Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015
Operating Activities
Net income	$ 224,941		$ 203,210
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	737,195		473,817
Equity in net income from unconsolidated joint ventures	(11,969)		(10,651)
Distributions of cumulative earnings from unconsolidated joint ventures	19,311		33,141
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(43,588)		(16,050)
Depreciable real estate reserves	10,387		19,226
Gain on sale of real estate	(210,750)		(159,704)
Gain on sale of discontinued operations	0		(12,983)
Loss on sale of investment in marketable securities	83		0
Loss on early extinguishment of debt	0		49
Deferred rents receivable	40,056		(99,015)
Other non-cash adjustments	(155,558)	[1]	(16,140)
Changes in operating assets and liabilities:
Restricted cash—operations	(12,855)		(23,437)
Tenant and other receivables	2,714		(8,498)
Related party receivables	(4,167)		646
Deferred lease costs	(47,036)		(46,673)
Other assets	(30,899)		(43,736)
Accounts payable, accrued expenses and other liabilities and security deposits	(28,089)		6,119
Deferred revenue and land leases payable	19,016		23,678
Net cash provided by operating activities	508,792		322,999
Investing Activities
Acquisitions of real estate property	(38,005)		(2,574,687)
Additions to land, buildings and improvements	(269,182)		(219,760)
Escrowed cash—capital improvements/acquisition deposits/deferred purchase price	85,983		(117,026)
Investments in unconsolidated joint ventures	(69,422)		(127,783)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	171,472		89,059
Net proceeds from disposition of real estate/joint venture interest	2,419,841		1,072,175
Proceeds from sale of marketable securities	6,868		432
Purchases of marketable securities	(23,062)		(7,769)
Other investments	8,232		(11,894)
Origination of debt and preferred equity investments	(554,803)		(461,257)
Repayments or redemption of debt and preferred equity investments	667,251		372,084
Net cash provided by (used in) investing activities	2,405,173		(1,986,426)
Financing Activities
Proceeds from mortgages and other loans payable	256,207		1,706,018
Repayments of mortgages and other loans payable	(1,786,034)		(681,286)
Proceeds from revolving credit facility and senior unsecured notes	1,260,300		2,130,000
Repayments of revolving credit facility and senior unsecured notes	(2,269,604)		(1,466,007)
Proceeds from stock options exercised and DRIP issuance	12,404		112,399
Proceeds from sale of common stock	0		124,794
Redemption of preferred stock	(2,999)		(200)
Distributions to noncontrolling interests in other partnerships	(11,023)		(113,595)
Contributions from noncontrolling interests in other partnerships	2,019		11,931
Distributions to noncontrolling interests in the Operating Partnership	(9,245)		(7,017)
Dividends/Distributions paid on common and preferred stock/units	(234,801)		(191,920)
Other obligations related to mortgage loan participations	59,150		25,000
Deferred loan costs and capitalized lease obligation	(39,842)		(23,739)
Net cash (used in) provided by financing activities	(2,763,468)		1,626,378
Net increase (decrease) in cash and cash equivalents	150,497		(37,049)
Cash and cash equivalents at beginning of year	255,399		281,409
Cash and cash equivalents at end of period	405,896		244,360
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of units in the Operating Partnership relating to the investment in unconsolidated joint ventures	51,647		0
Redemption of units in the Operating Partnership for stock	12,746		41,605
Exchange of debt investment for equity in joint venture	68,581		10,151
Transfer of restricted cash to operating cash and cash equivalents as a result of sale	0		21,578
Acquisition of subsidiary interest from noncontrolling interest	0		20,630
Tenant improvements and capital expenditures payable	4,281		14,470
Fair value adjustment to noncontrolling interest in Operating Partnership	4,959		31,664
Capital lease assets	0		20,000
Reclassification of development costs from other assets to real estate	0		47,519
Transfer of assets related to assets held for sale	2,048,376		117,885
Transfer of liabilities related to assets held for sale	1,677,528		94
Deferred leasing payable	1,208		6,176
Removal of fully depreciated commercial real estate properties	22,179		0
Deconsolidation of a subsidiary (2)	1,173,570	[2]	27,435
Issuance of common stock to consolidated joint venture	114,049		10,000
Contribution to consolidated joint venture by noncontrolling interest	0		22,504
Receivable from sale of unconsolidated joint venture interest	0		15,129
SL Green Operating Partnership
Operating Activities
Net income	224,941		203,210
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	737,195		473,817
Equity in net income from unconsolidated joint ventures	(11,969)		(10,651)
Distributions of cumulative earnings from unconsolidated joint ventures	19,311		33,141
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(43,588)		(16,050)
Depreciable real estate reserves	10,387		19,226
