common Stock is generally the economic equivalent of one OP Unit, and the quarterly distribution that may be paid to the holder of an OP Unit equals the quarterly dividend that may be paid to the holder of a share of Common Stock. The Company uses LTIP Units as a form of time-based, restricted equity compensation and as a form of performance-based equity compensation for employees, and has previously granted LTIP Units in the form of (1) 2012 outperformance plan awards (“2012 OPP Units”) and (2) 2013 - 2023 multi-year, long-term incentive program awards (also referred to as “MYLTIP Units”), each of which, upon the satisfaction of certain performance-based and time-based vesting conditions, is convertible into one OP Unit. The three Properties At March 31, 2023, the Company owned or had joint venture interests in a portfolio of 192 commercial real estate properties (the “Properties”) aggregating approximately 54.5 million net rentable square feet of primarily premier workplaces, including 15 properties under construction/redevelopment totaling approximately 4.0 million net rentable square feet. At March 31, 2023, the Properties consisted of: • 171 office and life sciences properties (including 12 properties under construction/redevelopment); • 14 retail properties (including two properties under construction/redevelopment); • six residential properties (including one property under construction ) ; and • one hotel. The Company considers premier workplaces to be well-located buildings that are modern structures or have been modernized to compete with newer buildings and professionally managed and maintained. As such, these properties attract high-quality tenants and command upper-tier rental rates.

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	2. Summary of Significant Accounting Policies BXP does not have any other significant assets, liabilities or operations, other than its investment in BPLP, nor does it have employees of its own. BPLP, not BXP, generally executes all significant business relationships other than transactions involving securities of BXP. All majority-owned subsidiaries and joint ventures over which the Company has financial and operating control and variable interest entities (“VIEs”) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income. The accompanying interim financial statements are unaudited; however, the financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information and in conjunction with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting solely of normal recurring matters) necessary for a fair statement of the financial statements for these interim periods have been included. The results of operations for the interim periods are not necessarily indicative of the results to be obtained for other interim periods or for the full fiscal year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosure required by GAAP. These financial statements should be read in conjunction with the Company’s financial statements and notes thereto contained in the Company’s Annual Report in the Company’s Form 10-K for its fiscal year ended December 31, 2022. The Company bases its estimates on historical experience and on various other assumptions that it considers to be reasonable under the circumstances, including the impact of extraordinary events such as the coronavirus (“COVID-19”) pandemic, the results of which form the basis for making significant judgments about the carrying values of assets and liabilities, assessments of future collectability, and other areas of the financial statements that are impacted by the use of estimates. Actual results may differ from these estimates under different assumptions or conditions. Variable Interest Entities (VIEs) Consolidated VIEs are those for which the Company is considered to be the primary beneficiary of a VIE. The primary beneficiary is the entity that has a controlling financial interest in the VIE, which is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and (2) the obligation to absorb losses or the right to receive the returns from the VIE that could potentially be significant to the VIE. The assets of each VIE are only available to satisfy such VIE's respective liabilities. The Company has determined that it is the primary beneficiary for six of the seven entities that are VIEs as of March 31, 2023. Consolidated Variable Interest Entities As of March 31, 2023, BXP has identified six consolidated VIEs, including BPLP. Excluding BPLP, the VIEs consisted of the following five in-service properties: 767 Fifth Avenue (the General Motors Building), Times Square Tower, 601 Lexington Avenue, Atlantic Wharf Office Building and 100 Federal Street. The Company consolidates these VIEs because it is the primary beneficiary. The third parties’ interests in these consolidated entities (excluding BPLP’s interest) are reflected as noncontrolling interests in property partnerships in the accompanying consolidated financial statements (See Note 8). In addition, BXP’s only significant asset is its investment in BPLP and, consequently, substantially all of BXP’s assets and liabilities are the assets and liabilities of BPLP. Variable Interest Entities Not Consolidated As of March 31, 2023, the Company has determined that the Platform 16 Holdings LP joint venture is a VIE. The Company does not consolidate this entity as the Company does not have the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and, therefore, the Company is not considered to be the primary beneficiary. Fair Value of Financial Instruments The Company follows the authoritative guidance for fair value measurements when valuing its financial instruments for disclosure purposes. The table below presents for March 31, 2023 and December 31, 2022, the financial instruments that are being valued for disclosure purposes as well as the Level at which they are categorized (as defined in Accounting Standards Codification (“ASC”) 820 “Fair Value Measurements and Disclosures”). Financial Instrument Level Unsecured senior notes (1) Level 1 Related party note receivable Level 3 Sales-type lease receivable Level 3 Mortgage notes payable Level 3 Unsecured line of credit Level 3 Unsecured term loan Level 3 _______________ (1) If trading volume for the period is low, the valuation could be categorized as Level 2. Because the Company’s valuations of its financial instruments are based on the above Levels and involve the use of estimates, the actual fair values of its financial instruments may differ materially from those estimates. In addition, the Company’s estimated fair values for these instruments as of the end of the applicable reporting period are not projections of, nor necessarily indicative of, estimated or actual fair values in future reporting periods. The following table presents the aggregate carrying value of the Company’s related party note receivable, net, sales-type lease receivable, net, mortgage notes payable, net, unsecured senior notes, net, unsecured line of credit and unsecured term loan, net and the Company’s corresponding estimate of fair value as of March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 December 31, 2022 Carrying Estimated Carrying Estimated Related party note receivable, net $ 78,544 $ 79,472 $ 78,576 $ 79,220 Sales-type lease receivable, net 13,028 13,086 12,811 13,045 Total $ 91,572 $ 92,558 $ 91,387 $ 92,265 Mortgage notes payable, net $ 3,273,553 $ 2,826,826 $ 3,272,368 $ 2,744,479 Unsecured senior notes, net 10,240,967 8,759,487 10,237,968 9,135,512 Unsecured line of credit — — — — Unsecured term loan, net 1,194,916 1,200,000 730,000 730,000 Total $ 14,709,436 $ 12,786,313 $ 14,240,336 $ 12,609,991

Real Estate

Real Estate	3 Months Ended
	Mar. 31, 2023
Real Estate [Abstract]
Real Estate	3. Real Estate BXP Real estate consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 December 31, 2022 Land $ 5,189,287 $ 5,189,811 Right of use assets - finance leases 237,503 237,510 Right of use assets - operating leases 166,699 167,351 Land held for future development (1) 626,137 721,501 Buildings and improvements 15,783,962 15,820,724 Tenant improvements 3,291,322 3,200,743 Furniture, fixtures and equipment 50,242 50,310 Construction in progress 618,770 406,574 Total 25,963,922 25,794,524 Less: Accumulated depreciation (6,424,547) (6,298,082) $ 19,539,375 $ 19,496,442 _______________ (1) Includes pre-development costs. BPLP Real estate consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 December 31, 2022 Land $ 5,094,578 $ 5,095,102 Right of use assets - finance leases 237,503 237,510 Right of use assets - operating leases 166,699 167,351 Land held for future development (1) 626,137 721,501 Buildings and improvements 15,512,406 15,547,919 Tenant improvements 3,291,322 3,200,743 Furniture, fixtures and equipment 50,242 50,310 Construction in progress 618,770 406,574 Total 25,597,657 25,427,010 Less: Accumulated depreciation (6,306,326) (6,180,474) $ 19,291,331 $ 19,246,536 _______________ (1) Includes pre-development costs. Developments/Redevelopments On January 5, 2023, the Company commenced the development of 290 Binney Street, an approximately 566,000 net rentable square foot laboratory/life sciences project in Cambridge, Massachusetts. Concurrent with the commencement of this project, the Kendall Center Blue Parking Garage was taken out of service and demolished to support the development of this project. 290 Binney Street is 100% pre-leased to AstraZeneca.

Leases

Leases	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Lessor, Operating Leases [Text Block]	4. Leases The Company estimates the collectability of its accrued rent and accounts receivable balances related to lease revenue. When evaluating the collectability of these accrued rent and accounts receivable balances, management considers tenant creditworthiness, current economic trends, including the impact of the COVID-19 pandemic on tenants’ businesses, and changes in tenants’ payment patterns, on a lease-by-lease basis. If the Company determines that the accrued rent and/or accounts receivable balances are no longer probable of collection then the balances are written-off and the lease is recognized on a cash basis. If applicable, information related to write-offs of accrued rent, net balances and accounts receivable, net balances and reinstatements of accrued rent balances for the Company’s unconsolidated joint ventures can be found in Note 5. Lessor The following table summarizes the components of lease revenue recognized for its operating and sales-type leases during the three months ended March 31, 2023 and 2022 included within the Company's Consolidated Statements of Operations (in thousands): Three months ended March 31, Lease Revenue 2023 2022 Fixed contractual payments $ 621,646 $ 599,607 Variable lease payments 135,003 118,513 Sales-type lease income 226 — $ 756,875 $ 718,120

Investments in Unconsolidated J

Investments in Unconsolidated Joint Ventures	3 Months Ended
	Mar. 31, 2023
Investments In Unconsolidated Joint Ventures [Abstract]
Investments In Unconsolidated Joint Ventures	5. Investments in Unconsolidated Joint Ventures The investments in unconsolidated joint ventures consist of the following at March 31, 2023 and December 31, 2022: Carrying Value of Investment (1) Entity Properties Nominal % Ownership March 31, 2023 December 31, 2022 (in thousands) Square 407 Limited Partnership Market Square North 50.00 % $ (6,097) $ (6,198) BP/CRF Metropolitan Square LLC Metropolitan Square 20.00 % (38,782) (37,629) 901 New York, LLC 901 New York Avenue 25.00 % (2) (12,311) (12,493) WP Project Developer LLC Wisconsin Place Land and Infrastructure 33.33 % (3) 31,723 31,971 500 North Capitol Venture LLC 500 North Capitol Street, NW 30.00 % (8,941) (9,185) 501 K Street LLC 1001 6th Street 50.00 % (4) 43,661 42,922 Podium Developer LLC The Hub on Causeway - Podium 50.00 % 45,622 46,839 Residential Tower Developer LLC Hub50House 50.00 % 42,046 45,414 Hotel Tower Developer LLC The Hub on Causeway - Hotel Air Rights 50.00 % 12,582 12,366 Office Tower Developer LLC 100 Causeway Street 50.00 % 59,811 59,716 1265 Main Office JV LLC 1265 Main Street 50.00 % 3,605 3,465 BNY Tower Holdings LLC Dock 72 50.00 % (5) (15,362) (19,921) CA-Colorado Center, LLC Colorado Center 50.00 % 234,635 233,862 7750 Wisconsin Avenue LLC 7750 Wisconsin Avenue 50.00 % 51,549 52,152 BP-M 3HB Venture LLC 3 Hudson Boulevard 25.00 % 115,966 116,397 SMBP Venture LP Santa Monica Business Park 55.00 % 161,786 164,735 Platform 16 Holdings LP Platform 16 55.00 % (6) 171,010 158,109 Gateway Portfolio Holdings LLC Gateway Commons 50.00 % 337,535 324,038 Rosecrans-Sepulveda Partners 4, LLC Beach Cities Media Campus 50.00 % 26,987 27,000 Safeco Plaza REIT LLC Safeco Plaza 33.67 % (7) 68,196 69,785 360 PAS Holdco LLC 360 Park Avenue South 42.21 % (8) 116,828 114,992 PR II/BXP Reston Gateway LLC Reston Next Residential 20.00 % (9) 11,431 11,351 751 Gateway Holdings LLC 751 Gateway 49.00 % 85,430 80,714 200 Fifth Avenue JV LLC 200 Fifth Avenue 26.69 % 114,919 120,083 ABXP Worldgate Investments LLC 13100 and 13150 Worldgate Drive 50.00 % 17,295 N/A $ 1,671,124 $ 1,630,485 _______________ (1) Investments with deficit balances aggregating approximately $81.5 million and $85.4 million at March 31, 2023 and December 31, 2022, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets. (2) The Company’s economic ownership has increased based on the achievement of certain return thresholds. At March 31, 2023 and December 31, 2022, the Company’s economic ownership was approximately 50%. (3) The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project. (4) Under the joint venture agreement for this land parcel, the partner will be entitled to up to two additional payments from the venture based on increases in total entitled square footage of the project in excess of 520,000 square feet and achieving certain project returns at stabilization. (5) This property includes net equity balances from the amenity joint venture. (6) This entity is a VIE (See Note 2). (7) The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. (8) The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 5.837% indirect ownership in the joint venture, and (3) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. The Company’s partners will fund required capital until their aggregate investment is approximately 58% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests. (9) The Company’s partner will fund required capital until its aggregate investment is approximately 80% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests. Certain of the Company’s unconsolidated joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures. Under certain of the Company’s joint venture agreements, if certain return thresholds are achieved, the partners or the Company will be entitled to an additional promoted interest or payments. The combined summarized balance sheets of the Company’s unconsolidated joint ventures are as follows: March 31, 2023 December 31, 2022 (in thousands) ASSETS Real estate and development in process, net (1) $ 6,649,580 $ 6,537,554 Other assets 755,055 756,786 Total assets $ 7,404,635 $ 7,294,340 LIABILITIES AND MEMBERS’/PARTNERS’ EQUITY Mortgage and notes payable, net $ 4,037,789 $ 4,022,746 Other liabilities (2) 723,660 716,271 Members’/Partners’ equity 2,643,186 2,555,323 Total liabilities and members’/partners’ equity $ 7,404,635 $ 7,294,340 Company’s share of equity $ 1,271,419 $ 1,238,929 Basis differentials (3) 399,705 391,556 Carrying value of the Company’s investments in unconsolidated joint ventures (4) $ 1,671,124 $ 1,630,485 _______________ (1) At March 31, 2023 and December 31, 2022, this amount included right of use assets - finance leases totaling approximately $248.9 million. At March 31, 2023 and December 31, 2022, this amount included right of use assets - operating leases totaling approximately $20.9 million and $21.2 million, respectively. (2) At March 31, 2023 and December 31, 2022, this amount included lease liabilities - finance leases totaling approximately $381.0 million and $382.2 million, respectively. At March 31, 2023 and December 31, 2022, this amount included lease liabilities - operating leases totaling approximately $30.5 million. (3) This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows: March 31, 2023 December 31, 2022 Property (in thousands) Colorado Center $ 301,097 $ 301,820 200 Fifth Avenue 99,381 94,497 Gateway Commons 47,707 47,808 Dock 72 (98,120) (98,980) These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities. (4) Investments with deficit balances aggregating approximately $81.5 million and $85.4 million at March 31, 2023 and December 31, 2022, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets. The combined summarized statements of operations of the Company’s unconsolidated joint ventures are as follows: Three months ended March 31, 2023 2022 (in thousands) Total revenue (1) $ 151,423 $ 124,491 Expenses Operating 57,206 45,641 Transaction costs 74 — Depreciation and amortization 49,978 44,664 Total expenses 107,258 90,305 Other income (expense) Loss from early extinguishment of debt — (1,327) Interest expense (57,250) (30,373) Unrealized loss on derivative instruments (10,610) — Net income (loss) $ (23,695) $ 2,486 Company’s share of net income (loss) $ (6,902) $ 3,394 Basis differential (2) (667) (1,205) Income (loss) from unconsolidated joint ventures $ (7,569) $ 2,189 _______________ (1) Includes straight-line rent adjustments of approximately $6.3 million and $27.5 million for the three months ended March 31, 2023 and 2022, respectively. (2) Includes straight-line rent adjustments of approximately $0.3 million and $0.1 million for the three months ended March 31, 2023 and 2022, respectively. Also includes net above-/below-market rent adjustments of approximately $0.2 million and $0.1 million for the three months ended March 31, 2023 and 2022, respectively. On January 31, 2023, the Company acquired a 50% interest in a joint venture that owns 13100 and 13150 Worldgate Drive located in Herndon, Virginia for a gross purchase price of approximately $17.0 million. The acquisition was completed with available cash. 13100 and 13150 Worldgate Drive consists of two vacant office buildings aggregating approximately 350,000 rentable square feet and a 1,200-space structured parking deck situated on a 10-acre site. The joint venture intends to redevelop the property for residential use. There can be no assurance that the joint venture will commence the development as currently contemplated or at all.

