SL Green Realty (SLG) 10-Q 9 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 02, 2015
Document Information [Line Items]
Entity Registrant Name	SL GREEN REALTY CORP
Entity Central Index Key	1,040,971
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		99,703,055
SL Green Operating Partnership
Document Information [Line Items]
Entity Registrant Name	SL GREEN OPERATING PARTNERSHIP, LP.
Entity Central Index Key	1,492,869
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		1,005,301

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Commercial real estate properties, at cost:
Land and land interests	$ 4,689,031	$ 3,844,518
Building and improvements	10,079,151	8,778,593
Building leasehold and improvements	1,425,299	1,418,585
Properties under capital lease	47,445	27,445
Total commercial real estate properties, at cost	16,240,926	14,069,141
Less: accumulated depreciation	(1,979,824)	(1,905,165)
Total commercial real estate properties, net	14,261,102	12,163,976
Assets held for sale	117,885	462,430
Cash and cash equivalents	244,360	281,409
Restricted cash	279,592	149,176
Investment in marketable securities	46,432	39,429
Tenant and other receivables, net of allowance of $15,712 and $18,068 in 2015 and 2014, respectively	66,896	57,369
Related party receivables	11,089	11,735
Deferred rents receivable, net of allowance of $22,190 and $27,411 in 2015 and 2014, respectively	467,627	374,944
Debt and preferred equity investments, net of discounts and deferred origination fees of $16,169 and $19,172 in 2015 and 2014, respectively	1,501,619	1,408,804
Investments in unconsolidated joint ventures	1,239,008	1,172,020
Deferred costs, net	342,936	327,962
Other assets	912,023	647,333
Total assets	19,490,569	17,096,587
Liabilities
Mortgages and other loans payable	6,865,383	5,586,709
Revolving credit facility	949,000	385,000
Term loan and senior unsecured notes	2,216,120	2,107,078
Accrued interest payable and other liabilities	204,224	137,634
Accounts payable and accrued expenses	173,228	173,246
Deferred revenue	428,334	187,148
Capital lease obligations	41,171	20,822
Deferred land leases payable	1,557	1,215
Dividend and distributions payable	67,109	64,393
Security deposits	66,654	66,614
Liabilities related to assets held for sale	94	266,873
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities	100,000	100,000
Total liabilities	$ 11,112,874	$ 9,096,732
Commitments and contingencies
Noncontrolling interests in Operating Partnership	$ 423,421	$ 469,524
Preferred units	282,516	71,115
Equity
Common stock, $0.01 par value, 160,000 shares authorized and 103,383 and 100,928 issued and outstanding at September 30, 2015 and December 31, 2014, respectively (including 3,724 and 3,603 shares held in Treasury at September 30, 2015 and December 31, 2014, respectively)	1,034	1,010
Additional paid-in-capital	5,593,653	5,289,479
Treasury stock at cost	(335,311)	(320,471)
Accumulated other comprehensive loss	(15,821)	(6,980)
Retained earnings	1,772,833	1,752,404
Total SL Green stockholders' equity	7,238,320	6,937,374
Noncontrolling interests in other partnerships	433,438	521,842
Total equity	7,671,758	7,459,216
SL Green stockholders equity:
Total liabilities and equity/capital	19,490,569	17,096,587
Series I Preferred Stock
Equity
Series I Preferred Stock, $0.01 par value, $25.00 liquidation preference, 9,200 issued and outstanding at both September 30, 2015 and December 31, 2014	221,932	221,932
SL Green Operating Partnership
Commercial real estate properties, at cost:
Land and land interests	4,689,031	3,844,518
Building and improvements	10,079,151	8,778,593
Building leasehold and improvements	1,425,299	1,418,585
Properties under capital lease	47,445	27,445
Total commercial real estate properties, at cost	16,240,926	14,069,141
Less: accumulated depreciation	(1,979,824)	(1,905,165)
Total commercial real estate properties, net	14,261,102	12,163,976
Assets held for sale	117,885	462,430
Cash and cash equivalents	244,360	281,409
Restricted cash	279,592	149,176
Investment in marketable securities	46,432	39,429
Tenant and other receivables, net of allowance of $15,712 and $18,068 in 2015 and 2014, respectively	66,896	57,369
Related party receivables	11,089	11,735
Deferred rents receivable, net of allowance of $22,190 and $27,411 in 2015 and 2014, respectively	467,627	374,944
Debt and preferred equity investments, net of discounts and deferred origination fees of $16,169 and $19,172 in 2015 and 2014, respectively	1,501,619	1,408,804
Investments in unconsolidated joint ventures	1,239,008	1,172,020
Deferred costs, net	342,936	327,962
Other assets	912,023	647,333
Total assets	19,490,569	17,096,587
Liabilities
Mortgages and other loans payable	6,865,383	5,586,709
Revolving credit facility	949,000	385,000
Term loan and senior unsecured notes	2,216,120	2,107,078
Accrued interest payable and other liabilities	204,224	137,634
Accounts payable and accrued expenses	173,228	173,246
Deferred revenue	428,334	187,148
Capital lease obligations	41,171	20,822
Deferred land leases payable	1,557	1,215
Dividend and distributions payable	67,109	64,393
Security deposits	66,654	66,614
Liabilities related to assets held for sale	94	266,873
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities	100,000	100,000
Total liabilities	$ 11,112,874	$ 9,096,732
Commitments and contingencies
Preferred units	$ 282,516	$ 71,115
Equity
Accumulated other comprehensive loss	(16,446)	(7,256)
SL Green stockholders equity:
SL Green partners' capital (1,035 and 1,013 general partner common units and 98,624 and 96,312 limited partner common units outstanding at September 30, 2015 and December 31, 2014, respectively)	7,357,047	7,078,924
