Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net income	$ 569,977	$ 799,918	$ 526,057
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	694,403	639,542	628,573
Impairment loss	1,783	0	0
Non-cash compensation expense	32,911	29,183	28,099
Income from unconsolidated joint ventures	(8,074)	(22,770)	(12,769)
Gain on sale of investment in unconsolidated joint venture	(59,370)	0	0
Distributions of net cash flow from operations of unconsolidated joint ventures	24,955	8,469	7,372
Losses (gains) on investments in securities	(2,273)	653	(1,038)
Non-cash portion of interest expense	(35,052)	(42,271)	(39,343)
Settlement of accreted debt discount on repurchases/repayments of unsecured senior notes and unsecured exchangeable senior notes	0	0	(94,963)
Losses from early extinguishments of debt	371	21,837	0
Gains on sales of real estate	(80,606)	(375,895)	(168,039)
Change in assets and liabilities:
Cash held in escrows	2,277	(18,284)	3,433
Tenant and other receivables, net	3,688	(46,326)	12,869
Accrued rental income, net	(28,127)	(73,911)	(57,899)
Prepaid expenses and other assets	52,923	(16,877)	20,238
Accounts payable and accrued expenses	15,666	(6,310)	3,903
Accrued interest payable	53,547	26,854	(3,991)
Other liabilities	(106,022)	(34,005)	(57,873)
Tenant leasing costs	(96,103)	(90,396)	(99,076)
Total adjustments	466,897	(507)	169,496
Net cash provided by operating activities	1,036,874	799,411	695,553
Cash flows from investing activities:
Acquisitions of real estate	(78,000)	0	(4,670)
Construction in progress	(500,350)	(374,664)	(405,942)
Building and other capital improvements	(150,640)	(112,755)	(82,479)
Tenant improvements	(230,298)	(144,572)	(106,003)
Proceeds from sales of real estate	122,750	602,600	419,864
Proceeds from sales of real estate and sales of interests in property partnerships placed in escrow	(122,647)	(200,612)	(1,912,347)
Proceeds from sales of real estate and sales of interests in property partnerships released from escrow	122,647	634,165	1,478,794
Cash placed in escrow for land sale contracts	0	(7,111)	0
Cash released from scrow for land sale contracts	1,596	5,312	0
Cash released from escrow for investing activities	6,694	0	0
Capital contributions to unconsolidated joint ventures	(575,795)	(38,207)	(52,052)
Capital distributions from unconsolidated joint ventures	20,440	24,527	1,491
Proceeds from sale of investment in unconsolidated joint venture	55,707	0	0
Investments in marketable securities	0	(667,335)	0
Investments in securities, net	(1,161)	(1,574)	(1,780)
Net cash used in investing activities	(1,329,057)	(280,226)	(665,124)
Cash flows from financing activities:
Repayments of mortgage notes payable	(1,326,865)	(54,801)	(87,758)
Proceeds from unsecured senior notes	1,989,790	0	0
Redemption/repurchase of unsecured senior notes	0	0	(548,016)
Redemption/repurchase of unsecured exchangeable senior notes	0	0	(654,521)
Borrowings on unsecured line of credit	25,000	0	0
Repayments of unsecured line of credit	(25,000)	0	0
Payments on capital lease obligations	(745)	(356)	0
Proceeds from real estate financing transaction	0	6,000	14,523
Payments on real estate financing transactions	(5,260)	(3,103)	(234)
Deferred financing costs	(16,121)	(1,510)	(31)
Net proceeds from equity transactions	(271)	799	1,923
Redemption of preferred units	0	(633)	(17,373)
Dividends and distributions	(671,626)	(1,226,199)	(840,264)
Sales of interests in property partnerships and contributions from noncontrolling interests in property partnerships	11,951	2,705	1,536,382
Acquisition of noncontrolling interest in property partnership	0	(108,499)	0
Distributions to noncontrolling interest in property partnerships	(55,474)	(172,949)	(37,118)
Net cash used in financing activities	(74,621)	(1,558,546)	(632,487)
Net decrease in cash and cash equivalents	(366,804)	(1,039,361)	(602,058)
Cash and cash equivalents, beginning of year	723,718	1,763,079	2,365,137
Cash and cash equivalents, end of year	356,914	723,718	1,763,079
Supplemental disclosures:
Cash paid for interest	433,591	481,826	646,516
Interest capitalized	39,237	34,213	52,476
Non-cash investing and financing activities:
Write off of fully depreciated real estate	(206,721)	(45,455)	(46,943)
Change in real estate included in accounts payable and accrued expenses	(1,481)	74,985	(1,431)
Real estate acquired through capital lease	21,000	0	0
Marketable securities transferred in connection with the legal defeasance of mortgage note payable	0	667,335	0
Mortgage note payable legally defeased	0	640,500	0
Mortgage note payable assigned in connection with the sale of real estate	0	116,993	0
Dividends and distributions declared but not paid	130,308	327,320	882,472
Conversions of redeemable partnership units to partners’ capital / stockholders equity	6,461	14,343	2,700
Conversion of redeemable preferred units to common units	0	0	33,306
Issuance of restricted securities to employees and directors	33,615	43,355	27,445