Debt

Debt	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Unsecured Debt Disclosure	6. Debt Unsecured Term Loan On January 4, 2023, BPLP entered into a credit agreement that provided for a $1.2 billion unsecured term loan facility (the “2023 Unsecured Term Loan”). Under the credit agreement, BPLP may, at any time prior to the maturity date, increase total commitments by up to an additional $300.0 million in aggregate principal amount by increasing the existing 2023 Unsecured Term Loan or incurring one or more additional term loans, in each case, subject to syndication of the increase and other conditions. The 2023 Unsecured Term Loan matures on May 16, 2024, with one 12-month extension option, subject to customary conditions. Upon entry into the credit agreement, BPLP exercised its option to draw $1.2 billion under the 2023 Unsecured Term Loan, a portion of which was used to repay in full the $730.0 million outstanding under its prior unsecured credit agreement (the “2022 Unsecured Term Loan”), which was scheduled to mature on May 16, 2023. There was no prepayment penalty associated with the repayment of the 2022 Unsecured Term Loan. At BPLP’s option, loans under the 2023 Unsecured Term Loan will bear interest at a rate per annum equal to (1) a base rate equal to the greatest of (a) the Federal Funds rate plus 0.5%, (b) the administrative agent’s prime rate, (c) Term SOFR for a one-month period plus 1.00%, and (d) 1.00%, in each case, plus a margin ranging from 0 to 60 basis points based on BPLP’s credit rating; or (2) a rate equal to adjusted Term SOFR with a one-month period plus a margin ranging from 75 to 160 basis points based on BPLP’s credit rating. Based on BPLP’s credit rating upon entry into the credit agreement, the base rate margin is 0 basis points and the Term SOFR margin is 0.85%. As of March 31, 2023, the 2023 Unsecured Term Loan bears interest at a rate equal to adjusted Term SOFR plus 0.85% (See Note 13). At March 31, 2023, BPLP had $1.2 billion outstanding under the 2023 Unsecured Term Loan.

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	7. Commitments and Contingencies General In the normal course of business, the Company guarantees its performance of services or indemnifies third parties against its negligence. In addition, in the normal course of business, the Company guarantees to certain tenants the obligations of its subsidiaries for the payment of tenant improvement allowances and brokerage commissions in connection with their leases and limited costs arising from delays in delivery of their premises. The Company had letter of credit and performance obligations related to lender and development requirements that total approximately $25.7 million at March 31, 2023. Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures. From time to time, under certain of the Company’s joint venture agreements, if certain return thresholds are achieved, either the Company or its partners may be entitled to an additional promoted interest or payments. From time to time, the Company (or ventures in which the Company has an ownership interest) has agreed, and may in the future agree, to (1) guarantee portions of the principal, interest and other amounts in connection with their borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with their borrowings and (3) provide guarantees to lenders, tenants and other third parties for the completion of development projects. The Company has agreements with its outside or joint venture partners whereby the partners agree to reimburse the joint venture for their share of any payments made under the guarantee. In some cases, the Company earns a fee from the applicable joint venture for providing the guarantee. In connection with the refinancing of 767 Fifth Avenue’s (the General Motors Building) secured loan by the Company’s consolidated joint venture entity, 767 Venture, LLC, the Company guaranteed the consolidated entity’s obligation to fund various reserves for tenant improvement costs and allowances, leasing commissions and free rent obligations in lieu of cash deposits. As of March 31, 2023, the maximum funding obligation under the guarantee was approximately $12.5 million. The Company earns a fee from the joint venture for providing the guarantee and has an agreement with the outside partners to reimburse the joint venture for their share of any payments made under the guarantee. As of March 31, 2023, no amounts related to the guarantee were recorded as liabilities in the Company’s consolidated financial statements. In connection with the development of the Company’s 290 Binney Street project located in Cambridge, Massachusetts, which commenced on January 5, 2023 (see Note 3), the Cambridge Zoning Ordinance requires that a building permit for the construction of a residential project of at least 400,000 square feet be issued prior to or concurrently with the issuance of a building permit for the commercial building. 290 Binney Street and the residential project are components of the Company’s future life sciences development project located in the heart of Kendall Square in Cambridge, Massachusetts, proposed to ultimately consist of two premier workplace properties aggregating approximately 1.1 million rentable square feet of life sciences space and the approximately 400,000 square foot residential building. The commencement of construction of each phase of the overall project is subject to various conditions, some of which are not within the Company’s control. There can be no assurance that the conditions will be satisfied or that the Company will commence the development of the remaining phases on the terms and schedule currently contemplated or at all. Insurance The Company’s property insurance program per occurrence limits are $1.0 billion for its portfolio insurance program, including coverage for acts of terrorism other than nuclear, biological, chemical or radiological terrorism (“Terrorism Coverage”). The Company also carries $1.35 billion of property insurance in excess of the $1.0 billion of coverage in the Company’s property insurance program for 601 Lexington Avenue, New York, New York, consisting of $750 million of property and Terrorism Coverage in excess of the Company’s property insurance program and $600 million of Terrorism Coverage only in excess of the $1.75 billion of coverage. Certain properties, including the General Motors Building located at 767 Fifth Avenue in New York, New York (“767 Fifth Avenue”), are currently insured in separate insurance programs. The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including Terrorism Coverage. The Company also currently carries nuclear, biological, chemical and radiological terrorism insurance coverage for acts of terrorism certified under the Federal Terrorism Risk Insurance Act (as amended, “TRIA”) (“NBCR Coverage”), which is provided by IXP as a direct insurer, for the properties in the Company’s portfolio, including 767 Fifth Avenue, but excluding certain other properties owned in joint ventures with third parties or which the Company manages. The per occurrence limit for NBCR Coverage is $1.0 billion. Under TRIA, after the payment of the required deductible and coinsurance, the NBCR Coverage provided by IXP is backstopped by the Federal Government if the aggregate industry insured losses resulting from a certified act of terrorism exceed a “program trigger.” The program trigger is $200 million, the coinsurance is 20% and the deductible is 20% of the premiums earned by the insurer for the year prior to a claim. If the Federal Government pays out for a loss under TRIA, it is mandatory that the Federal Government recoup the full amount of the loss from insurers offering TRIA coverage after the payment of the loss pursuant to a formula in TRIA. The Company may elect to terminate the NBCR Coverage if the Federal Government seeks recoupment for losses paid under TRIA, if TRIA is not extended after its expiration on December 31, 2027, if there is a change in its portfolio or for any other reason. The Company intends to continue to monitor the scope, nature and cost of available terrorism insurance. The Company also currently carries earthquake insurance on its properties located in areas known to be subject to earthquakes. Specifically, the Company currently carries earthquake insurance which covers its San Francisco and Los Angeles regions with a $330 million per occurrence limit, and a $330 million annual aggregate limit, $30 million of which is provided by IXP, as a direct insurer. This insurance is subject to a deductible in the amount of 5% of the value of the affected property. In addition, the Company currently carries earthquake insurance which covers its Seattle region with a $110 million per occurrence limit, and a $110 million annual aggregate limit. This insurance is subject to a deductible in the amount of 2% of the value of the affected property. The amount of the Company’s earthquake insurance coverage may not be sufficient to cover losses from earthquakes. In addition, the amount of earthquake coverage could impact the Company’s ability to finance properties subject to earthquake risk. The Company may discontinue earthquake insurance or change the structure of its earthquake insurance program on some or all of its properties in the future if the premiums exceed the Company’s estimation of the value of the coverage. IXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s earthquake insurance coverage for its Greater San Francisco and Los Angeles properties and the Company’s NBCR Coverage. Insofar as the Company owns IXP, it is responsible for its liquidity and capital resources, and the accounts of IXP are part of the Company’s consolidated financial statements. In particular, if a loss occurs which is covered by the Company’s NBCR Coverage but is less than the applicable program trigger under TRIA, IXP would be responsible for the full amount of the loss without any backstop by the Federal Government. IXP would also be responsible for any recoupment charges by the Federal Government in the event losses are paid out and its insurance policy is maintained after the payout by the Federal Government. If the Company experiences a loss and IXP is required to pay under its insurance policy, the Company would ultimately record the loss to the extent of the required payment. Therefore, insurance coverage provided by IXP should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance. In addition, BPLP has issued a guarantee to cover liabilities of IXP in the amount of $20.0 million. The Company continues to monitor the state of the insurance market in general, and the scope and costs of coverage for acts of terrorism, earthquakes and pandemics, in particular, but the Company cannot anticipate what coverage will be available on commercially reasonable terms in future policy years. There are other types of losses, such as from wars, for which the Company cannot obtain insurance at all or at a reasonable cost. With respect to

Noncontrolling Interests

Noncontrolling Interests	3 Months Ended
	Mar. 31, 2023
Noncontrolling Interest [Abstract]
Noncontrolling Interest Disclosure [Text Block]	8. Noncontrolling Interests Noncontrolling interests relate to the interests in BPLP not owned by BXP and interests in consolidated property partnerships not wholly-owned by the Company. As of March 31, 2023, the noncontrolling interests in BPLP consisted of 16,527,638 OP Units, 2,131,785 LTIP Units (including 514,854 LTIP Units earned by employees under the Company’s multi-year long-term incentive awards granted between 2012 and 2020 (i.e., 2012 OPP and 2013 - 2020 MYLTIP awards)), 350,989 2021 MYLTIP Units, 253,453 2022 MYLTIP Units and 322,053 2023 MYLTIP Units held by parties other than BXP. Noncontrolling Interest—Common Units During the three months ended March 31, 2023, 5,188 OP Units were presented by the holders for redemption (including an aggregate of 5,188 OP Units issued upon conversion of LTIP Units, 2012 OPP Units and MYLTIP Units) and were redeemed by BXP in exchange for an equal number of shares of Common Stock. At March 31, 2023, BPLP had outstanding 350,989 2021 MYLTIP Units, 253,453 2022 MYLTIP Units and 322,053 2023 MYLTIP Units. Prior to the end of the respective three On February 3, 2023, the measurement period for the Company’s 2020 MYLTIP awards ended and, based on BXP’s relative TSR performance, the final payout was determined to be 50% of target, or an aggregate of approximately $3.8 million (after giving effect to employee separations). As a result, an aggregate of 152,460 2020 MYLTIP Units that had been previously granted were automatically forfeited. The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2019 MYLTIP Units and, after the February 3, 2023 measurement date, the 2020 MYLTIP Units) and its distributions on the 2020 MYLTIP Units (prior to the February 3, 2023 measurement date) and 2021 - 2023 MYLTIP Units (after the February 7, 2023 issuance date of the 2023 MYLTIP Units) that occurred during the three months ended March 31, 2023: Record Date Payment Date Distributions per OP Unit and LTIP Unit Distributions per MYLTIP Unit March 31, 2023 April 28, 2023 $0.98 $0.098 December 30, 2022 January 30, 2023 $0.98 $0.098 The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2018 MYLTIP Units and, after the February 4, 2022 measurement date, the 2019 MYLTIP Units) and its distributions on the 2019 MYLTIP Units (prior to the February 4, 2022 measurement date) and 2020 - 2022 MYLTIP Units (after the February 1, 2022 issuance date of the 2022 MYLTIP Units) that occurred during the three months ended March 31, 2022: Record Date Payment Date Distributions per OP Unit and LTIP Unit Distributions per MYLTIP Unit March 31, 2022 April 29, 2022 $0.98 $0.098 December 31, 2021 January 28, 2022 $0.98 $0.098 A holder of an OP Unit may present the OP Unit to BPLP for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, BPLP must redeem the OP Unit for cash equal to the then value of a share of Common Stock of BXP. BXP may, in its sole discretion, elect to assume and satisfy the redemption obligation by paying either cash or issuing one share of Common Stock. The value of the OP Units (other than OP Units owned by BXP), and LTIP Units (including the 2012 OPP Units and 2013 - 2020 MYLTIP Units), assuming in each case that all conditions had been met for the conversion thereof, had all of such units been redeemed at March 31, 2023 was approximately $1.1 billion based on the last reported price of a share of Common Stock on the New York Stock Exchange of $54.12 per share on March 31, 2023. Noncontrolling Interests—Property Partnerships The noncontrolling interests in property partnerships consist of the outside equity interests in ventures that are consolidated with the financial results of the Company because the Company exercises control over the entities that own the properties. The equity interests in these ventures that are not owned by the Company, totaling approximately $1.6 billion and $1.5 billion a t March 31, 2023 and December 31, 2022, respectively, are included in Noncontrolling Interests—Property Partnerships on the accompanying Consolidated Balance Sheets.

