Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Net income	$ 444,200	$ 269,397
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	360,770	360,403
Amortization of right of use assets - operating leases	1,407	2,963
Non-cash compensation expense	36,195	34,370
Loss (income) from unconsolidated joint ventures	(2,135)	(3,852)
Distributions of net cash flow from operations of unconsolidated joint ventures	10,097	14,387
Losses (gains) from investments in securities	6,978	(3,934)
Allowance for current expected credit losses	(458)	(418)
Non-cash portion of interest expense	12,528	11,784
Settlement of accreted debt discount on redemption of unsecured senior notes	0	(6,290)
Loss from early extinguishment of debt	0	898
Other Income - assignment fee	(6,624)	0
Gains on sales of real estate	(118,948)	(7,756)
Change in assets and liabilities:
Tenant and other receivables, net	10,167	17,110
Notes receivable, net	(152)	(277)
Accrued rental income, net	(48,901)	(39,434)
Prepaid expenses and other assets	6,326	(14,122)
Operating Lease, Payments	82	(1,566)
Accounts payable and accrued expenses	(18,636)	6,100
Accrued interest payable	2,036	1,741
Other liabilities	(37,732)	(53,919)
Tenant leasing costs	(40,561)	(27,109)
Total adjustments	172,439	291,079
Net cash provided by operating activities	616,639	560,476
Cash flows from investing activities:
Acquisitions of real estate	(727,835)	(100,176)
Construction in progress	(237,182)	(235,577)
Building and other capital improvements	(63,278)	(66,033)
Tenant improvements	(97,844)	(161,619)
Proceeds from sales of real estate	157,345	0
Proceeds from assignment fee	6,624	0
Capital contributions to unconsolidated joint ventures	(69,819)	(20,032)
Capital distributions from unconsolidated joint ventures	36,622	122
Proceeds from note receivable	10,000	0
Proceeds from sale of investment in unconsolidated joint venture	0	17,789
Investments in securities, net	5,197	1,915
Net cash used in investing activities	(980,170)	(563,611)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(9,294)
Proceeds from unsecured senior notes	0	846,345
Redemption of unsecured senior notes	0	(843,710)
Borrowings on unsecured line of credit	340,000	0
Repayments of unsecured line of credit	(320,000)	0
Borrowings on unsecured term loan	730,000	0
Repayments of unsecured term loan	0	(500,000)
Redemption of preferred stock	0	(200,000)
Payments on finance lease obligations	0	618
Deferred financing costs	(2,230)	(13,642)
Debt prepayment and extinguishment costs	0	(185)
Net activity from equity transactions	(366)	19,580
Dividends and distributions	(341,951)	(343,117)
Contributions from noncontrolling interests in property partnerships	849	2,420
Distributions to noncontrolling interests in property partnerships	(41,079)	(37,929)
Net cash provided by (used in) financing activities	365,223	(1,078,914)
Net increase (decrease) in cash and cash equivalents and cash held in escrows	1,692	(1,082,049)
Cash and cash equivalents and cash held in escrows, beginning of period	501,158	1,719,329
Cash and cash equivalents and cash held in escrows, end of period	502,850	637,280
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	452,692	1,668,742
Cash held in escrows, beginning of period	48,466	50,587
Cash and cash equivalents, end of period	456,491	557,307
Cash held in escrows,end of period	46,359	79,973
Supplemental disclosures:
Cash paid for interest	216,409	226,367
Interest capitalized	27,819	25,046
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(65,435)	(98,672)
Change in real estate included in accounts payable and accrued expenses	40,655	(22,822)
Right-of-use assets obtained in exchange for operating lease liabilities	0	26,887
Construction in progress, net deconsolidated	(11,316)	0
Transfer to Investments	11,316	0
Dividends and distributions declared but not paid	170,937	169,718
Conversions of noncontrolling interests to stockholders’ equity	5,429	6,285
Issuance of restricted securities to employees and non-employee directors	47,198	42,515