Limited partner interests in SLGOP (3,875 and 3,973 limited partner common units outstanding at September 30, 2015 and December 31, 2014, respectively)	99,208	113,298
Total SLGOP partners' capital	7,661,741	7,406,898
Noncontrolling interests in other partnerships	433,438	521,842
Total capital	8,095,179	7,928,740
Total liabilities and equity/capital	19,490,569	17,096,587
SL Green Operating Partnership | Series I Preferred Stock
SL Green stockholders equity:
Series I Preferred Units, $25.00 liquidation preference, 9,200 issued and outstanding at both September 30, 2015 and December 31, 2014	221,932	221,932
Total capital	$ 221,932	$ 221,932

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Tenant and other receivables, allowance	$ 15,712	$ 18,068
Deferred rents receivable, allowance	22,190	27,411
Debt and preferred equity investments, discount	$ 16,169	$ 19,172
Preferred stock, par value (in dollars per share)	$ 0.01
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	160,000,000	160,000,000
Common stock, shares issued	103,383,000	100,928,000
Common stock, shares outstanding	103,383,000	100,928,000
Treasury stock, shares	3,724,000	3,603,000
Series I Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred stock, shares issued	9,200,000	9,200,000
Preferred stock, shares outstanding	9,200,000	9,200,000
SL Green Operating Partnership
Tenant and other receivables, allowance	$ 15,712	$ 18,068
Deferred rents receivable, allowance	22,190	27,411
Debt and preferred equity investments, discount	$ 16,169	$ 19,172
SL Green partner's capital, general partner common units outstanding (shares)	1,035,000	1,013,000
SL Green partners' capital, limited partner common units outstanding (shares)	98,624,000	96,312,000
Limited partner interests in Operating Partnership, limited partner common units outstanding (shares)	3,875,000	3,973,000
SL Green Operating Partnership | Series I Preferred Stock
Preferred units, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred units, shares issued	9,200,000	9,200,000
Preferred units, shares outstanding	9,200,000	9,200,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues
Rental revenue, net	$ 318,465	$ 291,293	$ 926,020	$ 826,877
Escalation and reimbursement	48,254	43,826	130,630	120,209
Investment income	49,328	43,969	136,588	137,767
Other income	16,019	11,186	44,201	48,498
Total revenues	432,066	390,274	1,237,439	1,133,351
Expenses
Operating expenses, including $5,238 and $13,415 in 2015 and $5,104 and $13,183 in 2014 of related party expenses	78,648	72,111	225,539	211,118
Real estate taxes	61,009	55,548	173,018	159,702
Ground rent	8,252	8,088	24,526	24,161
Interest expense, net of interest income	84,141	82,376	235,694	236,424
Amortization of deferred financing costs	7,160	6,679	19,727	15,737
Depreciation and amortization	146,185	94,443	454,087	274,337
Transaction related costs	5,829	2,383	10,039	6,554
Marketing, general and administrative	23,475	22,649	72,139	69,778
Total expenses	414,699	344,277	1,214,769	997,811
Income from continuing operations before equity in net income from unconsolidated joint ventures, equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate, depreciable real estate reserves and loss on early extinguishment of debt	17,367	45,997	22,670	135,540
Equity in net income from unconsolidated joint ventures	3,627	6,034	10,651	20,781
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,281	16,496	16,050	122,580
Purchase price fair value adjustment	0	(4,000)	0	67,446
Gain on sale of real estate	159,704	0	159,704	0
Depreciable real estate reserves	(19,226)	0	(19,226)	0
Loss on early extinguishment of debt	0	(24,475)	(49)	(25,500)
Income from continuing operations	176,753	40,052	189,800	320,847
Net income from discontinued operations	0	4,035	427	15,449
Gain on sale of discontinued operations	0	29,507	12,983	144,242
Net income	176,753	73,594	203,210	480,538
Net income attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(6,467)	(2,636)	(6,634)	(16,010)
Net income attributable to noncontrolling interests in other partnerships	(665)	(1,712)	(13,217)	(5,045)
Preferred units distributions	(2,225)	(820)	(4,316)	(1,950)
Net income attributable to SL Green/SLGOP	167,396	68,426	179,043	457,533
Perpetual preferred stock dividends	(3,738)	(3,738)	(11,214)	(11,214)
Amounts attributable to SL Green common stockholders:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	13,768	20,312	4,357	108,710
Purchase price fair value adjustment	0	(3,856)	0	65,111
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	14,705	15,901	15,439	118,336
Net income from discontinued operations	0	3,889	411	14,914
Gain on sale of discontinued operations	0	28,442	12,489	139,248
Gain on sale of real estate	153,687	0	153,628	0
Depreciable real estate reserves	(18,502)	0	(18,495)	0
Net income attributable to SL Green common stockholders	$ 163,658	$ 64,688	$ 167,829	$ 446,319
Basic earnings per share:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	$ 0.14	$ 0.21	$ 0.04	$ 1.14
Purchase price fair value adjustment (usd per share)	0	(0.04)	0	0.68
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	0.17	0.16	1.24
Net income from discontinued operations (usd per share)	0	0.04	0	0.16
Gain on sale of discontinued operations (usd per share)	0	0.30	0.13	1.46
Gain on sale of real estate (in dollars per share)	1.54	0	1.55	0
Depreciable Real Estate Reserves, Effect on Earnings, Per Basic Share	(0.19)	0	(0.19)	0
Net income attributable to SL Green common stockholders (usd per share)	1.64	0.68	1.69	4.68
Diluted earnings per share:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	0.14	0.21	0.04	1.14
Purchase price fair value adjustment (usd per share)	0	(0.04)	0	0.68
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	0.17	0.16	1.23