Stockholders' Equity _ Partners

Stockholders' Equity / Partners' Capital	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Stockholders' Equity / Partners' Capital	9. Stockholders’ Equity / Partners’ Capital As of March 31, 2023, BXP had 156,829,793 shares of Common Stock outstanding. As of March 31, 2023, BXP owned 1,754,892 general partnership units and 155,074,901 limited partnership units in BPLP. On May 22, 2020, BXP renewed its “at the market” (“ATM”) stock offering program through which it may sell from time to time up to an aggregate of $600.0 million of its Common Stock through sales agents over a three-year period. Under the ATM stock offering program, BXP may also engage in forward sale transactions with affiliates of certain sales agents for the sale of its Common Stock on a forward basis. This program replaced BXP’s prior $600.0 million ATM stock offering program that was scheduled to expire on June 2, 2020. BXP intends to use the net proceeds from any offering for general business purposes, which may include investment opportunities and debt reduction. No shares of Common Stock have been issued under this ATM stock offering program. During the three months ended March 31, 2023, BXP did not issue any shares of Common Stock upon the exercise of options to purchase Common Stock. As a result of the exercise period ending on February 1, 2023, 49,359 options were forfeited. During the three months ended March 31, 2023, BXP issued 5,188 shares of Common Stock in connection with the redemption of an equal number of redeemable OP Units from limited partners. The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared in 2023 and during the three months ended March 31, 2022: Record Date Payment Date Dividend (Per Share) Distribution (Per Unit) March 31, 2023 April 28, 2023 $0.98 $0.98 December 30, 2022 January 30, 2023 $0.98 $0.98 March 31, 2022 April 29, 2022 $0.98 $0.98 December 31, 2021 January 28, 2022 $0.98 $0.98

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	10. Segment Information The following tables present reconciliations of Net Income Attributable to Boston Properties, Inc. to the Company’s share of Net Operating Income and Net Income Attributable to Boston Properties Limited Partnership to the Company’s share of Net Operating Income for the three months ended March 31, 2023 and 2022. BXP Three months ended March 31, 2023 2022 (in thousands) Net income attributable to Boston Properties, Inc. $ 77,890 $ 143,047 Add: Noncontrolling interest—common units of the Operating Partnership 9,078 16,361 Noncontrolling interests in property partnerships 18,660 17,549 Interest expense 134,207 101,228 Net operating income from unconsolidated joint ventures 40,756 37,321 Depreciation and amortization expense 208,734 177,624 Transaction costs 911 — Payroll and related costs from management services contracts 5,235 4,065 General and administrative expense 55,802 43,194 Less: Net operating income attributable to noncontrolling interests in property partnerships 47,097 47,055 Unrealized gain on non-real estate investment 259 — Gains (losses) from investments in securities 1,665 (2,262) Interest and other income (loss) 10,941 1,228 Gains on sales of real estate — 22,701 Income (loss) from unconsolidated joint ventures (7,569) 2,189 Direct reimbursements of payroll and related costs from management services contracts 5,235 4,065 Development and management services revenue 8,980 5,831 Company’s share of Net Operating Income $ 484,665 $ 459,582 BPLP Three months ended March 31, 2023 2022 (in thousands) Net income attributable to Boston Properties Limited Partnership $ 88,830 $ 161,829 Add: Noncontrolling interests in property partnerships 18,660 17,549 Interest expense 134,207 101,228 Net operating income from unconsolidated joint ventures 40,756 37,321 Depreciation and amortization expense 206,872 175,886 Transaction costs 911 — Payroll and related costs from management services contracts 5,235 4,065 General and administrative expense 55,802 43,194 Less: Net operating income attributable to noncontrolling interests in property partnerships 47,097 47,055 Unrealized gain on non-real estate investment 259 — Gains (losses) from investments in securities 1,665 (2,262) Interest and other income (loss) 10,941 1,228 Gains on sales of real estate — 23,384 Income (loss) from unconsolidated joint ventures (7,569) 2,189 Direct reimbursements of payroll and related costs from management services contracts 5,235 4,065 Development and management services revenue 8,980 5,831 Company’s share of Net Operating Income $ 484,665 $ 459,582 Net operating income (“NOI”) is a non-GAAP financial measure equal to net income attributable to Boston Properties, Inc. and net income attributable to Boston Properties Limited Partnership, as applicable, the most directly comparable GAAP financial measures, plus (1) net income attributable to noncontrolling interests, interest expense, depreciation and amortization expense, transaction costs, payroll and related costs from management services contracts and corporate general and administrative expense less (2) unrealized gain on non-real estate investment, gains (losses) from investments in securities, interest and other income (loss), gains on sales of real estate, income (loss) from unconsolidated joint ventures, direct reimbursements of payroll and related costs from management services contracts and development and management services revenue. The Company believes NOI is useful to investors as a performance measure and believes it provides useful information to investors regarding its results of operations and financial condition because, when compared across periods, it reflects the impact on operations from trends in occupancy rates, rental rates, operating costs and acquisition and development activity on an unleveraged basis, providing perspective not immediately apparent from net income attributable to Boston Properties, Inc. and net income attributable to Boston Properties Limited Partnership. For example, interest expense is not necessarily linked to the operating performance of a real estate asset and is often incurred at the corporate level as opposed to the property level. Similarly, interest expense may be incurred at the property level even though the financing proceeds may be used at the corporate level (e.g., used for other investment activity). In addition, depreciation and amortization expense, because of historical cost accounting and useful life estimates, may distort operating performance measures at the property level. NOI presented by the Company may not be comparable to NOI reported by other REITs or real estate companies that define NOI differently. The Company’s internal reporting utilizes its share of NOI, which includes its share of NOI from consolidated and unconsolidated joint ventures, which is a non-GAAP financial measure that is calculated as the consolidated amount, plus the Company’s share of the amount from the Company’s unconsolidated joint ventures (calculated based upon the Company’s economic percentage ownership interest and, in some cases, after priority allocations), less the Company’s partners’ share of the amount from the Company’s consolidated joint ventures (calculated based upon the partners’ economic percentage ownership interests and, in some cases, after priority allocations, income allocation to private REIT shareholders and their share of fees due to the Company). The Company’s share of NOI from unconsolidated joint ventures, as defined above, also does not include its share of losses from early extinguishment of debt from unconsolidated joint ventures and unrealized loss on derivative instruments, both of which are included within Income (Loss) From Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations. Management utilizes its share of NOI in assessing its performance as the Company has several significant joint ventures and, in some cases, the Company exercises significant influence over, but does not control, the joint venture, in which case GAAP requires that the Company account for the joint venture entity using the equity method of accounting and the Company does not consolidate it for financial reporting purposes. In other cases, GAAP requires that the Company consolidate the venture even though the Company’s partner(s) owns a significant percentage interest. As a result, the presentations of the Company’s share of NOI should not be considered a substitute for, and should only be considered together with and as a supplement to, the Company’s financial information presented in accordance with GAAP. Asset information by segment is not reported because the Company does not use this measure to assess performance. Therefore, depreciation and amortization expense is not allocated among segments. Interest expense, depreciation and amortization expense, transaction costs, payroll and related costs from management services contracts, corporate general and administrative expense, unrealized gain on non-real estate investment, gains (losses) from investments in securities, interest and other income (loss), gains on sales of real estate, income (loss) from unconsolidated joint ventures, direct reimbursements of payroll and related costs from management services contracts and development and management services revenue are not included in NOI and are provided as reconciling items to the Company’s reconciliations of its share of NOI to net income. The Company’s segments are based on the Company’s method of internal reporting which classifies its operations by geographic area. The Company’s segments by geographic area are Boston, Los Angeles, New York, San Francisco, Seattle and Washington, DC. The Company also presents information for each segment by property type, including Premier Workplace (which includes office, life sciences and retail), Residential and Hotel. Information by geographic area and property type (dollars in thousands): For the three months ended March 31, 2023: Boston Los Angeles New York San Francisco Seattle Washington, DC Total Rental Revenue: (1) Premier Workplace $ 269,951 $ — $ 258,192 $ 136,093 $ 14,258 $ 90,664 $ 769,158 Residential 4,049 — — 3,642 — 4,035 11,726 Hotel 8,101 — — — — — 8,101 Total 282,101 — 258,192 139,735 14,258 94,699 788,985 % of Grand Totals 35.76 % — % 32.72 % 17.71 % 1.81 % 12.00 % 100.00 % Rental Expenses: Premier Workplace 100,049 — 102,485 46,085 2,960 34,266 285,845 Residential 1,552 — — 2,173 — 1,738 5,463 Hotel 6,671 — — — — — 6,671 Total 108,272 — 102,485 48,258 2,960 36,004 297,979 % of Grand Totals 36.34 % — % 34.39 % 16.20 % 0.99 % 12.08 % 100.00 % Net operating income $ 173,829 $ — $ 155,707 $ 91,477 $ 11,298 $ 58,695 $ 491,006 % of Grand Totals 35.41 % — % 31.71 % 18.63 % 2.30 % 11.95 % 100.00 % Less: Net operating income attributable to noncontrolling interests in property partnerships (10,817) — (36,280) — — — (47,097) Add: Company’s share of net operating income from unconsolidated joint ventures 8,577 13,225 3,650 3,464 1,846 9,994 40,756 Company’s share of net operating income $ 171,589 $ 13,225 $ 123,077 $ 94,941 $ 13,144 $ 68,689 $ 484,665 % of Grand Totals 35.41 % 2.73 % 25.39 % 19.59 % 2.71 % 14.17 % 100.00 % _______________ (1) Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations. For the three months ended March 31, 2022: Boston Los Angeles New York San Francisco Seattle Washington, DC Total Rental Revenue: (1) Premier Workplace $ 242,078 $ — $ 256,870 $ 132,375 $ — $ 95,565 $ 726,888 Residential 3,596 — — 2,391 — 6,979 12,966 Hotel 4,557 — — — — — 4,557 Total 250,231 — 256,870 134,766 — 102,544 744,411 % of Grand Totals 33.61 % — % 34.51 % 18.10 % — % 13.78 % 100.00 % Rental Expenses: Premier Workplace 90,528 — 96,340 43,408 — 33,547 263,823 Residential 1,437 — — 1,868 — 3,127 6,432 Hotel 4,840 — — — — — 4,840 Total 96,805 — 96,340 45,276 — 36,674 275,095 % of Grand Totals 35.19 % — % 35.02 % 16.46 % — % 13.33 % 100.00 % Net operating income $ 153,426 $ — $ 160,530 $ 89,490 $ — $ 65,870 $ 469,316 % of Grand Totals 32.69 % — % 34.21 % 19.07 % — % 14.03 % 100.00 % Less: Net operating income attributable to noncontrolling interests in property partnerships (11,735) — (35,320) — — — (47,055) Add: Company’s share of net operating income (loss) from unconsolidated joint ventures 9,693 13,757 (156) 3,181 1,955 8,891 37,321 Company’s share of net operating income $ 151,384 $ 13,757 $ 125,054 $ 92,671 $ 1,955 $ 74,761 $ 459,582 % of Grand Totals 32.94 % 2.99 % 27.21 % 20.16 % 0.43 % 16.27 % 100.00 % _______________ (1) Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Earnings Per Share _ Common Uni

