Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income	$ 362,764	$ 403,238	$ 212,615
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	209,993	204,748	194,905
Equity in net gain on sale of interest in unconsolidated joint venture	0	(85,559)	(2,056)
Equity in net income from unconsolidated joint venture	(8,841)	(4,491)	17,108
Distributions of cumulative earnings from unconsolidated joint ventures	8,621	6,269	3,942
Loss on early extinguishment of debt	49	7,385	76
Depreciable real estate reserve	9,998	0	0
Gain on sale of real estate	(100,190)	0	0
Gain on sale of discontinued operations	0	(117,579)	(13,756)
Deferred rents receivable	(21,378)	(23,515)	(22,094)
Other non-cash adjustments	(64,329)	(87,271)	(103,179)
Changes in operating assets and liabilities:
Restricted cash—operations	(1,182)	(4,986)	(6,892)
Tenant and other receivables	(9,900)	(1,238)	4,545
Deferred lease costs	(38,623)	(21,103)	(26,263)
Other assets	14,558	10,710	(330)
Related party payable	0	0	(8,717)
Accounts payable, accrued expenses and other liabilities	2,458	(4,866)	(113)
Deferred revenue and land leases payable	1,487	1,653	4,624
Net cash provided by operating activities	365,485	283,395	254,415
Investing Activities
Acquisitions of real estate property	(109,633)	(517,535)	(386,775)
Additions to land, buildings and improvements	(89,998)	(102,905)	(97,918)
Escrowed cash—capital improvements/acquisition deposits	593	657	(193)
Investments in unconsolidated joint venture	(988)	(59,400)	(13,179)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	28,459	0	19,926
Net proceeds from disposition of real estate/joint venture interest	238,083	237,059	211,048
Other investments	(54,475)	(16,300)	(86,145)
Origination of debt and preferred equity investments	(758,133)	(617,090)	(555,137)
Repayments or redemption of preferred equity investments	520,218	576,927	657,765
Net cash used in investing activities	(225,874)	(498,587)	(250,608)
Financing Activities
Proceeds from mortgages and other loans payable	360,018	221,216	60,172
Repayments of mortgages and other loans payable	(326,594)	(608,539)	(95,950)
Proceeds from credit facility and senior unsecured notes	2,515,000	1,908,000	1,163,938
Repayments of credit facility and senior unsecured notes	(1,706,007)	(1,385,898)	(1,014,000)
Payments of debt extinguishment costs	0	(6,693)	0
Contributions from common unitholder	3,201,654	3,693,440	3,059,766
Contributions to noncontrolling interests in other partnerships	9,400	93	0
Distributions to noncontrolling interests in other partnerships	(1,865)	(5,199)	(12,088)
Distributions to common and preferred unitholder	(4,191,371)	(3,611,900)	(3,153,197)
Deferred loan costs and capitalized lease obligation	(9,511)	(3,681)	(609)
Other obligation related to mortgage loan participation	25,000	0	0
Net cash (used in) provided by financing activities	(124,276)	200,839	8,032
Net increase (decrease) in cash and cash equivalents	15,335	(14,353)	11,839
Cash and cash equivalents at beginning of year	34,691	49,044	37,205
Cash and cash equivalents at end of year	50,026	34,691	49,044
Supplemental Cash Flow Disclosure
Interest paid	118,090	138,574	139,216
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Tenant improvements and capital expenditures payable	3,441	375	1,479
Deferred leasing payable	7,752	11,127	2,655
Capital leased asset	0	0	10,657
Change in fair value of hedge	570	519	588
Contributions from common unitholder	13,928	4,000	7,338
Deconsolidation of a subsidiary	27,435	0	0
Issuance of SL Green common stock to a consolidated joint venture	10,000	0	0
Contribution of notes receivable from the common unit holder	90,000	0	0
Issuance of preferred units through a subsidiary	109,161	0	0
Contributions from a noncontrolling interest in other partnerships	22,278	0	0
Transfer of financing receivable to debt investment	$ 0	$ 19,675	$ 0