Net income from discontinued operations (usd per share)	0	0.04	0	0.16
Gain on sale of discontinued operations (usd per share)	0	0.30	0.13	1.45
Gain on sale of real estate (in dollars per share)	1.54	0	1.54	0
Depreciable Real Estate Reserves, Effect on Earnings, Per Diluted Share	(0.19)	0	(0.19)	0
Net income attributable to SL Green common stockholders (usd per share)	1.64	0.68	1.68	4.66
Dividends per share/unit (usd per share)	$ 0.60	$ 0.5	$ 1.80	$ 1.50
Basic weighted average common shares outstanding (in shares)	99,621	95,734	99,205	95,437
Diluted weighted average common shares and common share equivalents outstanding (in shares)	103,929	99,706	103,609	99,322
SL Green Operating Partnership
Revenues
Rental revenue, net	$ 318,465	$ 291,293	$ 926,020	$ 826,877
Escalation and reimbursement	48,254	43,826	130,630	120,209
Investment income	49,328	43,969	136,588	137,767
Other income	16,019	11,186	44,201	48,498
Total revenues	432,066	390,274	1,237,439	1,133,351
Expenses
Operating expenses, including $5,238 and $13,415 in 2015 and $5,104 and $13,183 in 2014 of related party expenses	78,648	72,111	225,539	211,118
Real estate taxes	61,009	55,548	173,018	159,702
Ground rent	8,252	8,088	24,526	24,161
Interest expense, net of interest income	84,141	82,376	235,694	236,424
Amortization of deferred financing costs	7,160	6,679	19,727	15,737
Depreciation and amortization	146,185	94,443	454,087	274,337
Transaction related costs	5,829	2,383	10,039	6,554
Marketing, general and administrative	23,475	22,649	72,139	69,778
Total expenses	414,699	344,277	1,214,769	997,811
Income from continuing operations before equity in net income from unconsolidated joint ventures, equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate, depreciable real estate reserves and loss on early extinguishment of debt	17,367	45,997	22,670	135,540
Equity in net income from unconsolidated joint ventures	3,627	6,034	10,651	20,781
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,281	16,496	16,050	122,580
Purchase price fair value adjustment	0	(4,000)	0	67,446
Gain on sale of real estate	159,704	0	159,704	0
Depreciable real estate reserves	(19,226)	0	(19,226)	0
Loss on early extinguishment of debt	0	(24,475)	(49)	(25,500)
Income from continuing operations	176,753	40,052	189,800	320,847
Net income from discontinued operations	0	4,035	427	15,449
Gain on sale of discontinued operations	0	29,507	12,983	144,242
Net income	176,753	73,594	203,210	480,538
Net income attributable to noncontrolling interests:
Net income attributable to noncontrolling interests in other partnerships	(665)	(1,712)	(13,217)	(5,045)
Preferred unit distributions	(2,225)	(820)	(4,316)	(1,950)
Net income attributable to SL Green/SLGOP	173,863	71,062	185,677	473,543
Perpetual preferred unit distributions	(3,738)	(3,738)	(11,214)	(11,214)
Net income attributable to SLGOP common unitholders	170,125	67,324	174,463	462,329
Amounts attributable to SL Green common stockholders:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	14,366	21,286	4,525	112,612
Purchase price fair value adjustment	0	(4,000)	0	67,446
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,281	16,496	16,050	122,580
Net income from discontinued operations	0	4,035	427	15,449
Gain on sale of discontinued operations	0	29,507	12,983	144,242
Gain on sale of real estate	159,704	0	159,704	0
Depreciable real estate reserves	$ (19,226)	$ 0	$ (19,226)	$ 0
Basic earnings per share:
Income from continuing operations before gains on sale and discontinued operations (usd per share)	$ 0.14	$ 0.21	$ 0.04	$ 1.14
Purchase price fair value adjustment (usd per share)	0	(0.04)	0	0.68
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	0.17	0.16	1.24
Net income from discontinued operations (usd per share)	0	0.04	0	0.16
Gain on sale of discontinued operations (usd per share)	0	0.30	0.13	1.46
Gain on sale of real estate (in dollars per share)	1.54	0	1.55	0
Depreciable Real Estate Reserves, Effect on Earnings, Per Basic Share	(0.19)	0	(0.19)	0
Net income attributable to SLGOP common unitholders (usd per share)	1.64	0.68	1.69	4.68
Diluted earnings per share:
Income from continuing operations before gains on sale and discontinued operations (usd per share)	0.14	0.21	0.04	1.14
Purchase price fair value adjustment (usd per share)	0	(0.04)	0	0.68
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	0.17	0.16	1.23
Net income from discontinued operations (usd per share)	0	0.04	0	0.16
Gain on sale of discontinued operations (usd per share)	0	0.30	0.13	1.45
Gain on sale of real estate (in dollars per share)	1.54	0	1.54	0
Depreciable Real Estate Reserves, Effect on Earnings, Per Diluted Share	(0.19)	0	(0.19)	0
Net income attributable to SLGOP common unitholders (usd per share)	1.64	0.68	1.68	4.66
Dividends per share/unit (usd per share)	$ 0.60	$ 0.50	$ 1.8	$ 1.50
Basic weighted average common units outstanding (in shares)	103,522	99,319	103,129	98,860
Diluted weighted average common units and common unit equivalents outstanding (in shares)	103,929	99,706	103,609	99,322

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Operating expenses, paid to related parties	$ 5,238	$ 5,104	$ 13,415	$ 13,183
SL Green Operating Partnership
Operating expenses, paid to related parties	$ 5,238	$ 5,104	$ 13,415	$ 13,183

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income	$ 176,753	$ 73,594	$ 203,210	$ 480,538
Other comprehensive income (loss):
Change in net unrealized (loss) gain on derivative instruments, including SL Green's/SLGOP's share of joint venture net unrealized (loss) gain on derivative instruments	(5,423)	3,919	(8,853)	11,380
Change in unrealized gain (loss) on marketable securities	317	(506)	(337)	1,282