Gain on sale of real estate	(210,750)		(159,704)
Gain on sale of discontinued operations	0		(12,983)
Loss on sale of investment in marketable securities	83		0
Loss on early extinguishment of debt	0		49
Deferred rents receivable	40,056		(99,015)
Other non-cash adjustments	(155,558)		(16,140)
Changes in operating assets and liabilities:
Restricted cash—operations	(12,855)		(23,437)
Tenant and other receivables	2,714		(8,498)
Related party receivables	(4,167)		646
Deferred lease costs	(47,036)		(46,673)
Other assets	(30,899)		(43,736)
Accounts payable, accrued expenses and other liabilities and security deposits	(28,089)		6,119
Deferred revenue and land leases payable	19,016		23,678
Net cash provided by operating activities	508,792		322,999
Investing Activities
Acquisitions of real estate property	(38,005)		(2,574,687)
Additions to land, buildings and improvements	(269,182)		(219,760)
Escrowed cash—capital improvements/acquisition deposits/deferred purchase price	85,983		(117,026)
Investments in unconsolidated joint ventures	(69,422)		(127,783)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	171,472		89,059
Net proceeds from disposition of real estate/joint venture interest	2,419,841		1,072,175
Proceeds from sale of marketable securities	6,868		432
Purchases of marketable securities	(23,062)		(7,769)
Other investments	8,232		(11,894)
Origination of debt and preferred equity investments	(554,803)		(461,257)
Repayments or redemption of debt and preferred equity investments	667,251		372,084
Net cash provided by (used in) investing activities	2,405,173		(1,986,426)
Financing Activities
Proceeds from mortgages and other loans payable	256,207		1,706,018
Repayments of mortgages and other loans payable	(1,786,034)		(681,286)
Proceeds from revolving credit facility and senior unsecured notes	1,260,300		2,130,000
Repayments of revolving credit facility and senior unsecured notes	(2,269,604)		(1,466,007)
Proceeds from stock options exercised and DRIP issuance	12,404		112,399
Proceeds from sale of common stock	0		124,794
Redemption of preferred stock	(2,999)		(200)
Distributions to noncontrolling interests in other partnerships	(11,023)		(113,595)
Contributions from noncontrolling interests in other partnerships	2,019		11,931
Dividends/Distributions paid on common and preferred stock/units	(244,046)		(198,937)
Other obligations related to mortgage loan participations	59,150		25,000
Deferred loan costs and capitalized lease obligation	(39,842)		(23,739)
Net cash (used in) provided by financing activities	(2,763,468)		1,626,378
Net increase (decrease) in cash and cash equivalents	150,497		(37,049)
Cash and cash equivalents at beginning of year	255,399		281,409
Cash and cash equivalents at end of period	405,896		244,360
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of units in the Operating Partnership relating to the investment in unconsolidated joint ventures	51,647		0
Redemption of units in the Operating Partnership for stock	12,746		41,605
Exchange of debt investment for equity in joint venture	68,581		10,151
Transfer of restricted cash to operating cash and cash equivalents as a result of sale	0		21,578
Acquisition of subsidiary interest from noncontrolling interest	0		20,630
Tenant improvements and capital expenditures payable	4,281		14,470
Capital lease assets	0		20,000
Reclassification of development costs from other assets to real estate	0		47,519
Transfer of assets related to assets held for sale	2,048,376		117,885
Transfer of liabilities related to assets held for sale	1,677,528		94
Deferred leasing payable	1,208		6,176
Removal of fully depreciated commercial real estate properties	22,179		0
Deconsolidation of a subsidiary (2)	1,173,570	[2]	27,435
Issuance of common stock to consolidated joint venture	114,049		10,000
Contribution to consolidated joint venture by noncontrolling interest	0		22,504
Receivable from sale of unconsolidated joint venture interest	0		15,129
Common Stock
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units	0		2,228
Common Stock | SL Green Operating Partnership
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units	0		2,228
Preferred Units
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of preferred units relating to a real estate acquisition	22,793		211,601
Preferred Units | SL Green Operating Partnership
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of preferred units relating to a real estate acquisition	$ 22,793		$ 211,601

[1] Included in Other non-cash adjustments is $172.4 million for the nine months ended September 30, 2016 for the amortization of the below-market lease at 388-390 Greenwich Street as a result of the tenant exercising their option to purchase the property and entering into an agreement to accelerate the sale

[2] The 2016 amount relates to 11 Madison for which in August 2016 we closed on the sale of a 40% interest. The sale did not meet the criteria for sale accounting and as a result the property is being accounted for under the profit sharing method.