Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 864,861	$ 408,647
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	551,445	539,815
Amortization of right of use assets - operating leases	1,843	3,208
Non-cash compensation expense	44,208	43,098
Loss from unconsolidated joint ventures	1,389	1,745
Distributions of net cash flow from operations of unconsolidated joint ventures	20,511	18,462
Losses (gains) from investments in securities	8,549	(3,744)
Allowance for current expected credit losses	(476)	(758)
Non-cash portion of interest expense	19,704	17,584
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	(381,293)	(8,104)
Change in assets and liabilities:
Tenant and other receivables, net	4,133	13,738
Notes receivable, net	(152)	(419)
Accrued rental income, net	(76,268)	(74,283)
Prepaid expenses and other assets	(46,104)	(61,019)
Operating Lease, Payments	447	(24,023)
Accounts payable and accrued expenses	3,167	26,097
Accrued interest payable	(2,900)	(18,237)
Other liabilities	(35,490)	(51,938)
Tenant leasing costs	(58,547)	(37,618)
Total adjustments	47,542	378,212
Net cash provided by operating activities	912,403	786,859
Cash flows from investing activities:
Acquisitions of real estate	(1,320,273)	(218,679)
Construction in progress	(384,083)	(381,104)
Building and other capital improvements	(112,755)	(103,840)
Tenant improvements	(139,986)	(218,878)
Proceeds from sales of real estate	695,231	0
Proceeds from assignment fee	6,624	0
Capital contributions to unconsolidated joint ventures	(109,643)	(95,462)
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	5,043	1,684
Net cash used in investing activities	(1,313,220)	(998,368)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(13,261)
Proceeds from unsecured senior notes	0	1,695,996
Redemption of unsecured senior notes	0	(843,710)
Borrowings on unsecured line of credit	885,000	300,000
Repayments of unsecured line of credit	(690,000)	(300,000)
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	1,250
Deferred financing costs	(2,230)	(20,770)
Debt prepayment and extinguishment costs	0	(185)
Net activity from equity transactions	(359)	20,028
Dividends and distributions	(513,486)	(513,381)
Contributions from noncontrolling interests in property partnerships	849	13,738
Distributions to noncontrolling interests in property partnerships	(61,229)	(65,604)
Net cash provided by (used in) financing activities	348,545	(425,899)
Net increase (decrease) in cash and cash equivalents and cash held in escrows	(52,272)	(637,408)
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	448,886	1,081,921
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	375,774	1,002,728
Cash held in escrows,end of period	73,112	79,193
Supplemental disclosures:
Cash paid for interest	339,067	358,015
Interest capitalized	40,048	36,632
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(95,996)	(159,108)
Change in real estate included in accounts payable and accrued expenses	29,290	(22,104)
Construction in progress, net deconsolidated	(11,316)	0
Transfer to Investments	11,316	0
Right-of-use assets obtained in exchange for operating lease liabilities	0	26,887
Dividends and distributions declared but not paid	170,952	169,739
Conversions of noncontrolling interests to stockholders’ equity	6,388	8,033
Issuance of restricted securities to employees and non-employee directors	48,605	44,257
Boston Properties Limited Partnership
Net income	874,091	415,207
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	546,271	533,255
Amortization of right of use assets - operating leases	1,843	3,208
Non-cash compensation expense	44,208	43,098
Loss from unconsolidated joint ventures	1,389	1,745
Distributions of net cash flow from operations of unconsolidated joint ventures	20,511	18,462
Losses (gains) from investments in securities	8,549	(3,744)
Allowance for current expected credit losses	(476)	(758)
Non-cash portion of interest expense	19,704	17,584
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	(385,349)	(8,104)
Change in assets and liabilities:
Tenant and other receivables, net	4,133	13,738
Notes receivable, net	(152)	(419)
Accrued rental income, net	(76,268)	(74,283)
Prepaid expenses and other assets	(46,104)	(61,019)
Operating Lease, Payments	447	(24,023)
Accounts payable and accrued expenses	3,167	26,097
Accrued interest payable	(2,900)	(18,237)
Other liabilities	(35,490)	(51,938)
Tenant leasing costs	(58,547)	(37,618)
Total adjustments	38,312	371,652
Net cash provided by operating activities	912,403	786,859
Cash flows from investing activities:
Acquisitions of real estate	(1,320,273)	(218,679)
Construction in progress	(384,083)	(381,104)
Building and other capital improvements	(112,755)	(103,840)
Tenant improvements	(139,986)	(218,878)
Proceeds from sales of real estate	695,231	0
Proceeds from assignment fee	6,624	0
Capital contributions to unconsolidated joint ventures	(109,643)	(95,462)
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	5,043	1,684
Net cash used in investing activities	(1,313,220)	(998,368)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(13,261)
Proceeds from unsecured senior notes	0	1,695,996
Redemption of unsecured senior notes	0	(843,710)
Borrowings on unsecured line of credit	885,000	300,000
Repayments of unsecured line of credit	(690,000)	(300,000)
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	1,250
Deferred financing costs	(2,230)	(20,770)
Debt prepayment and extinguishment costs	0	(185)
Net activity from equity transactions	(359)	20,028
Dividends and distributions	(513,486)	(513,381)
Contributions from noncontrolling interests in property partnerships	849	13,738
Distributions to noncontrolling interests in property partnerships	(61,229)	(65,604)
Net cash provided by (used in) financing activities	348,545	(425,899)
Net increase (decrease) in cash and cash equivalents and cash held in escrows	(52,272)	(637,408)
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	448,886	1,081,921
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	375,774	1,002,728
Cash held in escrows,end of period	73,112	79,193
Supplemental disclosures:
Cash paid for interest	339,067	358,015
Interest capitalized	40,048	36,632
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(95,996)	(157,794)
Change in real estate included in accounts payable and accrued expenses	29,290	(22,104)
Construction in progress, net deconsolidated	(11,316)	0
Transfer to Investments	11,316	0
Right-of-use assets obtained in exchange for operating lease liabilities	0	26,887
Dividends and distributions declared but not paid	170,952	169,739
Conversions of noncontrolling interests to stockholders’ equity	6,388	8,033
Issuance of restricted securities to employees and non-employee directors	$ 48,605	$ 44,257