Other comprehensive (loss) income	(5,106)	3,413	(9,190)	12,662
Comprehensive income	171,647	77,007	194,020	493,200
Net loss attributable to noncontrolling interests and preferred units distributions	(9,357)	(5,168)	(24,167)	(23,005)
Other comprehensive income (loss) attributable to noncontrolling interests	191	(113)	349	(347)
Comprehensive income attributable to SL Green/SLGOP	162,481	71,726	170,202	469,848
SL Green Operating Partnership
Net income	176,753	73,594	203,210	480,538
Other comprehensive income (loss):
Change in net unrealized (loss) gain on derivative instruments, including SL Green's/SLGOP's share of joint venture net unrealized (loss) gain on derivative instruments	(5,423)	3,919	(8,853)	11,380
Change in unrealized gain (loss) on marketable securities	317	(506)	(337)	1,282
Other comprehensive (loss) income	(5,106)	3,413	(9,190)	12,662
Comprehensive income	171,647	77,007	194,020	493,200
Net loss attributable to noncontrolling interests and preferred units distributions	(665)	(1,712)	(13,217)	(5,045)
Comprehensive income attributable to SL Green/SLGOP	$ 170,982	$ 75,295	$ 180,803	$ 488,155

Consolidated Statement of Equit

Consolidated Statement of Equity - 9 months ended Sep. 30, 2015 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid- In-Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings	Noncontrolling Interests	Series I Preferred StockPreferred Stock
Beginning Balance at Dec. 31, 2014	$ 7,459,216	$ 1,010	$ 5,289,479	$ (320,471)	$ (6,980)	$ 1,752,404	$ 521,842	$ 221,932
Beginning Balance (in shares) at Dec. 31, 2014		97,325
Increase (Decrease) in Stockholders' Equity
Net income	192,260					179,043	13,217
Acquisition of subsidiary interest from noncontrolling interest	(20,650)		(9,566)				(11,084)
Other comprehensive loss	(8,841)				(8,841)
Preferred dividends	(11,214)					(11,214)
DRSPP proceeds (in shares)		776
DRSPP proceeds	99,529	$ 8	99,521
Conversion of units of the Operating Partnership to common stock (in units)		353
Conversion of units of the Operating Partnership to common stock	41,605	$ 4	41,601
Reallocation of noncontrolling interest in the Operating Partnership	(31,664)					(31,664)
Reallocation of capital account relating to sale	(10,144)						(10,144)
Deferred compensation plan and stock award, net (in shares)		28
Deferred compensation plan and stock award, net	(3,096)	$ 0	1,744	(4,840)
Amortization of deferred compensation plan	20,994		20,994
Issuance of common stock (in shares)		1,007
Issuance of common stock	127,022	$ 10	137,012	(10,000)
Proceeds from stock options exercised (in shares)		170
Proceeds from stock options exercised	12,870	$ 2	12,868
Contributions from consolidated joint venture interests	34,435						34,435
Cash distributions to noncontrolling interests	(114,828)						(114,828)
Cash distributions declared ($1.80 per common share, none of which represented a return of capital for federal income tax purposes)	(179,064)					(179,064)
Ending Balance at Sep. 30, 2015	$ 7,671,758	$ 1,034	$ 5,593,653	$ (335,311)	$ (15,821)	$ 1,772,833	$ 433,438	$ 221,932
Ending Balance (in shares) at Sep. 30, 2015		99,659

Consolidated Statement of Equi8

Consolidated Statement of Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Stockholders' Equity [Abstract]
Cash distribution declared, per common share (in dollars per share)	$ 0.60	$ 0.5	$ 1.80	$ 1.50

Consolidated Statement of Capit

Consolidated Statement of Capital Statement - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Increase (Decrease) in Partner's Capital
Acquisition of subsidiary interest from noncontrolling interest		$ (20,650)
Other comprehensive loss	$ (5,106)	(9,190)
Issuance of common units		27,898
DRSPP proceeds		99,529
Conversion of units of the Operating Partnership to common stock		41,605
Reallocation of capital account relating to sale		(10,144)
Deferred compensation plan and stock award, net		(3,096)
Amortization of deferred compensation plan		20,994
Cash distributions to noncontrolling interests		$ (114,828)
Common Stock
Increase (Decrease) in Partner's Capital
DRSPP proceeds (in shares)		776
DRSPP proceeds		$ 8
Conversion of units of the Operating Partnership to common stock (in units)		353
Conversion of units of the Operating Partnership to common stock		$ 4
Deferred compensation plan and stock award, net (in shares)		28
Deferred compensation plan and stock award, net		$ 0
Contributions - net proceeds from common stock offering (in shares)		1,007
Contributions - proceeds from stock options exercised (in shares)		170
Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Acquisition of subsidiary interest from noncontrolling interest		$ (11,084)
Reallocation of capital account relating to sale		(10,144)
Cash distributions to noncontrolling interests		(114,828)
SL Green Operating Partnership
Increase (Decrease) in Partner's Capital
Beginning Balance		7,928,740
Net income		198,894
Acquisition of subsidiary interest from noncontrolling interest		(20,650)
Other comprehensive loss	(5,106)	(9,190)
Preferred distributions		(11,214)
Issuance of common units		27,898
DRSPP proceeds		99,529
Conversion of units of the Operating Partnership to common stock		0
Reallocation of capital account relating to sale		(10,144)
Deferred compensation plan and stock award, net		(3,096)
Amortization of deferred compensation plan		20,994
Contribution to consolidated joint venture interest		34,435
Contributions - net proceeds from common stock offering		127,022
Contributions - proceeds from stock options exercised		12,870
Cash distributions to noncontrolling interests		(114,828)
Cash distributions declared ($1.80 per common unit, none of which represented a return of capital for federal income tax purposes)		(186,081)