Earnings Per Share / Common Unit	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Earnings Per Share / Common Unit	11. Earnings Per Share / Common Unit BXP The following table provides a reconciliation of both the net income attributable to Boston Properties, Inc. and the number of common shares used in the computation of basic earnings per share (“EPS”), which is calculated by dividing net income attributable to Boston Properties, Inc. by the weighted-average number of common shares outstanding during the period. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are also participating securities. As such, unvested restricted common stock of BXP and BPLP’s LTIP Units, 2012 OPP Units and MYLTIP Units are considered participating securities. Participating securities are included in the computation of basic EPS of BXP using the two-class method. Participating securities are included in the computation of diluted EPS of BXP using the if-converted method if the impact is dilutive. Because the 2012 OPP Units and 2013 - 2020 MYLTIP Units required, and the 2021 - 2023 MYLTIP Units require, BXP to outperform absolute and/or relative return thresholds, unless such thresholds have been met by the end of the applicable reporting period, BXP excludes such units from the diluted EPS calculation. Other potentially dilutive common shares, including stock options, restricted stock and other securities of BPLP that are exchangeable for BXP’s Common Stock, and the related impact on earnings, are considered when calculating diluted EPS. Three months ended March 31, 2023 Income Shares Per Share (in thousands, except for per share amounts) Basic Earnings: Net income attributable to Boston Properties, Inc. $ 77,890 156,803 $ 0.50 Effect of Dilutive Securities: Stock Based Compensation — 240 — Diluted Earnings: Net income attributable to Boston Properties, Inc. $ 77,890 157,043 $ 0.50 Three months ended March 31, 2022 Income Shares Per Share (in thousands, except for per share amounts) Basic Earnings: Net income attributable to Boston Properties, Inc. $ 143,047 156,650 $ 0.91 Effect of Dilutive Securities: Stock Based Compensation — 354 — Diluted Earnings: Net income attributable to Boston Properties, Inc. $ 143,047 157,004 $ 0.91 BPLP The following table provides a reconciliation of both the net income attributable to Boston Properties Limited Partnership and the number of common units used in the computation of basic earnings per common unit, which is calculated by dividing net income attributable to Boston Properties Limited Partnership by the weighted-average number of common units outstanding during the period. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are also participating securities. As such, unvested restricted common stock of BXP and BPLP’s LTIP Units, 2012 OPP Units and MYLTIP Units are considered participating securities. Participating securities are included in the computation of basic earnings per common unit using the two-class method. Participating securities are included in the computation of diluted earnings per common unit using the if-converted method if the impact is dilutive. Because the 2012 OPP Units and 2013 - 2020 MYLTIP Units required, and the 2021 - 2023 MYLTIP Units require, BXP to outperform absolute and/or relative return thresholds, unless such thresholds have been met by the end of the applicable reporting period, BPLP excludes such units from the diluted earnings per common unit calculation. Other potentially dilutive common units and the related impact on earnings are considered when calculating diluted earnings per common unit. Included in the number of units (the denominator) below are approximately 17,849,000 and 17,626,000 redeemable common units for the three months ended March 31, 2023 and 2022, respectively. Three months ended March 31, 2023 Income Units Per Unit (in thousands, except for per unit amounts) Basic Earnings: Net income attributable to Boston Properties Limited Partnership $ 88,830 174,652 $ 0.51 Effect of Dilutive Securities: Stock Based Compensation — 240 — Diluted Earnings: Net income attributable to Boston Properties Limited Partnership $ 88,830 174,892 $ 0.51 Three months ended March 31, 2022 Income Units Per Unit (in thousands, except for per unit amounts) Basic Earnings: Net income attributable to Boston Properties Limited Partnership common unitholders $ 161,829 174,276 $ 0.93 Effect of Dilutive Securities: Stock Based Compensation — 354 — Diluted Earnings: Net income attributable to Boston Properties Limited Partnership $ 161,829 174,630 $ 0.93

Stock Option and Incentive Plan

Stock Option and Incentive Plan	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock Option and Incentive Plan	12. Stock Option and Incentive Plan On January 25, 2023, BXP’s Compensation Committee approved the grant of 2023 MYLTIP awards under the Boston Properties, Inc. 2021 Stock Incentive Plan (the “2021 Plan”) to certain executive officers of BXP, effective February 7, 2023. The 2023 MYLTIP awards consist of two, equally weighted (50% each) components that utilize BXP’s TSR over a three-year measurement period as the performance metric. Total earned awards under the 2023 MYLTIP, if any, will equal the sum of the number of LTIP Units earned under the first and second components and will range from zero to a maximum of 322,053 LTIP Units with a target of approximately 161,026 LTIP Units and linear interpolation between zero and maximum. Earned awards (if any) will vest 100% on February 6, 2026, but, in general, may not be converted, redeemed, sold or otherwise transferred for one additional year thereafter. The 2023 MYLTIP awards are in the form of LTIP Units issued on the grant date, and they are subject to forfeiture to the extent awards are not earned. Prior to the performance measurement date holders of the 2023 MYLTIP Units are only entitled to one-tenth (10%) of the regular quarterly distributions payable on common partnership units. Following the completion of the three On February 3, 2023, the measurement period for the Company’s 2020 MYLTIP awards ended and, based on BXP’s relative TSR performance, the final payout was determined to be 50% of target, or an aggregate of approximately $3.8 million (after giving effect to employee separations). As a result, an aggregate of 152,460 2020 MYLTIP Units that had been previously granted were automatically forfeited. During the three months ended March 31, 2023, BXP issued 66,634 shares of restricted common stock and BPLP issued 403,446 LTIP Units and 322,053 2023 MYLTIP Units to employees and non-employee directors under

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On April 21, 2023, a joint venture in which BXP has a 50% interest exercised an option to extend by one year the maturity date of its $252.6 million construction loan collateralized by its 7750 Wisconsin Avenue property. The completed 734,000 square foot build-to-suit, premier workplace is located in Bethesda, Maryland and is 100% leased to an affiliate of Marriott International, Inc. Effective June 1, 2023, the financing will bear interest at a variable rate equal to Term SOFR plus 1.35% per annum and will now mature on April 26, 2024, with a one-year extension option, subject to certain conditions. On April 29, 2023, the Company completed and fully placed in-service 2100 Pennsylvania Avenue, a premier workplace project with approximately 480,000 net rentable square feet located in Washington, DC. On May 02, 2023, BPLP executed interest rate swaps in notional amounts aggregating $1.2 billion. These interest rate swaps were entered into to fix Term SOFR under for BPLP’s 2023 Unsecured Term Loan at a weighted-average rate of 4.6420% for the period commencing on May 4, 2023 and ending on May 16, 2024. Based on BPLP’s credit rating as of May 2, 2023, the interest rate for the 2023 Unsecured Term Loan would be 5.592% (See Note 6).

Comprehensive Text Block List (

Comprehensive Text Block List (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	BXP does not have any other significant assets, liabilities or operations, other than its investment in BPLP, nor does it have employees of its own. BPLP, not BXP, generally executes all significant business relationships other than transactions involving securities of BXP. All majority-owned subsidiaries and joint ventures over which the Company has financial and operating control and variable interest entities (“VIEs”) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income.The accompanying interim financial statements are unaudited; however, the financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information and in conjunction with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting solely of normal recurring matters) necessary for a fair statement of the financial statements for these interim periods have been included. The results of operations for the interim periods are not necessarily indicative of the results to be obtained for other interim periods or for the full fiscal year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosure required by GAAP.  These financial statements should be read in conjunction with the Company’s financial statements and notes thereto contained in the Company’s Annual Report in the Company’s Form 10-K for its fiscal year ended December 31, 2022.
Consolidation, Variable Interest Entity, Policy	Consolidated VIEs are those for which the Company is considered to be the primary beneficiary of a VIE. The primary beneficiary is the entity that has a controlling financial interest in the VIE, which is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and (2) the obligation to absorb losses or the right to receive the returns from the VIE that could potentially be significant to the VIE.

Summary Of Significant Accoun_2

Summary Of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Use of Estimates in the Preparation of Financial Statements	The Company bases its estimates on historical experience and on various other assumptions that it considers to be reasonable under the circumstances, including the impact of extraordinary events such as the coronavirus (“COVID-19”) pandemic, the results of which form the basis for making significant judgments about the carrying values of assets and liabilities, assessments of future collectability, and other areas of the financial statements that are impacted by the use of estimates. Actual results may differ from these estimates under different assumptions or conditions.

Summary Of Significant Accoun_3

Summary Of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
Summary Of Significant Accounting Policies [Line Items]
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]	The Company follows the authoritative guidance for fair value measurements when valuing its financial instruments for disclosure purposes. The table below presents for March 31, 2023 and December 31, 2022, the financial instruments that are being valued for disclosure purposes as well as the Level at which they are categorized (as defined in Accounting Standards Codification (“ASC”) 820 “Fair Value Measurements and Disclosures”). Financial Instrument Level Unsecured senior notes (1) Level 1 Related party note receivable Level 3 Sales-type lease receivable Level 3 Mortgage notes payable Level 3 Unsecured line of credit Level 3 Unsecured term loan Level 3 _______________ (1) If trading volume for the period is low, the valuation could be categorized as Level 2. Because the Company’s valuations of its financial instruments are based on the above Levels and involve the use of estimates, the actual fair values of its financial instruments may differ materially from those estimates.
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the aggregate carrying value of the Company’s related party note receivable, net, sales-type lease receivable, net, mortgage notes payable, net, unsecured senior notes, net, unsecured line of credit and unsecured term loan, net and the Company’s corresponding estimate of fair value as of March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 December 31, 2022 Carrying Estimated Carrying Estimated Related party note receivable, net $ 78,544 $ 79,472 $ 78,576 $ 79,220 Sales-type lease receivable, net 13,028 13,086 12,811 13,045 Total $ 91,572 $ 92,558 $ 91,387 $ 92,265 Mortgage notes payable, net $ 3,273,553 $ 2,826,826 $ 3,272,368 $ 2,744,479 Unsecured senior notes, net 10,240,967 8,759,487 10,237,968 9,135,512 Unsecured line of credit — — — — Unsecured term loan, net 1,194,916 1,200,000 730,000 730,000 Total $ 14,709,436 $ 12,786,313 $ 14,240,336 $ 12,609,991

Real Estate (Tables)

Real Estate (Tables)	3 Months Ended
	Mar. 31, 2023
Real Estate Properties [Line Items]
Schedule of Real Estate Properties	BXP Real estate consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 December 31, 2022 Land $ 5,189,287 $ 5,189,811 Right of use assets - finance leases 237,503 237,510 Right of use assets - operating leases 166,699 167,351 Land held for future development (1) 626,137 721,501 Buildings and improvements 15,783,962 15,820,724 Tenant improvements 3,291,322 3,200,743 Furniture, fixtures and equipment 50,242 50,310 Construction in progress 618,770 406,574 Total 25,963,922 25,794,524 Less: Accumulated depreciation (6,424,547) (6,298,082) $ 19,539,375 $ 19,496,442 _______________ (1) Includes pre-development costs.
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Schedule of Real Estate Properties	BPLP Real estate consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 December 31, 2022 Land $ 5,094,578 $ 5,095,102 Right of use assets - finance leases 237,503 237,510 Right of use assets - operating leases 166,699 167,351 Land held for future development (1) 626,137 721,501 Buildings and improvements 15,512,406 15,547,919 Tenant improvements 3,291,322 3,200,743 Furniture, fixtures and equipment 50,242 50,310 Construction in progress 618,770 406,574 Total 25,597,657 25,427,010 Less: Accumulated depreciation (6,306,326) (6,180,474) $ 19,291,331 $ 19,246,536 _______________ (1) Includes pre-development costs.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Lessor, Lease, Description [Line Items]
Operating Lease, Lease Income [Table Text Block]	The following table summarizes the components of lease revenue recognized for its operating and sales-type leases during the three months ended March 31, 2023 and 2022 included within the Company's Consolidated Statements of Operations (in thousands): Three months ended March 31, Lease Revenue 2023 2022 Fixed contractual payments $ 621,646 $ 599,607 Variable lease payments 135,003 118,513 Sales-type lease income 226 — $ 756,875 $ 718,120
Sales-type Lease, Lease Income	The following table summarizes the components of lease revenue recognized for its operating and sales-type leases during the three months ended March 31, 2023 and 2022 included within the Company's Consolidated Statements of Operations (in thousands): Three months ended March 31, Lease Revenue 2023 2022 Fixed contractual payments $ 621,646 $ 599,607 Variable lease payments 135,003 118,513 Sales-type lease income 226 — $ 756,875 $ 718,120