Boston Properties Limited Partnership
Net income	451,712	274,222
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	357,302	355,578
Amortization of right of use assets - operating leases	1,407	2,963
Non-cash compensation expense	36,195	34,370
Loss (income) from unconsolidated joint ventures	(2,135)	(3,852)
Distributions of net cash flow from operations of unconsolidated joint ventures	10,097	14,387
Losses (gains) from investments in securities	6,978	(3,934)
Allowance for current expected credit losses	(458)	(418)
Non-cash portion of interest expense	12,528	11,784
Settlement of accreted debt discount on redemption of unsecured senior notes	0	(6,290)
Loss from early extinguishment of debt	0	898
Other Income - assignment fee	(6,624)	0
Gains on sales of real estate	(122,992)	(7,756)
Change in assets and liabilities:
Tenant and other receivables, net	10,167	17,110
Notes receivable, net	(152)	(277)
Accrued rental income, net	(48,901)	(39,434)
Prepaid expenses and other assets	6,326	(14,122)
Operating Lease, Payments	82	(1,566)
Accounts payable and accrued expenses	(18,636)	6,100
Accrued interest payable	2,036	1,741
Other liabilities	(37,732)	(53,919)
Tenant leasing costs	(40,561)	(27,109)
Total adjustments	164,927	286,254
Net cash provided by operating activities	616,639	560,476
Cash flows from investing activities:
Acquisitions of real estate	(727,835)	(100,176)
Construction in progress	(237,182)	(235,577)
Building and other capital improvements	(63,278)	(66,033)
Tenant improvements	(97,844)	(161,619)
Proceeds from sales of real estate	157,345	0
Proceeds from assignment fee	6,624	0
Capital contributions to unconsolidated joint ventures	(69,819)	(20,032)
Capital distributions from unconsolidated joint ventures	36,622	122
Proceeds from note receivable	10,000	0
Proceeds from sale of investment in unconsolidated joint venture	0	17,789
Investments in securities, net	5,197	1,915
Net cash used in investing activities	(980,170)	(563,611)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(9,294)
Proceeds from unsecured senior notes	0	846,345
Redemption of unsecured senior notes	0	(843,710)
Borrowings on unsecured line of credit	340,000	0
Repayments of unsecured line of credit	(320,000)	0
Borrowings on unsecured term loan	730,000	0
Repayments of unsecured term loan	0	(500,000)
Redemption of preferred stock	0	(200,000)
Payments on finance lease obligations	0	618
Deferred financing costs	(2,230)	(13,642)
Debt prepayment and extinguishment costs	0	(185)
Net activity from equity transactions	(366)	19,580
Dividends and distributions	(341,951)	(343,117)
Contributions from noncontrolling interests in property partnerships	849	2,420
Distributions to noncontrolling interests in property partnerships	(41,079)	(37,929)
Net cash provided by (used in) financing activities	365,223	(1,078,914)
Net increase (decrease) in cash and cash equivalents and cash held in escrows	1,692	(1,082,049)
Cash and cash equivalents and cash held in escrows, beginning of period	501,158	1,719,329
Cash and cash equivalents and cash held in escrows, end of period	502,850	637,280
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	452,692	1,668,742
Cash held in escrows, beginning of period	48,466	50,587
Cash and cash equivalents, end of period	456,491	557,307
Cash held in escrows,end of period	46,359	79,973
Supplemental disclosures:
Cash paid for interest	216,409	226,367
Interest capitalized	27,819	25,046
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(65,435)	(97,358)
Change in real estate included in accounts payable and accrued expenses	40,655	(22,822)
Lease Obligation Incurred	0	26,887
Construction in progress, net deconsolidated	(11,316)	0
Transfer to Investments	11,316	0
Dividends and distributions declared but not paid	170,937	169,718
Conversions of noncontrolling interests to stockholders’ equity	5,429	6,285
Issuance of restricted securities to employees and non-employee directors	$ 47,198	$ 42,515