Ending Balance	8,095,179	8,095,179
SL Green Operating Partnership | Series I Preferred Stock
Increase (Decrease) in Partner's Capital
Beginning Balance		221,932
Net income		11,214
Preferred distributions		(11,214)
Ending Balance	221,932	221,932
SL Green Operating Partnership | Common Stock | General Partner
Increase (Decrease) in Partner's Capital
Beginning Balance		$ 7,078,924
Beginning Balance (units)		97,325
Net income		$ 167,829
Acquisition of subsidiary interest from noncontrolling interest		$ (9,566)
DRSPP proceeds (in shares)		776
DRSPP proceeds		$ 99,529
Conversion of units of the Operating Partnership to common stock (in units)		353
Conversion of units of the Operating Partnership to common stock		$ 41,605
Deferred compensation plan and stock award, net (in shares)		28
Deferred compensation plan and stock award, net		$ (3,096)
Amortization of deferred compensation plan		$ 20,994
Contributions - net proceeds from common stock offering (in shares)		1,007
Contributions - net proceeds from common stock offering		$ 127,022
Contributions - proceeds from stock options exercised (in shares)		170
Contributions - proceeds from stock options exercised		$ 12,870
Cash distributions declared ($1.80 per common unit, none of which represented a return of capital for federal income tax purposes)		(179,064)
Ending Balance	$ 7,357,047	$ 7,357,047
Ending Balance (units)	99,659	99,659
SL Green Operating Partnership | Common Stock | Limited Partners
Increase (Decrease) in Partner's Capital
Beginning Balance		$ 113,298
Beginning Balance (units)		3,973
Net income		$ 6,634
Issuance of common units (in units)		255
Issuance of common units		$ 27,898
Conversion of units of the Operating Partnership to common stock (in units)		353
Conversion of units of the Operating Partnership to common stock		$ (41,605)
Cash distributions declared ($1.80 per common unit, none of which represented a return of capital for federal income tax purposes)		(7,017)
Ending Balance	$ 99,208	$ 99,208
Ending Balance (units)	3,875	3,875
SL Green Operating Partnership | Accumulated Other Comprehensive Loss
Increase (Decrease) in Partner's Capital
Beginning Balance		$ (7,256)
Other comprehensive loss		(9,190)
Ending Balance	$ (16,446)	(16,446)
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Beginning Balance		521,842
Net income		13,217
Acquisition of subsidiary interest from noncontrolling interest		(11,084)
Reallocation of capital account relating to sale		(10,144)
Contribution to consolidated joint venture interest		34,435
Cash distributions to noncontrolling interests		(114,828)
Ending Balance	$ 433,438	$ 433,438

Consolidated Statement of Cap10

Consolidated Statement of Capital (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Cash distribution declared, per common share (in dollars per share)	$ 0.60	$ 0.5	$ 1.80	$ 1.50
SL Green Operating Partnership
Cash distribution declared, per common share (in dollars per share)	$ 0.60	$ 0.50	$ 1.8	$ 1.50

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities
Net income	$ 203,210	$ 480,538
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	473,817	295,877
Equity in net income from unconsolidated joint ventures	(10,651)	(20,781)
Distributions of cumulative earnings from unconsolidated joint ventures	33,141	23,065
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(16,050)	(122,580)
Purchase price fair value adjustment	0	(71,446)
Depreciable real estate reserves	19,226	0
Gain on sale of real estate	(159,704)	0
Gain on sale of discontinued operations	(12,983)	(144,242)
Loss on early extinguishment of debt	49	25,500
Deferred rents receivable	(99,015)	(43,736)
Other non-cash adjustments	(16,140)	(25,705)
Changes in operating assets and liabilities:
Restricted cash—operations	(23,437)	(7,124)
Tenant and other receivables	(8,498)	(7,336)
Related party receivables	646	(5,200)
Deferred lease costs	(46,673)	(17,544)
Other assets	(43,736)	(23,133)
Accounts payable, accrued expenses and other liabilities and security deposits	6,119	17,445
Deferred revenue and land leases payable	23,678	23,608
Net cash provided by operating activities	322,999	377,206
Investing Activities
Acquisitions of real estate property	(2,574,687)	(711,437)
Additions to land, buildings and improvements	(219,760)	(282,947)
Escrowed cash—capital improvements/acquisition deposits/deferred purchase price	(117,026)	(67,868)
Investments in unconsolidated joint ventures	(127,783)	(217,187)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	89,059	158,809
Proceeds from disposition of real estate/joint venture interest	1,072,175	357,426
Proceeds from sale of marketable securities	432	3,669
Purchases of marketable securities	(7,769)	(10,025)
Other investments	(11,894)	15,980
Origination of debt and preferred equity investments	(461,257)	(421,003)
Repayments or redemption of debt and preferred equity investments	372,084	349,320
Net cash used in investing activities	(1,986,426)	(825,263)
Financing Activities
Proceeds from mortgages and other loans payable	1,706,018	2,001,603
Repayments of mortgages and other loans payable	(681,286)	(1,688,466)
Proceeds from revolving credit facility and senior unsecured notes	2,130,000	1,136,400
Repayments of revolving credit facility and senior unsecured notes	(1,466,007)	(805,988)
Payments of debt extinguishment costs	0	(23,332)
Proceeds from stock options exercised and DRSSP issuance	112,399	20,549
Proceeds from sale of common stock	124,794	42,698
Redemption of preferred unit	(200)	0
Distributions to noncontrolling interests in other partnerships	(113,595)	(5,745)
Contributions from noncontrolling interests in other partnerships	11,931	27,933