Investments in Unconsolidated_2

Investments in Unconsolidated Joint Ventures (Tables)	3 Months Ended
	Mar. 31, 2023
Schedule of Equity Method Investments [Line Items]
Investments In Unconsolidated Joint Ventures	The investments in unconsolidated joint ventures consist of the following at March 31, 2023 and December 31, 2022: Carrying Value of Investment (1) Entity Properties Nominal % Ownership March 31, 2023 December 31, 2022 (in thousands) Square 407 Limited Partnership Market Square North 50.00 % $ (6,097) $ (6,198) BP/CRF Metropolitan Square LLC Metropolitan Square 20.00 % (38,782) (37,629) 901 New York, LLC 901 New York Avenue 25.00 % (2) (12,311) (12,493) WP Project Developer LLC Wisconsin Place Land and Infrastructure 33.33 % (3) 31,723 31,971 500 North Capitol Venture LLC 500 North Capitol Street, NW 30.00 % (8,941) (9,185) 501 K Street LLC 1001 6th Street 50.00 % (4) 43,661 42,922 Podium Developer LLC The Hub on Causeway - Podium 50.00 % 45,622 46,839 Residential Tower Developer LLC Hub50House 50.00 % 42,046 45,414 Hotel Tower Developer LLC The Hub on Causeway - Hotel Air Rights 50.00 % 12,582 12,366 Office Tower Developer LLC 100 Causeway Street 50.00 % 59,811 59,716 1265 Main Office JV LLC 1265 Main Street 50.00 % 3,605 3,465 BNY Tower Holdings LLC Dock 72 50.00 % (5) (15,362) (19,921) CA-Colorado Center, LLC Colorado Center 50.00 % 234,635 233,862 7750 Wisconsin Avenue LLC 7750 Wisconsin Avenue 50.00 % 51,549 52,152 BP-M 3HB Venture LLC 3 Hudson Boulevard 25.00 % 115,966 116,397 SMBP Venture LP Santa Monica Business Park 55.00 % 161,786 164,735 Platform 16 Holdings LP Platform 16 55.00 % (6) 171,010 158,109 Gateway Portfolio Holdings LLC Gateway Commons 50.00 % 337,535 324,038 Rosecrans-Sepulveda Partners 4, LLC Beach Cities Media Campus 50.00 % 26,987 27,000 Safeco Plaza REIT LLC Safeco Plaza 33.67 % (7) 68,196 69,785 360 PAS Holdco LLC 360 Park Avenue South 42.21 % (8) 116,828 114,992 PR II/BXP Reston Gateway LLC Reston Next Residential 20.00 % (9) 11,431 11,351 751 Gateway Holdings LLC 751 Gateway 49.00 % 85,430 80,714 200 Fifth Avenue JV LLC 200 Fifth Avenue 26.69 % 114,919 120,083 ABXP Worldgate Investments LLC 13100 and 13150 Worldgate Drive 50.00 % 17,295 N/A $ 1,671,124 $ 1,630,485 _______________ (1) Investments with deficit balances aggregating approximately $81.5 million and $85.4 million at March 31, 2023 and December 31, 2022, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets. (2) The Company’s economic ownership has increased based on the achievement of certain return thresholds. At March 31, 2023 and December 31, 2022, the Company’s economic ownership was approximately 50%. (3) The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project. (4) Under the joint venture agreement for this land parcel, the partner will be entitled to up to two additional payments from the venture based on increases in total entitled square footage of the project in excess of 520,000 square feet and achieving certain project returns at stabilization. (5) This property includes net equity balances from the amenity joint venture. (6) This entity is a VIE (See Note 2). (7) The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. (8) The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 5.837% indirect ownership in the joint venture, and (3) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. The Company’s partners will fund required capital until their aggregate investment is approximately 58% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests. (9) The Company’s partner will fund required capital until its aggregate investment is approximately 80% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.
Schedule Of Balance Sheets Of The Unconsolidated Joint Ventures [Text Block]	The combined summarized balance sheets of the Company’s unconsolidated joint ventures are as follows: March 31, 2023 December 31, 2022 (in thousands) ASSETS Real estate and development in process, net (1) $ 6,649,580 $ 6,537,554 Other assets 755,055 756,786 Total assets $ 7,404,635 $ 7,294,340 LIABILITIES AND MEMBERS’/PARTNERS’ EQUITY Mortgage and notes payable, net $ 4,037,789 $ 4,022,746 Other liabilities (2) 723,660 716,271 Members’/Partners’ equity 2,643,186 2,555,323 Total liabilities and members’/partners’ equity $ 7,404,635 $ 7,294,340 Company’s share of equity $ 1,271,419 $ 1,238,929 Basis differentials (3) 399,705 391,556 Carrying value of the Company’s investments in unconsolidated joint ventures (4) $ 1,671,124 $ 1,630,485 _______________ (1) At March 31, 2023 and December 31, 2022, this amount included right of use assets - finance leases totaling approximately $248.9 million. At March 31, 2023 and December 31, 2022, this amount included right of use assets - operating leases totaling approximately $20.9 million and $21.2 million, respectively. (2) At March 31, 2023 and December 31, 2022, this amount included lease liabilities - finance leases totaling approximately $381.0 million and $382.2 million, respectively. At March 31, 2023 and December 31, 2022, this amount included lease liabilities - operating leases totaling approximately $30.5 million. (3) This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows: March 31, 2023 December 31, 2022 Property (in thousands) Colorado Center $ 301,097 $ 301,820 200 Fifth Avenue 99,381 94,497 Gateway Commons 47,707 47,808 Dock 72 (98,120) (98,980) These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities. (4) Investments with deficit balances aggregating approximately $81.5 million and $85.4 million at March 31, 2023 and December 31, 2022, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.
Statements Of Operations Of The Joint Ventures	The combined summarized statements of operations of the Company’s unconsolidated joint ventures are as follows: Three months ended March 31, 2023 2022 (in thousands) Total revenue (1) $ 151,423 $ 124,491 Expenses Operating 57,206 45,641 Transaction costs 74 — Depreciation and amortization 49,978 44,664 Total expenses 107,258 90,305 Other income (expense) Loss from early extinguishment of debt — (1,327) Interest expense (57,250) (30,373) Unrealized loss on derivative instruments (10,610) — Net income (loss) $ (23,695) $ 2,486 Company’s share of net income (loss) $ (6,902) $ 3,394 Basis differential (2) (667) (1,205) Income (loss) from unconsolidated joint ventures $ (7,569) $ 2,189 _______________ (1) Includes straight-line rent adjustments of approximately $6.3 million and $27.5 million for the three months ended March 31, 2023 and 2022, respectively. (2) Includes straight-line rent adjustments of approximately $0.3 million and $0.1 million for the three months ended March 31, 2023 and 2022, respectively. Also includes net above-/below-market rent adjustments of approximately $0.2 million and $0.1 million for the three months ended March 31, 2023 and 2022, respectively.

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	3 Months Ended
	Mar. 31, 2023
Noncontrolling Interest [Line Items]
Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]	The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared in 2023 and during the three months ended March 31, 2022: Record Date Payment Date Dividend (Per Share) Distribution (Per Unit) March 31, 2023 April 28, 2023 $0.98 $0.98 December 30, 2022 January 30, 2023 $0.98 $0.98 March 31, 2022 April 29, 2022 $0.98 $0.98 December 31, 2021 January 28, 2022 $0.98 $0.98
Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]	The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2019 MYLTIP Units and, after the February 3, 2023 measurement date, the 2020 MYLTIP Units) and its distributions on the 2020 MYLTIP Units (prior to the February 3, 2023 measurement date) and 2021 - 2023 MYLTIP Units (after the February 7, 2023 issuance date of the 2023 MYLTIP Units) that occurred during the three months ended March 31, 2023: Record Date Payment Date Distributions per OP Unit and LTIP Unit Distributions per MYLTIP Unit March 31, 2023 April 28, 2023 $0.98 $0.098 December 30, 2022 January 30, 2023 $0.98 $0.098 The following table presents BPLP’s distributions on the OP Units and LTIP Units (including the 2012 OPP Units, 2013 - 2018 MYLTIP Units and, after the February 4, 2022 measurement date, the 2019 MYLTIP Units) and its distributions on the 2019 MYLTIP Units (prior to the February 4, 2022 measurement date) and 2020 - 2022 MYLTIP Units (after the February 1, 2022 issuance date of the 2022 MYLTIP Units) that occurred during the three months ended March 31, 2022: Record Date Payment Date Distributions per OP Unit and LTIP Unit Distributions per MYLTIP Unit March 31, 2022 April 29, 2022 $0.98 $0.098 December 31, 2021 January 28, 2022 $0.98 $0.098

Stockholders' Equity _ Partne_2

Stockholders' Equity / Partners' Capital (Tables)	3 Months Ended
	Mar. 31, 2023
Class of Stock [Line Items]
Dividends Declared [Table Text Block]	The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared in 2023 and during the three months ended March 31, 2022: Record Date Payment Date Dividend (Per Share) Distribution (Per Unit) March 31, 2023 April 28, 2023 $0.98 $0.98 December 30, 2022 January 30, 2023 $0.98 $0.98 March 31, 2022 April 29, 2022 $0.98 $0.98 December 31, 2021 January 28, 2022 $0.98 $0.98

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Schedule Of Reconciliation Of Net Operating Income To Net Income	BXP Three months ended March 31, 2023 2022 (in thousands) Net income attributable to Boston Properties, Inc. $ 77,890 $ 143,047 Add: Noncontrolling interest—common units of the Operating Partnership 9,078 16,361 Noncontrolling interests in property partnerships 18,660 17,549 Interest expense 134,207 101,228 Net operating income from unconsolidated joint ventures 40,756 37,321 Depreciation and amortization expense 208,734 177,624 Transaction costs 911 — Payroll and related costs from management services contracts 5,235 4,065 General and administrative expense 55,802 43,194 Less: Net operating income attributable to noncontrolling interests in property partnerships 47,097 47,055 Unrealized gain on non-real estate investment 259 — Gains (losses) from investments in securities 1,665 (2,262) Interest and other income (loss) 10,941 1,228 Gains on sales of real estate — 22,701 Income (loss) from unconsolidated joint ventures (7,569) 2,189 Direct reimbursements of payroll and related costs from management services contracts 5,235 4,065 Development and management services revenue 8,980 5,831 Company’s share of Net Operating Income $ 484,665 $ 459,582 BPLP Three months ended March 31, 2023 2022 (in thousands) Net income attributable to Boston Properties Limited Partnership $ 88,830 $ 161,829 Add: Noncontrolling interests in property partnerships 18,660 17,549 Interest expense 134,207 101,228 Net operating income from unconsolidated joint ventures 40,756 37,321 Depreciation and amortization expense 206,872 175,886 Transaction costs 911 — Payroll and related costs from management services contracts 5,235 4,065 General and administrative expense 55,802 43,194 Less: Net operating income attributable to noncontrolling interests in property partnerships 47,097 47,055 Unrealized gain on non-real estate investment 259 — Gains (losses) from investments in securities 1,665 (2,262) Interest and other income (loss) 10,941 1,228 Gains on sales of real estate — 23,384 Income (loss) from unconsolidated joint ventures (7,569) 2,189 Direct reimbursements of payroll and related costs from management services contracts 5,235 4,065 Development and management services revenue 8,980 5,831 Company’s share of Net Operating Income $ 484,665 $ 459,582
Schedule Of Segment Information By Geographic Area And Property Type	Information by geographic area and property type (dollars in thousands): For the three months ended March 31, 2023: Boston Los Angeles New York San Francisco Seattle Washington, DC Total Rental Revenue: (1) Premier Workplace $ 269,951 $ — $ 258,192 $ 136,093 $ 14,258 $ 90,664 $ 769,158 Residential 4,049 — — 3,642 — 4,035 11,726 Hotel 8,101 — — — — — 8,101 Total 282,101 — 258,192 139,735 14,258 94,699 788,985 % of Grand Totals 35.76 % — % 32.72 % 17.71 % 1.81 % 12.00 % 100.00 % Rental Expenses: Premier Workplace 100,049 — 102,485 46,085 2,960 34,266 285,845 Residential 1,552 — — 2,173 — 1,738 5,463 Hotel 6,671 — — — — — 6,671 Total 108,272 — 102,485 48,258 2,960 36,004 297,979 % of Grand Totals 36.34 % — % 34.39 % 16.20 % 0.99 % 12.08 % 100.00 % Net operating income $ 173,829 $ — $ 155,707 $ 91,477 $ 11,298 $ 58,695 $ 491,006 % of Grand Totals 35.41 % — % 31.71 % 18.63 % 2.30 % 11.95 % 100.00 % Less: Net operating income attributable to noncontrolling interests in property partnerships (10,817) — (36,280) — — — (47,097) Add: Company’s share of net operating income from unconsolidated joint ventures 8,577 13,225 3,650 3,464 1,846 9,994 40,756 Company’s share of net operating income $ 171,589 $ 13,225 $ 123,077 $ 94,941 $ 13,144 $ 68,689 $ 484,665 % of Grand Totals 35.41 % 2.73 % 25.39 % 19.59 % 2.71 % 14.17 % 100.00 % _______________ (1) Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations. For the three months ended March 31, 2022: Boston Los Angeles New York San Francisco Seattle Washington, DC Total Rental Revenue: (1) Premier Workplace $ 242,078 $ — $ 256,870 $ 132,375 $ — $ 95,565 $ 726,888 Residential 3,596 — — 2,391 — 6,979 12,966 Hotel 4,557 — — — — — 4,557 Total 250,231 — 256,870 134,766 — 102,544 744,411 % of Grand Totals 33.61 % — % 34.51 % 18.10 % — % 13.78 % 100.00 % Rental Expenses: Premier Workplace 90,528 — 96,340 43,408 — 33,547 263,823 Residential 1,437 — — 1,868 — 3,127 6,432 Hotel 4,840 — — — — — 4,840 Total 96,805 — 96,340 45,276 — 36,674 275,095 % of Grand Totals 35.19 % — % 35.02 % 16.46 % — % 13.33 % 100.00 % Net operating income $ 153,426 $ — $ 160,530 $ 89,490 $ — $ 65,870 $ 469,316 % of Grand Totals 32.69 % — % 34.21 % 19.07 % — % 14.03 % 100.00 % Less: Net operating income attributable to noncontrolling interests in property partnerships (11,735) — (35,320) — — — (47,055) Add: Company’s share of net operating income (loss) from unconsolidated joint ventures 9,693 13,757 (156) 3,181 1,955 8,891 37,321 Company’s share of net operating income $ 151,384 $ 13,757 $ 125,054 $ 92,671 $ 1,955 $ 74,761 $ 459,582 % of Grand Totals 32.94 % 2.99 % 27.21 % 20.16 % 0.43 % 16.27 % 100.00 % _______________ (1) Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Earnings Per Share _ Common U_2

Earnings Per Share / Common Unit (Tables)	3 Months Ended
	Mar. 31, 2023
Entity Information [Line Items]
Computation Of Basic And Diluted Earnings Per Share / Unit	Three months ended March 31, 2023 Income Shares Per Share (in thousands, except for per share amounts) Basic Earnings: Net income attributable to Boston Properties, Inc. $ 77,890 156,803 $ 0.50 Effect of Dilutive Securities: Stock Based Compensation — 240 — Diluted Earnings: Net income attributable to Boston Properties, Inc. $ 77,890 157,043 $ 0.50 Three months ended March 31, 2022 Income Shares Per Share (in thousands, except for per share amounts) Basic Earnings: Net income attributable to Boston Properties, Inc. $ 143,047 156,650 $ 0.91 Effect of Dilutive Securities: Stock Based Compensation — 354 — Diluted Earnings: Net income attributable to Boston Properties, Inc. $ 143,047 157,004 $ 0.91
Boston Properties Limited Partnership
Entity Information [Line Items]
Computation Of Basic And Diluted Earnings Per Share / Unit	Three months ended March 31, 2023 Income Units Per Unit (in thousands, except for per unit amounts) Basic Earnings: Net income attributable to Boston Properties Limited Partnership $ 88,830 174,652 $ 0.51 Effect of Dilutive Securities: Stock Based Compensation — 240 — Diluted Earnings: Net income attributable to Boston Properties Limited Partnership $ 88,830 174,892 $ 0.51 Three months ended March 31, 2022 Income Units Per Unit (in thousands, except for per unit amounts) Basic Earnings: Net income attributable to Boston Properties Limited Partnership common unitholders $ 161,829 174,276 $ 0.93 Effect of Dilutive Securities: Stock Based Compensation — 354 — Diluted Earnings: Net income attributable to Boston Properties Limited Partnership $ 161,829 174,630 $ 0.93

