Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Net income	$ 241,812	$ 444,200
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	411,311	360,770
Amortization of right of use assets - operating leases	929	1,407
Non-cash compensation expense	41,524	36,195
Loss (income) from unconsolidated joint ventures	14,237	(2,135)
Distributions of net cash flow from operations of unconsolidated joint ventures	11,437	10,097
Losses (gains) from investments in securities	(3,236)	6,978
Allowance for current expected credit losses	264	(458)
Non-cash portion of interest expense	14,940	12,528
Other Income - assignment fee	0	(6,624)
Gains on sales of real estate	0	(118,948)
Unrealized gain on non-real estate investment	(383)	0
Change in assets and liabilities:
Tenant and other receivables, net	3,721	10,167
Notes receivable, net	0	(152)
Accrued rental income, net	(42,965)	(48,901)
Prepaid expenses and other assets	(24,758)	6,326
Lease liabilities - operating leases	140	82
Accounts payable and accrued expenses	6,320	(18,636)
Accrued interest payable	7,314	2,036
Other liabilities	(21,773)	(37,732)
Tenant leasing costs	(47,651)	(40,561)
Total adjustments	371,371	172,439
Net cash provided by operating activities	613,183	616,639
Cash flows from investing activities:
Acquisitions of real estate	0	(727,835)
Construction in progress	(235,331)	(237,182)
Building and other capital improvements	(78,344)	(63,278)
Tenant improvements	(135,743)	(97,844)
Proceeds from sales of real estate	0	157,345
Proceeds from assignment fee	0	6,624
Capital contributions to unconsolidated joint ventures	(103,595)	(69,819)
Capital distributions from unconsolidated joint ventures	7,350	36,622
Investment in non-real estate investments	(733)	0
Issuance of related party note receivable	(10,500)	0
Proceeds from note receivable	0	10,000
Investments in securities, net	2,032	5,197
Net cash used in investing activities	(554,864)	(980,170)
Cash flows from financing activities:
Proceeds from unsecured senior notes	747,727	0
Borrowings on unsecured line of credit	0	340,000
Repayments of unsecured line of credit	0	(320,000)
Borrowings on unsecured term loan	1,200,000	730,000
Repayment of unsecured term loan	(730,000)	0
Deferred financing costs	(12,339)	(2,230)
Net activity from equity transactions	(39)	(366)
Dividends and distributions	(343,325)	(341,951)
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	(36,220)	(41,079)
Net cash provided by financing activities	833,359	365,223
Net increase (decrease) in cash and cash equivalents and cash held in escrows	891,678	1,692
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	1,628,490	502,850
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	1,581,575	456,491
Cash held in escrows,end of period	46,915	46,359
Supplemental disclosures:
Cash paid for interest	273,214	216,409
Interest capitalized	21,153	27,819
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(85,878)	(65,435)
Change in real estate included in accounts payable and accrued expenses	25,562	40,655
Construction in progress, net deconsolidated	0	(11,316)
Investment in unconsolidated joint ventures recorded upon deconsolidation	0	11,316
Dividends and distributions declared but not paid	171,465	170,937
Conversions of noncontrolling interests to stockholders’ equity	794	5,429
Issuance of restricted securities to employees and non-employee directors	47,885	47,198
Boston Properties Limited Partnership
Net income	245,356	451,712
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	407,767	357,302
Amortization of right of use assets - operating leases	929	1,407
Non-cash compensation expense	41,524	36,195
Loss (income) from unconsolidated joint ventures	14,237	(2,135)
Distributions of net cash flow from operations of unconsolidated joint ventures	11,437	10,097
Losses (gains) from investments in securities	(3,236)	6,978
Allowance for current expected credit losses	264	(458)
Non-cash portion of interest expense	14,940	12,528
Other Income - assignment fee	0	(6,624)
Gains on sales of real estate	0	(122,992)
Unrealized gain on non-real estate investment	(383)	0
Change in assets and liabilities:
Tenant and other receivables, net	3,721	10,167
Notes receivable, net	0	(152)
Accrued rental income, net	(42,965)	(48,901)
Prepaid expenses and other assets	(24,758)	6,326
Lease liabilities - operating leases	140	82
Accounts payable and accrued expenses	6,320	(18,636)
Accrued interest payable	7,314	2,036
Other liabilities	(21,773)	(37,732)
Tenant leasing costs	(47,651)	(40,561)
Total adjustments	367,827	164,927
Net cash provided by operating activities	613,183	616,639
Cash flows from investing activities:
Acquisitions of real estate	0	(727,835)
Construction in progress	(235,331)	(237,182)
Building and other capital improvements	(78,344)	(63,278)
Tenant improvements	(135,743)	(97,844)
Proceeds from sales of real estate	0	157,345
Proceeds from assignment fee	0	6,624
Capital contributions to unconsolidated joint ventures	(103,595)	(69,819)
Capital distributions from unconsolidated joint ventures	7,350	36,622
Investment in non-real estate investments	(733)	0
Issuance of related party note receivable	(10,500)	0
Proceeds from note receivable	0	10,000
Investments in securities, net	2,032	5,197
Net cash used in investing activities	(554,864)	(980,170)
Cash flows from financing activities:
Proceeds from unsecured senior notes	747,727	0
Borrowings on unsecured line of credit	0	340,000
Repayments of unsecured line of credit	0	(320,000)
Borrowings on unsecured term loan	1,200,000	730,000
Repayment of unsecured term loan	(730,000)	0
Deferred financing costs	(12,339)	(2,230)
Net activity from equity transactions	(39)	(366)
Dividends and distributions	(343,325)	(341,951)
Contributions from noncontrolling interests in property partnerships	7,555	849
Distributions to noncontrolling interests in property partnerships	(36,220)	(41,079)
Net cash provided by financing activities	833,359	365,223
Net increase (decrease) in cash and cash equivalents and cash held in escrows	891,678	1,692
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	1,628,490	502,850
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	1,581,575	456,491
Cash held in escrows,end of period	46,915	46,359
Supplemental disclosures:
Cash paid for interest	273,214	216,409
Interest capitalized	21,153	27,819
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(84,629)	(65,435)
Change in real estate included in accounts payable and accrued expenses	25,562	40,655
Construction in progress, net deconsolidated	0	(11,316)
Investment in unconsolidated joint ventures recorded upon deconsolidation	0	11,316
Dividends and distributions declared but not paid	171,465	170,937
Conversions of noncontrolling interests to stockholders’ equity	794	5,429
Issuance of restricted securities to employees and non-employee directors	$ 47,885	$ 47,198