Distributions to noncontrolling interests in the Operating Partnership	(7,017)	(5,482)
Dividends/Distributions paid on common and preferred stock/units	(191,920)	(154,907)
Other obligations related to mortgage loan participations	25,000	0
Deferred loan costs and capitalized lease obligation	(23,739)	(50,378)
Net cash provided by financing activities	1,626,378	494,885
Net (decrease) increase in cash and cash equivalents	(37,049)	46,828
Cash and cash equivalents at beginning of year	281,409	206,692
Cash and cash equivalents at end of period	244,360	253,520
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of common stock as deferred compensation	1,744	1,503
Issuance of units in the Operating Partnership	27,898	22,862
Redemption of units in the Operating Partnership	41,605	26,392
Derivative instruments at fair value	5,459	12,713
Exchange of debt investment for equity in joint venture	10,151	0
Transfer of restricted cash to operating cash and cash equivalents as a result of sale	21,578	0
Acquisition of subsidiary interest from noncontrolling interest	20,630	0
Tenant improvements and capital expenditures payable	14,470	8,456
Fair value adjustment to noncontrolling interest in the Operating Partnership	31,664	108,453
Capital lease asset	20,000	0
Reclass of development costs from other assets to real estate	47,519	0
Transfer to net assets held for sale	117,885	753,457
Transfer to liabilities related to net assets held for sale	94	461,891
Transfer of financing receivable to debt investment	0	19,675
Deferred leasing payable	6,176	13,086
Consolidation of real estate	0	1,316,591
Issuance of common stock to consolidated joint venture	10,000	0
Contribution to consolidated joint venture by noncontrolling interest	22,504	0
Receivable from sale of unconsolidated joint venture interests	15,129	0
SL Green Operating Partnership
Operating Activities
Net income	203,210	480,538
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	473,817	295,877
Equity in net income from unconsolidated joint ventures	(10,651)	(20,781)
Distributions of cumulative earnings from unconsolidated joint ventures	33,141	23,065
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(16,050)	(122,580)
Purchase price fair value adjustment	0	(71,446)
Depreciable real estate reserves	19,226	0
Gain on sale of real estate	(159,704)	0
Gain on sale of discontinued operations	(12,983)	(144,242)
Loss on early extinguishment of debt	49	25,500
Deferred rents receivable	(99,015)	(43,736)
Other non-cash adjustments	(16,140)	(25,705)
Changes in operating assets and liabilities:
Restricted cash—operations	(23,437)	(7,124)
Tenant and other receivables	(8,498)	(7,336)
Related party receivables	646	(5,200)
Deferred lease costs	(46,673)	(17,544)
Other assets	(43,736)	(23,133)
Accounts payable, accrued expenses and other liabilities and security deposits	6,119	17,445
Deferred revenue and land leases payable	23,678	23,608
Net cash provided by operating activities	322,999	377,206
Investing Activities
Acquisitions of real estate property	(2,574,687)	(711,437)
Additions to land, buildings and improvements	(219,760)	(282,947)
Escrowed cash—capital improvements/acquisition deposits/deferred purchase price	(117,026)	(67,868)
Investments in unconsolidated joint ventures	(127,783)	(217,187)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	89,059	158,809
Proceeds from disposition of real estate/joint venture interest	1,072,175	357,426
Proceeds from sale of marketable securities	432	3,669
Purchases of marketable securities	(7,769)	(10,025)
Other investments	(11,894)	15,980
Origination of debt and preferred equity investments	(461,257)	(421,003)
Repayments or redemption of debt and preferred equity investments	372,084	349,320
Net cash used in investing activities	(1,986,426)	(825,263)
Financing Activities
Proceeds from mortgages and other loans payable	1,706,018	2,001,603
Repayments of mortgages and other loans payable	(681,286)	(1,688,466)
Proceeds from revolving credit facility and senior unsecured notes	2,130,000	1,136,400
Repayments of revolving credit facility and senior unsecured notes	(1,466,007)	(805,988)
Payments of debt extinguishment costs	0	(23,332)
Proceeds from stock options exercised and DRSSP issuance	112,399	20,549
Proceeds from sale of common stock	124,794	42,698
Redemption of preferred unit	(200)	0
Distributions to noncontrolling interests in other partnerships	(113,595)	(5,745)
Contributions from noncontrolling interests in other partnerships	11,931	27,933
Dividends/Distributions paid on common and preferred stock/units	(198,937)	(160,389)
Other obligations related to mortgage loan participations	25,000	0
Deferred loan costs and capitalized lease obligation	(23,739)	(50,378)
Net cash provided by financing activities	1,626,378	494,885
Net (decrease) increase in cash and cash equivalents	(37,049)	46,828
Cash and cash equivalents at beginning of year	281,409	206,692
Cash and cash equivalents at end of period	244,360	253,520
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of common stock as deferred compensation	1,744	1,503
Issuance of units in the Operating Partnership	27,898	22,862
Redemption of units in the Operating Partnership	41,605	26,392
Derivative instruments at fair value	5,459	12,713
Exchange of debt investment for equity in joint venture	10,151	0
Transfer of restricted cash to operating cash and cash equivalents as a result of sale	21,578	0
Acquisition of subsidiary interest from noncontrolling interest	20,630	0
Tenant improvements and capital expenditures payable	14,470	8,456
Capital lease asset	20,000	0
Reclass of development costs from other assets to real estate	47,519	0
Transfer to net assets held for sale	117,885	753,457
Transfer to liabilities related to net assets held for sale	94	461,891