Organization (Details)

Organization (Details) ft² in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023 ft² Real_Estate_Properties yr shares	Dec. 31, 2022
Real Estate Properties [Line Items]
Restriction on redemption of OP units from date of issuance (years) | yr	1
One OP unit is equivalent to one share of Common Stock (in shares) | shares	1
OP unit conversion rate (in shares) | shares	1
2012 OPP Units and Vested MYLTIPs
Real Estate Properties [Line Items]
Vesting Period	3 years
Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties	15
Net Rentable Area (in sf) | ft²	4
Commercial Real Estate Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties	192
Net Rentable Area (in sf) | ft²	54.5
Office and Life Sciences Building [Member]
Real Estate Properties [Line Items]
Number of real estate properties	171
Office and Life Sciences Building [Member] | Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties	12
Retail Site [Member]
Real Estate Properties [Line Items]
Number of real estate properties	14
Retail Site [Member] | Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties	2
Residential Building
Real Estate Properties [Line Items]
Number of real estate properties	6
Residential Building | Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties	1
Hotel [Member]
Real Estate Properties [Line Items]
Number of real estate properties	1
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
General and limited partnership interest in the operating partnership (percent)	89.40%	89.60%

Summary Of Significant Accoun_4

Summary Of Significant Accounting Policies (Narrative) (Details)	Mar. 31, 2023
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	7
Variable Interest Entity, Primary Beneficiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	6
Commercial Real Estate Properties [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	5

Summary Of Significant Accoun_5

Summary Of Significant Accounting Policies (Carrying Value Of Indebtedness And Corresponding Estimate Of Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable, net	$ 78,544	$ 78,576
Sales-type lease receivable, net	13,028	12,811
Mortgage notes payable, net	3,273,553	3,272,368
Unsecured senior notes, net	10,240,967	10,237,968
Unsecured line of credit	0	0
Unsecured term loan, net	1,194,916	730,000
Carrying Amount [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable, net	78,544	78,576
Sales-type lease receivable, net	13,028	12,811
Total	91,572	91,387
Mortgage notes payable, net	3,273,553	3,272,368
Unsecured senior notes, net	10,240,967	10,237,968
Unsecured line of credit	0	0
Unsecured term loan, net	1,194,916	730,000
Total	14,709,436	14,240,336
Estimated Fair Value [Member]
Summary Of Significant Accounting Policies [Line Items]
Related party note receivable, net	79,472	79,220
Sales-type lease receivable, net	13,086	13,045
Total	92,558	92,265
Mortgage notes payable, net	2,826,826	2,744,479
Unsecured senior notes, net	8,759,487	9,135,512
Unsecured line of credit	0	0
Unsecured term loan, net	1,200,000	730,000
Total	$ 12,786,313	$ 12,609,991

Real Estate Schedule of Real Es

Real Estate Schedule of Real Estate Properties (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
Real Estate Properties [Line Items]
Land		$ 5,189,287	$ 5,189,811
Right-of-use assets - finance leases		237,503	237,510
Right of use assets - operating leases		166,699	167,351
Land held for future development	[1]	626,137	721,501
Buildings and improvements		15,783,962	15,820,724
Tenant improvements		3,291,322	3,200,743
Furniture, Fixtures and Equipment		50,242	50,310
Construction in progress		618,770	406,574
Total		25,963,922	25,794,524
Less: accumulated depreciation		(6,424,547)	(6,298,082)
Total real estate		19,539,375	19,496,442
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Land		5,094,578	5,095,102
Right-of-use assets - finance leases		237,503	237,510
Right of use assets - operating leases		166,699	167,351
Land held for future development	[1]	626,137	721,501
Buildings and improvements		15,512,406	15,547,919
Tenant improvements		3,291,322	3,200,743
Furniture, Fixtures and Equipment		50,242	50,310
Construction in progress		618,770	406,574
Total		25,597,657	25,427,010
Less: accumulated depreciation		(6,306,326)	(6,180,474)
Total real estate		$ 19,291,331	$ 19,246,536
[1]Includes pre-development costs.

Real Estate (Narrative) (Detail

Real Estate (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) ft²	Mar. 31, 2022 USD ($)	Jan. 30, 2023 ft²	Jan. 05, 2023 ft²
Real Estate Properties [Line Items]
Depreciation and amortization | $	$ 208,734	$ 177,624
Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf)	4,000,000
290 Binney
Real Estate Properties [Line Items]
Net Rentable Area (in sf)				566,000
Leased percentage				100%
300 Binney Street
Real Estate Properties [Line Items]
Net Rentable Area (in sf)			195,000
Depreciation and amortization | $	$ 11,000
300 Binney Street | Construction in Progress
Real Estate Properties [Line Items]
Net Rentable Area (in sf)			236,000
Leased percentage			100%

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Fixed contractual payments	$ 621,646	$ 599,607
Variable lease payments	135,003	118,513
Sales-type lease income	226	0
Lease	$ 756,875	$ 718,120

Investments in Unconsolidated_3

Investments in Unconsolidated Joint Ventures (Investments in Unconsolidated Joint Ventures) (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2023 USD ($) ft² payments	Dec. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
Other Liabilities		$ (465,276)	$ (450,918)
Investments in unconsolidated joint ventures		1,752,617	1,715,911
Investments In Affiliates Subsidiaries Associates And Joint Ventures net	[1]	1,671,124	1,630,485
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Other Liabilities		$ (81,500)	(85,400)
Square 407 Limited Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Market Square North
Ownership Percentage		50%
Other Liabilities	[1]	$ (6,097)	(6,198)
BP/CRF Metropolitan Square LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Metropolitan Square
Ownership Percentage		20%
Other Liabilities	[1]	$ (38,782)	(37,629)
901 New York Avenue LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		901 New York Avenue
Ownership Percentage	[2]	25%
Other Liabilities	[1]	$ (12,311)	$ (12,493)
901 New York Avenue LLC (economic ownership) [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		50%	50%
WP Project Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Wisconsin Place Land and Infrastructure
Ownership Percentage	[3]	33.33%
Investments in unconsolidated joint ventures	[1]	$ 31,723	$ 31,971
500 North Capitol Venture LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		500 North Capitol Street, NW
Ownership Percentage		30%
Other Liabilities	[1]	$ (8,941)	(9,185)
501 K Street LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		1001 6th Street
Ownership Percentage	[4]	50%
Investments in unconsolidated joint ventures	[1]	$ 43,661	42,922
Potential additonal payments to joint venture partner | payments		2
Minimum square footage to make a potential additional payment to joint venture partner (in sqft) | ft²		520,000
Podium Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		The Hub on Causeway - Podium
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 45,622	46,839
Residential Tower Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Hub50House
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 42,046	45,414
Hotel Tower Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		The Hub on Causeway - Hotel Air Rights
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 12,582	12,366
Office Tower Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 59,811	59,716
Office Tower Developer LLC
Schedule of Equity Method Investments [Line Items]
Properties		100 Causeway Street
1265 Main Office JV LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		1265 Main Street
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 3,605	3,465
BNY Tower Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Dock 72
Ownership Percentage	[5]	50%
Other Liabilities	[1]	$ 15,362	19,921
CA-Colorado Center LLC[Member]
Schedule of Equity Method Investments [Line Items]
Properties		Colorado Center
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 234,635	233,862
7750 Wisconsin Avenue LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		7750 Wisconsin Avenue
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 51,549	52,152
BP-M 3HB Venture LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		3 Hudson Boulevard
Ownership Percentage		25%
Investments in unconsolidated joint ventures	[1]	$ 115,966	116,397
SMBP Venture LP [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Santa Monica Business Park
Ownership Percentage		55%
Investments in unconsolidated joint ventures	[1]	$ 161,786	164,735
Platform 16 Holdings LP [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Platform 16
Ownership Percentage	[6]	55%
Investments in unconsolidated joint ventures	[1]	$ 171,010	158,109
Gateway Portfolio Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Properties		Gateway Commons
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 337,535	324,038
Rosecrans-Sepulveda Partners 4, LLC
Schedule of Equity Method Investments [Line Items]
Properties		Beach Cities Media Campus
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 26,987	27,000
Entity Owning Land And Infrastructure Of Project [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		33.33%
Safeco Plaza REIT LLC
Schedule of Equity Method Investments [Line Items]
Properties		Safeco Plaza
Ownership Percentage	[7]	33.67%
Investments in unconsolidated joint ventures	[1]	$ 68,196	69,785
Safeco Plaza REIT LLC | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		33%
360 PAS Holdco LLC
Schedule of Equity Method Investments [Line Items]
Properties		360 Park Avenue South
Ownership Percentage	[8]	42.21%
Investments in unconsolidated joint ventures	[1]	$ 116,828	114,992
360 PAS Holdco LLC | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		35.79%
360 PAS Holdco LLC | Joint Venture Partner [Member] | Scenario, Plan
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		58%
Safeco Partner Entity One [Member] | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		1%
Safeco Partner Entity Two | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		1%
360 PAS Holdco LLC (indirect ownership) | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		5.837%
360 Park Avenue South Partners Entity | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		1%
360 Park Avenue South Partners Entity Two | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		1%
PR II BXP Reston Gateway LLC
Schedule of Equity Method Investments [Line Items]
Properties		Reston Next Residential
Ownership Percentage	[9]	20%
Investments in unconsolidated joint ventures	[1]	$ 11,431	11,351
PR II BXP Reston Gateway LLC | Joint Venture Partner [Member] | Scenario, Plan
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		80%
751 Gateway Holdings LLC
Schedule of Equity Method Investments [Line Items]
Properties		751 Gateway
Ownership Percentage		49%
Investments in unconsolidated joint ventures	[1]	$ 85,430	80,714
200 Fifth Avenue JV LLC
Schedule of Equity Method Investments [Line Items]
Properties		200 Fifth Avenue
Ownership Percentage		26.69%
Investments in unconsolidated joint ventures	[1]	$ 114,919	$ 120,083
ABXP Worldgate Investments LLC
Schedule of Equity Method Investments [Line Items]
Properties		13100 and 13150 Worldgate Drive
Ownership Percentage		50%
Investments in unconsolidated joint ventures	[1]	$ 17,295
[1]Investments with deficit balances aggregating approximately $81.5 million and $85.4 million at March 31, 2023 and December 31, 2022, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.[2]The Company’s economic ownership has increased based on the achievement of certain return thresholds. At March 31, 2023 and December 31, 2022, the Company’s economic ownership was approximately 50%.[3]The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project.[4]Under the joint venture agreement for this land parcel, the partner will be entitled to up to two additional payments from the venture based on increases in total entitled square footage of the project in excess of 520,000 square feet and achieving certain project returns at stabilization.[5]This property includes net equity balances from the amenity joint venture.[6]This entity is a VIE (See Note 2).[7]The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.[8]The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 5.837% indirect ownership in the joint venture, and (3) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture. The Company’s partners will fund required capital until their aggregate investment is approximately 58% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.[9]The Company’s partner will fund required capital until its aggregate investment is approximately 80% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests.

Investments in Unconsolidated_4

Investments in Unconsolidated Joint Ventures (Balance Sheets of the Unconsolidated Joint Ventures) (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
ASSETS
Total real estate		$ 19,539,375	$ 19,496,442
Total assets		24,625,422	24,207,669
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Mortgage and notes payable, net		3,273,553	3,272,368
Other Liabilities		465,276	450,918
Members’/Partners’ equity		6,062,787	6,132,919
Total liabilities and equity / capital		24,625,422	24,207,669
Carying value of the Company's investment in unconsolidated joint ventures		1,752,617	1,715,911
Right-of-use assets - finance leases		237,503	237,510
Right of use assets - operating leases		166,699	167,351
Lease liabilities - finance leases		250,567	249,335
Lease liabilities - operating leases		204,435	204,686
Unconsolidated Joint Ventures [Member]
ASSETS
Total real estate	[1]	6,649,580	6,537,554
Other assets		755,055	756,786
Total assets		7,404,635	7,294,340
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Mortgage and notes payable, net		4,037,789	4,022,746
Other Liabilities	[2]	723,660	716,271
Members’/Partners’ equity		2,643,186	2,555,323
Total liabilities and equity / capital		7,404,635	7,294,340
Company's share of equity		1,271,419	1,238,929
Basis differentials	[3]	399,705	391,556
Carying value of the Company's investment in unconsolidated joint ventures	[4]	1,671,124	1,630,485
Right-of-use assets - finance leases		248,900	248,900
Right of use assets - operating leases		20,900	21,200
Lease liabilities - finance leases		381,000	382,200
Lease liabilities - operating leases		30,500	30,500
Unconsolidated Joint Ventures [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Other Liabilities		81,500	85,400
Colorado Center
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials		301,097	301,820
Carying value of the Company's investment in unconsolidated joint ventures	[5]	234,635	233,862
Gateway Commons Complex [Member]
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials		47,707	47,808
Carying value of the Company's investment in unconsolidated joint ventures	[5]	337,535	324,038
Dock 72
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Other Liabilities	[5]	(15,362)	(19,921)
Basis differentials		(98,120)	(98,980)
200 Fifth Avenue JV LLC
LIABILITIES AND MEMBERS'/PARTNERS' EQUITY
Basis differentials		99,381	94,497
Carying value of the Company's investment in unconsolidated joint ventures	[5]	$ 114,919	$ 120,083
[1]At March 31, 2023 and December 31, 2022, this amount included right of use assets - finance leases totaling approximately $248.9 million. At March 31, 2023 and December 31, 2022, this amount included right of use assets - operating leases totaling approximately $20.9 million and $21.2 million, respectively.[2]At March 31, 2023 and December 31, 2022, this amount included lease liabilities - finance leases totaling approximately $381.0 million and $382.2 million, respectively. At March 31, 2023 and December 31, 2022, this amount included lease liabilities - operating leases totaling approximately $30.5 million.[3]This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The majority of the Company’s basis differences are as follows: March 31, 2023 December 31, 2022 Property (in thousands) Colorado Center $ 301,097 $ 301,820 200 Fifth Avenue 99,381 94,497 Gateway Commons 47,707 47,808 Dock 72 (98,120) (98,980) These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