Boston Properties Limited Partnership
Net income	583,773	809,109	541,213
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	682,776	631,549	620,064
Impairment loss	1,783	0	0
Non-cash compensation expense	32,911	29,183	28,099
Income from unconsolidated joint ventures	(8,074)	(22,770)	(12,769)
Gain on sale of investment in unconsolidated joint venture	(59,370)	0	0
Distributions of net cash flow from operations of unconsolidated joint ventures	24,955	8,469	7,372
Losses (gains) on investments in securities	(2,273)	653	(1,038)
Non-cash portion of interest expense	(35,052)	(42,271)	(39,343)
Settlement of accreted debt discount on repurchases/repayments of unsecured senior notes and unsecured exchangeable senior notes	0	0	(94,963)
Losses from early extinguishments of debt	371	21,837	0
Gains on sales of real estate	(82,775)	(377,093)	(174,686)
Change in assets and liabilities:
Cash held in escrows	2,277	(18,284)	3,433
Tenant and other receivables, net	3,688	(46,326)	12,869
Accrued rental income, net	(28,127)	(73,911)	(57,899)
Prepaid expenses and other assets	52,923	(16,877)	20,238
Accounts payable and accrued expenses	15,666	(6,310)	3,903
Accrued interest payable	53,547	26,854	(3,991)
Other liabilities	(106,022)	(34,005)	(57,873)
Tenant leasing costs	(96,103)	(90,396)	(99,076)
Total adjustments	453,101	(9,698)	154,340
Net cash provided by operating activities	1,036,874	799,411	695,553
Cash flows from investing activities:
Acquisitions of real estate	(78,000)	0	(4,670)
Construction in progress	(500,350)	(374,664)	(405,942)
Building and other capital improvements	(150,640)	(112,755)	(82,479)
Tenant improvements	(230,298)	(144,572)	(106,003)
Proceeds from sales of real estate	122,750	602,600	419,864
Proceeds from sales of real estate and sales of interests in property partnerships placed in escrow	(122,647)	(200,612)	(1,912,347)
Proceeds from sales of real estate and sales of interests in property partnerships released from escrow	122,647	634,165	1,478,794
Cash placed in escrow for land sale contracts	0	(7,111)	0
Cash released from scrow for land sale contracts	1,596	5,312	0
Cash released from escrow for investing activities	6,694	0	0
Capital contributions to unconsolidated joint ventures	(575,795)	(38,207)	(52,052)
Capital distributions from unconsolidated joint ventures	20,440	24,527	1,491
Proceeds from sale of investment in unconsolidated joint venture	55,707	0	0
Investments in marketable securities	0	(667,335)	0
Investments in securities, net	(1,161)	(1,574)	(1,780)
Net cash used in investing activities	(1,329,057)	(280,226)	(665,124)
Cash flows from financing activities:
Repayments of mortgage notes payable	(1,326,865)	(54,801)	(87,758)
Proceeds from unsecured senior notes	1,989,790	0	0
Redemption/repurchase of unsecured senior notes	0	0	(548,016)
Redemption/repurchase of unsecured exchangeable senior notes	0	0	(654,521)
Borrowings on unsecured line of credit	25,000	0	0
Repayments of unsecured line of credit	(25,000)	0	0
Payments on capital lease obligations	(745)	(356)	0
Proceeds from real estate financing transaction	0	6,000	14,523
Payments on real estate financing transactions	(5,260)	(3,103)	(234)
Deferred financing costs	(16,121)	(1,510)	(31)
Net proceeds from equity transactions	(271)	799	1,923
Redemption of preferred units	0	(633)	(17,373)
Dividends and distributions	(671,626)	(1,226,199)	(840,264)
Sales of interests in property partnerships and contributions from noncontrolling interests in property partnerships	11,951	2,705	1,536,382
Acquisition of noncontrolling interest in property partnership	0	(108,499)	0
Distributions to noncontrolling interest in property partnerships	(55,474)	(172,949)	(37,118)
Net cash used in financing activities	(74,621)	(1,558,546)	(632,487)
Net decrease in cash and cash equivalents	(366,804)	(1,039,361)	(602,058)
Cash and cash equivalents, beginning of year	723,718	1,763,079	2,365,137
Cash and cash equivalents, end of year	356,914	723,718	1,763,079
Supplemental disclosures:
Cash paid for interest	433,591	481,826	646,516
Interest capitalized	39,237	34,213	52,476
Non-cash investing and financing activities:
Write off of fully depreciated real estate	(202,388)	(45,455)	(46,419)
Change in real estate included in accounts payable and accrued expenses	(1,481)	74,985	(1,431)
Real estate acquired through capital lease	21,000	0	0
Marketable securities transferred in connection with the legal defeasance of mortgage note payable	0	667,335	0
Mortgage note payable legally defeased	0	640,500	0
Mortgage note payable assigned in connection with the sale of real estate	0	116,993	0
Dividends and distributions declared but not paid	130,308	327,320	882,472
Conversions of redeemable partnership units to partners’ capital / stockholders equity	6,461	14,343	2,700
Conversion of redeemable preferred units to common units	0	0	33,306
Issuance of restricted securities to employees and directors	$ 33,615	$ 43,355	$ 27,445