Transfer of financing receivable to debt investment	0	19,675
Deferred leasing payable	6,176	13,086
Consolidation of real estate	0	1,316,591
Deconsolidation of subsidiary	27,435	0
Issuance of common stock to consolidated joint venture	10,000	0
Contribution to consolidated joint venture by noncontrolling interest	22,504	0
Receivable from sale of unconsolidated joint venture interests	15,129	0
Common Stock
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units	2,228	0
Common Stock | SL Green Operating Partnership
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units	2,228	0
Preferred Units
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units	211,601	27,565
Preferred Units | SL Green Operating Partnership
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units	$ 211,601	$ 27,565

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation SL Green Realty Corp., which is referred to as the Company or SL Green, a Maryland corporation, and SL Green Operating Partnership, L.P., which is referred to as SLGOP or the Operating Partnership, a Delaware limited partnership, were formed in June 1997 for the purpose of combining the commercial real estate business of S.L. Green Properties, Inc. and its affiliated partnerships and entities. The Operating Partnership received a contribution of interest in the real estate properties, as well as 95% of the economic interest in the management, leasing and construction companies which are referred to as the Service Corporation, a consolidated variable interest entity. All of the management, leasing and construction services that are provided to the properties that are wholly-owned by us and that are provided to certain joint ventures are conducted through SL Green Management LLC which is 100% owned by the Operating Partnership. The Company has qualified, and expects to qualify in the current fiscal year, as a real estate investment trust, or REIT, under the Internal Revenue Code of 1986, as amended, or the Code, and operates as a self-administered, self-managed REIT. A REIT is a legal entity that holds real estate interests and, through payments of dividends to stockholders, is permitted to minimize the payment of Federal income taxes at the corporate level. Unless the context requires otherwise, all references to "we," "our" and "us" means the Company and all entities owned or controlled by the Company, including the Operating Partnership. Substantially all of our assets are held by, and all of our operations are conducted through the Operating Partnership. The Company is the sole managing general partner of the Operating Partnership. As of September 30, 2015 , noncontrolling investors held, in the aggregate, a 3.74% limited partnership interest in the Operating Partnership. We refer to these interests as the noncontrolling interests in the Operating Partnership. See Note 11, "Noncontrolling Interests on the Company's Consolidated Financial Statements." Reckson Associates Realty Corp., or Reckson, and Reckson Operating Partnership, L.P., or ROP, are wholly-owned subsidiaries of the Operating Partnership. As of September 30, 2015 , we owned the following interests in commercial and residential properties in the New York Metropolitan area, primarily in midtown Manhattan. Our investments in the New York Metropolitan area also include investments in Brooklyn, Long Island, Westchester County, Connecticut and New Jersey, which are collectively known as the Suburban properties: Consolidated Unconsolidated Total Location Type Number of Properties Approximate Square Feet Number of Properties Approximate Square Feet Number of Properties Approximate Square Feet Weighted Average Occupancy (1) Commercial: Manhattan Office 26 20,700,091 6 3,328,496 32 24,028,587 94.5 % Retail 9 (3) 408,993 9 347,970 18 756,963 91.2 % Development/Redevelopment (2) 5 72,962 4 1,952,782 9 2,025,744 53.8 % Fee Interest 2 783,530 — — 2 783,530 100.0 % 42 21,965,576 19 5,629,248 61 27,594,824 91.5 % Suburban Office (2) 28 4,450,400 3 705,641 31 5,156,041 80.1 % Retail 1 52,000 — — 1 52,000 100.0 % Development/Redevelopment 1 1,000 1 — 2 1,000 100.0 % 30 4,503,400 4 705,641 34 5,209,041 80.3 % Total commercial properties 72 26,468,976 23 6,334,889 95 32,803,865 89.8 % Residential: Manhattan Residential 4 (3) 762,587 18 2,210,233 22 2,972,820 94.6 % Suburban Residential 1 66,611 — — 1 66,611 95.8 % Total residential properties 5 829,198 18 2,210,233 23 3,039,431 94.6 % Total portfolio 77 27,298,174 41 8,545,122 118 35,843,296 90.2 % ____________________________________________________________________ (1) The weighted average occupancy for commercial properties represents the total occupied square feet divided by total available rentable square feet. The weighted average occupancy for residential properties represents the total occupied units divided by total available units. (2) Includes two Manhattan redevelopment properties and two suburban office properties held for sale as of September 30, 2015. (3) As of September 30, 2015 , we owned a building that was comprised of approximately 270,132 square feet of retail space and approximately 222,855 square feet of residential space. For the purpose of this report, we have included the building in the retail properties count and have bifurcated the square footage into the retail and residential components. As of September 30, 2015 , we also managed an approximately 336,201 square foot office building owned by a third party and held debt and preferred equity investments with a book value of $1.5 billion . Partnership Agreement In accordance with the partnership agreement of the Operating Partnership, or the Operating