Investments in Unconsolidated_5

Investments in Unconsolidated Joint Ventures (Statements of Operations of the Joint Ventures) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Schedule of Equity Method Investments [Line Items]
Total revenue		$ 803,200	$ 754,307
Expenses
Transaction costs		911	0
Depreciation and amortization		208,734	177,624
Total expenses		568,661	499,978
Other income (expense)
Interest expense		(134,207)	(101,228)
Gains on sales of real estate		0	22,701
Net income		105,628	176,957
Income (Loss) from Equity Method Investments		(7,569)	2,189
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Total revenue	[1]	151,423	124,491
Expenses
Operating		57,206	45,641
Transaction costs		74	0
Depreciation and amortization		49,978	44,664
Total expenses		107,258	90,305
Other income (expense)
Losses from early extinguishment of debt		0	(1,327)
Interest expense		(57,250)	(30,373)
Unrealized loss on derivative instruments		(10,610)	0
Net income		(23,695)	2,486
Company's share of net income		(6,902)	3,394
Basis differential	[2]	(667)	(1,205)
Income (Loss) from Equity Method Investments		(7,569)	2,189
Straight Line Rent Adjustments		6,300	27,500
Above and below market rent adjustments, net		200	100
Colorado Center [Member] | Unconsolidated Joint Ventures [Member]
Other income (expense)
Straight Line Rent Adjustments		$ 300	$ 100
[1]Includes straight-line rent adjustments of approximately $6.3 million and $27.5 million for the three months ended March 31, 2023 and 2022, respectively.[2]Includes straight-line rent adjustments of approximately $0.3 million and $0.1 million for the three months ended March 31, 2023 and 2022, respectively. Also includes net above-/below-market rent adjustments of approximately $0.2 million and $0.1 million for the three months ended March 31, 2023 and 2022, respectively.

Investment in Unconsolidated Jo

Investment in Unconsolidated Joint Ventures (Narrative) (Details) - Worldgate Drive - Unconsolidated Properties $ in Thousands	Jan. 31, 2023 USD ($) ft² a Vehicles Building
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50%
Payments to Acquire Interest in Joint Venture | $	$ 17,000
Net Rentable Area (in sf) | ft²	350,000
Number of buildings | Building	2
Number of parking space | Vehicles	1,200
Area of Land | a	10

Unsecured Term Loan (Details)

Unsecured Term Loan (Details) $ in Thousands	Mar. 31, 2023 USD ($)	Jan. 04, 2023 USD ($) mo Rate	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Unsecured term loan | $	$ 1,194,916		$ 730,000
2022 Unsecured Term Loan
Debt Instrument [Line Items]
Repayments of Unsecured Debt | $		$ 730,000
Payment for Debt Extinguishment or Debt Prepayment Cost | $		0
2023 Unsecured Term Loan
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | $		$ 1,200,000
Unsecured term loan | $	$ 1,200,000
Debt Instrument, Basis Spread on Variable Rate | Rate		1%
Line of Credit, Additional Borrowing Capacity | $		$ 300,000
Number of extensions		1
Extension Option (in months) | mo		12
Proceeds from Unsecured Lines of Credit | $		$ 1,200,000
2023 Unsecured Term Loan | Minimum [Member]
Debt Instrument [Line Items]
Number of Additional Term Loans		1
2023 Unsecured Term Loan | Fed Funds Effective Rate Overnight Index Swap Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate		0.50%
2023 Unsecured Term Loan | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate		1%
2023 Unsecured Term Loan | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0%
2023 Unsecured Term Loan | Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate		0.60%
2023 Unsecured Term Loan | Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate		0%
2023 Unsecured Term Loan | Adjusted Term Secured Overnight Financing Rate (Adjusted Term SOFR)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.85%	0.85%
2023 Unsecured Term Loan | Adjusted Term Secured Overnight Financing Rate (Adjusted Term SOFR) | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate		1.60%
2023 Unsecured Term Loan | Adjusted Term Secured Overnight Financing Rate (Adjusted Term SOFR) | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate		0.75%

Commitments And Contingencies (

Commitments And Contingencies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) ft² Real_Estate_Properties
Commitments And Contingencies [Line Items]
Letter of credit and performance obligations	$ 25,700
Property insurance program per occurrence limits	1,000,000
Per occurrence limit for NBCR Coverage	1,000,000
Value of program trigger	$ 200,000
Coinsurance of program trigger	20%
Program trigger deductible	20%
Per occurrence limit of the earthquake insurance which covers San Francisco and Los Angeles regions	$ 330,000
Annual aggregate limit of the earthquake insurance which covers San Francisco and Los Angeles regions	330,000
Amount of earthquake insurance provided by IXP, LLC as direct insurer San Francisco and Los Angeles	$ 30,000
Deductible in insurance as a percentage of the value of the affected property, San Francisco and Los Angeles	5%
Per Occurrence Limit of Earthquake Insurance Seattle	$ 110,000
Annual Aggregate Limit of Earthquake Insurance Seattle	$ 110,000
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle	2%
Boston Properties Limited Partnership
Commitments And Contingencies [Line Items]
Operating partnership guarantee to cover liabilities of IXP	$ 20,000
767 Venture, LLC [Member]
Commitments And Contingencies [Line Items]
Maximum funding obligation	12,500
Property insurance program per occurrence limits	1,625,000
601 Lexington Avenue
Commitments And Contingencies [Line Items]
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP	1,350,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism	750,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism	600,000
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism	$ 1,750,000
Residential Properties [Member] | Scenario, Plan
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²	400,000
Office and Life Sciences Building [Member]
Commitments And Contingencies [Line Items]
Number of real estate properties | Real_Estate_Properties	171
Office and Life Sciences Building [Member] | Scenario, Plan
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²	1,100,000
Number of real estate properties	2

Noncontrolling Interests (Narra

Noncontrolling Interests (Narrative) (Details) - Boston Properties Limited Partnership	Mar. 31, 2023 shares
OP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	16,527,638
LTIP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	2,131,785
2012 OPP and 2013-2020 MYLTIP [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	514,854
MYLTIP 2021
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	350,989
MYLTIP 2022
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	253,453
MYLTIP 2023
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding	322,053

(Common Units) (Narrative) (Det

(Common Units) (Narrative) (Details) $ / shares in Units, $ in Thousands			3 Months Ended
	Feb. 07, 2023 USD ($)	Feb. 03, 2023 USD ($) shares	Mar. 31, 2023 USD ($) yr $ / shares shares	Dec. 31, 2022 USD ($)
Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount | $			$ 1,074,648	$ 1,280,886
MYLTIP | Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Vesting Period			3 years
Unvested MYLTIP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
unvested MYLTIP distributions as compared to total distributions (percentage)			10%
MYLTIP 2021 | Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding			350,989
MYLTIP 2020 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Final awards percentage of target		50%
Value of MYLTIP Awards | $		$ 3,800
Forfeitures, in units		152,460
MYLTIP 2022 | Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding			253,453
MYLTIP 2023
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Vesting Period	3 years
Value of MYLTIP Awards | $	$ 13,100
MYLTIP 2023 | Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling Interest, Outstanding			322,053
OP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares)			5,188
Restriction on redemption of OP Unit to Common Stock (in years) | yr			1
Redemption of OP Unit equivalent to Common Stock (in shares)			1
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount | $			$ 1,100,000
Closing price of common stock (in dollars per share) | $ / shares			$ 54.12
Vested 2012 OPP units and MYLTIPS
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares)			5,188

Noncontrolling Interests Common

Noncontrolling Interests Common Units Distributions (Details) - $ / shares	Jan. 30, 2023	Apr. 29, 2022	Jan. 28, 2022	Mar. 20, 2023
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit				$ 0.98
Dividends, Per Unit, Cash Paid	$ 0.98	$ 0.98	$ 0.98
Boston Properties Limited Partnership
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit				0.98
Dividends, Per Unit, Cash Paid	0.98	0.98	0.98
Boston Properties Limited Partnership | Op units and LTIP units
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit				0.98
Dividends, Per Unit, Cash Paid	0.98	0.98	0.98
Boston Properties Limited Partnership | Unvested MYLTIP Units [Member]
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit				$ 0.098
Dividends, Per Unit, Cash Paid	$ 0.098	$ 0.098	$ 0.098

Noncontrolling Interests (Prope

Noncontrolling Interests (Property Partnerships) (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Noncontrolling Interest [Line Items]
Noncontrolling Interest in Limited Partnerships	$ 1,552,070	$ 1,547,317

Stockholders' Equity _ Partne_3

Stockholders' Equity / Partners' Capital Narrative (Details) $ in Millions			3 Months Ended
	Feb. 01, 2023 shares	May 22, 2020 USD ($) yr	Mar. 31, 2023 shares	Dec. 31, 2022 shares	Jun. 02, 2017 USD ($)
Class of Stock [Line Items]
Common Stock, Shares, Outstanding			156,829,793	156,757,867
General Partners' Capital Account, Units Outstanding (in units)			1,754,892
Limited Partners' Capital Account, Units Outstanding (in units)			155,074,901
Options exercised			0
Shares of Common Stock issued in connection with redemption of an equal number of OP Units (in shares)			5,188
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period	49,359
ATM Program [Member]
Class of Stock [Line Items]
At The Market Stock Offering Program Aggregate Value Of Common Stock | $		$ 600			$ 600
At Market Stock Offering Program Maximum Length Of Sale (in years) | yr		3

Stockholders' Equity _ Partne_4

Stockholders' Equity / Partners' Capital Dividends / Distributions (Details) - $ / shares	Jan. 30, 2023	Apr. 29, 2022	Jan. 28, 2022	Mar. 20, 2023
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit				$ 0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	$ 0.98	$ 0.98	$ 0.98
Boston Properties Limited Partnership
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit				0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	0.98	0.98	0.98
Boston Properties Limited Partnership | Op units and LTIP units
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit				0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	0.98	0.98	0.98
Boston Properties Limited Partnership | Unvested MYLTIP Units [Member]
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit				$ 0.098
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	$ 0.098	$ 0.098	$ 0.098

Segment Information (Schedule O

Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the company's common shareholders / unitholders	$ 77,890	$ 143,047
Noncontrolling interest-common units of the Operating Partnership	(9,078)	(16,361)
Noncontrolling interest in property partnerships	(18,660)	(17,549)
Interest expense	(134,207)	(101,228)
Company's share of net operating income from joint ventures	(491,006)	(469,316)
Depreciation and amortization expense	(208,734)	(177,624)
Transaction costs	(911)	0
General and administrative expense	(55,802)	(43,194)
Unrealized Gain (Loss) on Investments	(259)	0
Gains (losses) from investments in securities	(1,665)	2,262
Interest and other income (loss)	(10,941)	(1,228)
Gains on sales of real estate	0	(22,701)
Income (loss) from unconsolidated joint ventures	7,569	(2,189)
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the company's common shareholders / unitholders	77,890	143,047
Noncontrolling interest-common units of the Operating Partnership	9,078	16,361
Noncontrolling interest in property partnerships	18,660	17,549
Interest expense	134,207	101,228
Depreciation and amortization expense	208,734	177,624
Transaction costs	911	0
Operating expense	5,235	4,065
General and administrative expense	55,802	43,194
Gains (losses) from investments in securities	1,665	(2,262)
Interest and other income (loss)	10,941	1,228
Gains on sales of real estate	0	22,701
Income (loss) from unconsolidated joint ventures	(7,569)	2,189
Other revenue	5,235	4,065
Company's share of Net Operating Income	484,665	459,582
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(57,250)	(30,373)
Losses from early extinguishment of debt	0	1,327
Depreciation and amortization expense	(49,978)	(44,664)
Transaction costs	(74)	0
Income (loss) from unconsolidated joint ventures	7,569	(2,189)
Unconsolidated Joint Ventures [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	40,756	37,321
Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the company's common shareholders / unitholders	88,830	161,829
Noncontrolling interest in property partnerships	(18,660)	(17,549)
Interest expense	(134,207)	(101,228)
Depreciation and amortization expense	(206,872)	(175,886)
Transaction costs	(911)	0
General and administrative expense	(55,802)	(43,194)
Unrealized Gain (Loss) on Investments	(259)	0
Gains (losses) from investments in securities	(1,665)	2,262
Interest and other income (loss)	(10,941)	(1,228)
Gains on sales of real estate	0	(23,384)
Income (loss) from unconsolidated joint ventures	7,569	(2,189)
Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the company's common shareholders / unitholders	88,830	161,829
Noncontrolling interest in property partnerships	18,660	17,549
Interest expense	134,207	101,228
Depreciation and amortization expense	206,872	175,886
Transaction costs	911	0
Operating expense	5,235	4,065
General and administrative expense	55,802	43,194
Gains (losses) from investments in securities	1,665	(2,262)
Interest and other income (loss)	10,941	1,228
Gains on sales of real estate	0	23,384
Other revenue	5,235	4,065
Company's share of Net Operating Income	484,665	459,582
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(8,980)	(5,831)
Management Service [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	8,980	5,831
Management Service [Member] | Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(8,980)	(5,831)
Management Service [Member] | Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	8,980	5,831
Noncontrolling interest - property partnerships [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	47,097	47,055
Noncontrolling interest - property partnerships [Member] | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	47,097	47,055
Unrealized Gain (Loss) on Investments	259	0
Noncontrolling interest - property partnerships [Member] | Boston Properties Limited Partnership | Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	47,097	47,055
Unrealized Gain (Loss) on Investments	259	0
Income (loss) from unconsolidated joint ventures	$ (7,569)	$ 2,189

