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