Segment Information (Schedule_2

Segment Information (Schedule Of Segment Reporting By Geographic Area And Property Type) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023		Mar. 31, 2022
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office	[1]	$ 769,158		$ 726,888
Rental Revenue: Residential	[1]	11,726		12,966
Rental Revenue Total	[1]	$ 788,985		$ 744,411
Rental Revenue: % of Grand Totals		100%		100%
Rental Expenses: Class A Office		$ 285,845		$ 263,823
Rental Expenses: Residential		5,463		6,432
Rental Expenses: Total		$ 297,979		$ 275,095
Rental Expenses: % Of Grand Totals		100%		100%
Net Operating Income		$ 491,006		$ 469,316
Net Operating Income: % of Grand Totals		100%		100%
Company's Share of Net Operating Income: % of Grand Totals		100%		100%
Boston [Member]
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office	[1]	$ 269,951		$ 242,078
Rental Revenue: Residential	[1]	4,049		3,596
Rental Revenue Total	[1]	$ 282,101		$ 250,231
Rental Revenue: % of Grand Totals		35.76%		33.61%
Rental Expenses: Class A Office		$ 100,049		$ 90,528
Rental Expenses: Residential		1,552		1,437
Rental Expenses: Total		$ 108,272		$ 96,805
Rental Expenses: % Of Grand Totals		36.34%		35.19%
Net Operating Income		$ 173,829		$ 153,426
Net Operating Income: % of Grand Totals		35.41%		32.69%
Company's Share of Net Operating Income: % of Grand Totals		35.41%		32.94%
Los Angeles [Member]
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office	[1]	$ 0		$ 0
Rental Revenue: Residential	[1]	0		0
Rental Revenue Total	[1]	$ 0		$ 0
Rental Revenue: % of Grand Totals		0%		0%
Rental Expenses: Class A Office		$ 0		$ 0
Rental Expenses: Residential		0		0
Rental Expenses: Total		$ 0		$ 0
Rental Expenses: % Of Grand Totals		0%		0%
Net Operating Income		$ 0		$ 0
Net Operating Income: % of Grand Totals		0%		0%
Company's Share of Net Operating Income: % of Grand Totals		2.73%		2.99%
New York [Member]
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office	[1]	$ 258,192		$ 256,870
Rental Revenue: Residential	[1]	0		0
Rental Revenue Total	[1]	$ 258,192		$ 256,870
Rental Revenue: % of Grand Totals		32.72%		34.51%
Rental Expenses: Class A Office		$ 102,485		$ 96,340
Rental Expenses: Residential		0		0
Rental Expenses: Total		$ 102,485		$ 96,340
Rental Expenses: % Of Grand Totals		34.39%		35.02%
Net Operating Income		$ 155,707		$ 160,530
Net Operating Income: % of Grand Totals		31.71%		34.21%
Company's Share of Net Operating Income: % of Grand Totals		25.39%		27.21%
San Francisco [Member]
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office	[1]	$ 136,093		$ 132,375
Rental Revenue: Residential	[1]	3,642		2,391
Rental Revenue Total	[1]	$ 139,735		$ 134,766
Rental Revenue: % of Grand Totals		17.71%		18.10%
Rental Expenses: Class A Office		$ 46,085		$ 43,408
Rental Expenses: Residential		2,173		1,868
Rental Expenses: Total		$ 48,258		$ 45,276
Rental Expenses: % Of Grand Totals		16.20%		16.46%
Net Operating Income		$ 91,477		$ 89,490
Net Operating Income: % of Grand Totals		18.63%		19.07%
Company's Share of Net Operating Income: % of Grand Totals		19.59%		20.16%
Seattle
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office		$ 14,258	[1]	$ 0
Rental Revenue: Residential		0	[1]	0
Rental Revenue Total		$ 14,258	[1]	$ 0
Rental Revenue: % of Grand Totals		1.81%		0%
Rental Expenses: Class A Office		$ 2,960		$ 0
Rental Expenses: Residential		0		0
Rental Expenses: Total		$ 2,960		$ 0
Rental Expenses: % Of Grand Totals		0.99%		0%
Net Operating Income		$ 11,298		$ 0
Net Operating Income: % of Grand Totals		2.30%		0%
Company's Share of Net Operating Income: % of Grand Totals		2.71%		0.43%
Washington, DC [Member]
Segment Reporting Information [Line Items]
Rental Revenue: Class A Office	[1]	$ 90,664		$ 95,565
Rental Revenue: Residential	[1]	4,035		6,979
Rental Revenue Total	[1]	$ 94,699		$ 102,544
Rental Revenue: % of Grand Totals		12%		13.78%
Rental Expenses: Class A Office		$ 34,266		$ 33,547
Rental Expenses: Residential		1,738		3,127
Rental Expenses: Total		$ 36,004		$ 36,674
Rental Expenses: % Of Grand Totals		12.08%		13.33%
Net Operating Income		$ 58,695		$ 65,870
Net Operating Income: % of Grand Totals		11.95%		14.03%
Company's Share of Net Operating Income: % of Grand Totals		14.17%		16.27%
Hotel [Member]
Segment Reporting Information [Line Items]
Other revenue	[1]	$ 8,101		$ 4,557
Operating expense		6,671		4,840
Hotel [Member] | Boston [Member]
Segment Reporting Information [Line Items]
Other revenue	[1]	8,101		4,557
Operating expense		6,671		4,840
Hotel [Member] | Los Angeles [Member]
Segment Reporting Information [Line Items]
Other revenue	[1]	0		0
Operating expense		0		0
Hotel [Member] | New York [Member]
Segment Reporting Information [Line Items]
Other revenue	[1]	0		0
Operating expense		0		0
Hotel [Member] | San Francisco [Member]
Segment Reporting Information [Line Items]
Other revenue	[1]	0		0
Operating expense		0		0
Hotel [Member] | Seattle
Segment Reporting Information [Line Items]
Other revenue		0	[1]	0
Operating expense		0		0
Hotel [Member] | Washington, DC [Member]
Segment Reporting Information [Line Items]
Other revenue	[1]	0		0
Operating expense		0		0
Noncontrolling interest - property partnerships [Member]
Segment Reporting Information [Line Items]
Net Operating Income		(47,097)		(47,055)
Noncontrolling interest - property partnerships [Member] | Boston [Member]
Segment Reporting Information [Line Items]
Net Operating Income		(10,817)		(11,735)
Noncontrolling interest - property partnerships [Member] | Los Angeles [Member]
Segment Reporting Information [Line Items]
Net Operating Income		0		0
Noncontrolling interest - property partnerships [Member] | New York [Member]
Segment Reporting Information [Line Items]
Net Operating Income		(36,280)		(35,320)
Noncontrolling interest - property partnerships [Member] | San Francisco [Member]
Segment Reporting Information [Line Items]
Net Operating Income		0		0
Noncontrolling interest - property partnerships [Member] | Seattle
Segment Reporting Information [Line Items]
Net Operating Income		0		0
Noncontrolling interest - property partnerships [Member] | Washington, DC [Member]
Segment Reporting Information [Line Items]
Net Operating Income		0		0
Unconsolidated Joint Ventures [Member] | Boston [Member]
Segment Reporting Information [Line Items]
Net Operating Income		8,577		9,693
Unconsolidated Joint Ventures [Member] | Los Angeles [Member]
Segment Reporting Information [Line Items]
Net Operating Income		13,225		13,757
Unconsolidated Joint Ventures [Member] | New York [Member]
Segment Reporting Information [Line Items]
Net Operating Income		3,650		(156)
Unconsolidated Joint Ventures [Member] | San Francisco [Member]
Segment Reporting Information [Line Items]
Net Operating Income		3,464		3,181
Unconsolidated Joint Ventures [Member] | Seattle
Segment Reporting Information [Line Items]
Net Operating Income		1,846		1,955
Unconsolidated Joint Ventures [Member] | Washington, DC [Member]
Segment Reporting Information [Line Items]
Net Operating Income		9,994		8,891
Company's Share [Member]
Segment Reporting Information [Line Items]
Net Operating Income		484,665		459,582
Company's Share [Member] | Boston [Member]
Segment Reporting Information [Line Items]
Net Operating Income		171,589		151,384
Company's Share [Member] | Los Angeles [Member]
Segment Reporting Information [Line Items]
Net Operating Income		13,225		13,757
Company's Share [Member] | New York [Member]
Segment Reporting Information [Line Items]
Net Operating Income		123,077		125,054
Company's Share [Member] | San Francisco [Member]
Segment Reporting Information [Line Items]
Net Operating Income		94,941		92,671
Company's Share [Member] | Seattle
Segment Reporting Information [Line Items]
Net Operating Income		13,144		1,955
Company's Share [Member] | Washington, DC [Member]
Segment Reporting Information [Line Items]
Net Operating Income		$ 68,689		$ 74,761
[1]Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Earnings Per Share _ Common U_3

Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 77,890	$ 143,047
Net income attributable to the company's common shareholders / unitholders (in shares / units)	156,803,000	156,650,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)	$ 0.50	$ 0.91
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)	$ 0.50	$ 0.91
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0
Stock Based Compensation (in shares / units)	240,000	354,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ 0	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders	$ 77,890	$ 143,047
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)	157,043,000	157,004,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.50	$ 0.91
Boston Properties Limited Partnership
Redeemable Common Units	17,849,000	17,626,000
Basic Earnings:
Net income attributable to the company's common shareholders / unitholders	$ 88,830	$ 161,829
Net income attributable to the company's common shareholders / unitholders (in shares / units)	174,652,000	174,276,000
Net income attributable to the company's common shareholders / unitholders (in dollars per share / unit)	$ 0.51	$ 0.93
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)	$ 0.51	$ 0.93
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0
Stock Based Compensation (in shares / units)	240,000	354,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ 0	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders	$ 88,830	$ 161,829
Diluted Earnings: Net income attributable to the Company's common shareholders / unitholders (in shares / units)	174,892,000	174,630,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.51	$ 0.93

Stock Option and Incentive Pl_2

Stock Option and Incentive Plan (Narrative) (Details) - USD ($) $ in Thousands	Feb. 07, 2023	Feb. 03, 2023
MYLTIP 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of MYLTIP Awards		$ 3,800
Final awards percentage of target		50%
Forfeitures, in units		152,460
MYLTIP 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	The 2023 MYLTIP awards consist of two, equally weighted (50% each) components that utilize BXP’s TSR over a three-year measurement period as the performance metric.
Distributions percent before measurement date	10%
Vesting Period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	Earned awards (if any) will vest 100% on February 6, 2026, but, in general, may not be converted, redeemed, sold or otherwise transferred for one additional year thereafter.
Value of MYLTIP Awards	$ 13,100
Minimum [Member] | MYLTIP 2023 | Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	0
Maximum [Member] | MYLTIP 2023 | Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	322,053
Target | MYLTIP 2023 | Boston Properties Limited Partnership
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance	161,026

Stock Option and Incentive Pl_3

Stock Option and Incentive Plan Stock and Units (Narrative) (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued | shares	156,908,693		156,836,767
Stock based compensation expense	$ 25,900	$ 20,900
Common Stock, Value, Issued	$ 1,568		$ 1,568
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued | shares	66,634
LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value Of LTIP Units Issued	$ 28,100
Unvested Restricted stock and LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Annual Installments for Vesting	4
Boston Properties Limited Partnership | LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP units issued (in shares) | shares	403,446
Boston Properties Limited Partnership | MYLTIP 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued | shares	322,053
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee and director payment per share (in dollars per share) | $ / shares	$ 0.01
Common Stock, Value, Issued	$ 5,000
LTIP and MYLTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee and director payment per share (in dollars per share) | $ / shares	$ 0.25
Ltips (including vested MYLTIPS) And Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 36,000
Unvested MYLTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 9,100
Weighted-average period (years)	2 years 4 months 24 days

Subsequent Events (Details)

Subsequent Events (Details) $ in Thousands	Jun. 01, 2023	May 02, 2023 USD ($)	Apr. 21, 2023 USD ($) ft² Year	Jan. 04, 2023 Rate	Apr. 29, 2023 ft²
2023 Unsecured Term Loan
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate				1%
Interest Rate Swap
Subsequent Event [Line Items]
Derivative, Inception Date		May 02, 2023
Derivative, Notional Amount | $		$ 1,200,000
Derivative, Average Fixed Interest Rate		4.642%
Derivative, Maturity Date		May 16, 2024
Subsequent Event [Member] | 2023 Unsecured Term Loan
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.592%
Subsequent Event [Member] | 2100 Pennsylvania Avenue
Subsequent Event [Line Items]
Area of Real Estate Property | ft²					480,000
Subsequent Event [Member] | Unconsolidated Joint Ventures [Member] | 7750 Wisconsin Avenue [Member]
Subsequent Event [Line Items]
Ownership Percentage			50%
Area of Real Estate Property | ft²			734,000
Leased percentage			100%
Debt Instrument, Description of Variable Rate Basis	Term SOFR
Debt Instrument, Basis Spread on Variable Rate	1.35%
Extension Option (in years) | Year			1
Subsequent Event [Member] | Unconsolidated Joint Ventures [Member] | 7750 Wisconsin Avenue [Member] | Extended Maturity
Subsequent Event [Line Items]
Debt Instrument, Term			1 year
Construction Loan | $			$ 252,600