Partnership Agreement, we allocate all distributions and profits and losses in proportion to the percentage of ownership interests of the respective partners. As the managing general partner of the Operating Partnership, we are required to take such reasonable efforts, as determined by us in our sole discretion, to cause the Operating Partnership to distribute sufficient amounts to enable the payment of sufficient dividends by us to minimize any Federal income or excise tax at the Company level. Under the Operating Partnership Agreement, each limited partner has the right to redeem units of limited partnership interests for cash, or if we so elect, shares of SL Green's common stock on a one-for- one basis. Basis of Quarterly Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for the fair presentation of the financial position of the Company and the Operating Partnership at September 30, 2015 and the results of operations for the periods presented have been included. The operating results for the period presented are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 . These financial statements should be read in conjunction with the financial statements and accompanying notes included in the Annual Report on Form 10-K for the year ended December 31, 2014 of the Company and the Operating Partnership. The consolidated balance sheets at December 31, 2014 have been derived from the audited financial statements as of that date but do not include all the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Principles of Consolidation The consolidated financial statements include our accounts and those of our subsidiaries, which are wholly-owned or controlled by us. Entities which we do not control through our voting interest and entities which are variable interest entities, but where we are not the primary beneficiary, are accounted for under the equity method or as debt and preferred equity investments. See Note 5, "Debt and Preferred Equity Investments" and Note 6, "Investments in Unconsolidated Joint Ventures." All significant intercompany balances and transactions have been eliminated. We consolidate a variable interest entity, or VIE, in which we are considered the primary beneficiary. The primary beneficiary is the entity that has (i) the power to direct the activities that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. Included in commercial real estate properties on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 are $198.6 million and $198.4 million , respectively, related to our consolidated VIEs. Included in mortgages and other loans payable on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 are $105.0 million and $106.5 million , respectively, related to our consolidated VIEs. As of September 30, 2015, assets held for sale and liabilities related to assets held for sale on the consolidated balance sheets did not include amounts related to consolidated VIEs. As of December 31, 2014, assets held for sale and liabilities related to assets held for sale on the consolidated balance sheets included $445.0 million of commercial real estate and $253.9 million of mortgage related to the consolidated VIEs. A noncontrolling interest in a consolidated subsidiary is defined as the portion of the equity (net assets) in a subsidiary not attributable, directly or indirectly, to us. Noncontrolling interests are required to be presented as a separate component of equity in the consolidated balance sheet and the presentation of net income is modified to present earnings and other comprehensive income attributed to controlling and noncontrolling interests. We assess the accounting treatment for each joint venture and debt and preferred equity investment. This assessment includes a review of each joint venture or limited liability company agreement to determine which party has what rights and whether those rights are protective or participating. For all VIEs, we review such agreements in order to determine which party has the power to direct the activities that most significantly impact the entity's economic performance. In situations where we and our partner approve, among other things, the annual budget, receive a detailed monthly reporting package, meet on a quarterly basis to review the results of the joint venture, review and approve the joint venture's tax return before filing, and approve all leases that cover more than a nominal amount of space relative to the total rentable space at each property, we do not consolidate the joint venture as we consider these to be substantive participation rights that result in shared power of the activities that most significantly impact the performance of the joint venture. Our joint venture agreements typically contain certain protective rights such as the requirement of partner approval to sell, finance or refinance the property and the payment of capital expenditures and operating expenditures outside of the approved budget or operating plan. Investment in Commercial Real Estate Properties On a periodic basis, we assess whether there are any indications that the value of our real estate properties may be other than temporarily impaired or that their carrying value may not be recoverable. A property's value is considered impaired if management's estimate of the aggregate future cash flows (undiscounted and without interest charges for consolidated properties) to be generated by the property is less than the carrying value of the property. To the extent impairment has occurred, the loss will be measured as the excess of the carrying amount of the property over the calculated fair value of the property. We also evaluate our real estate properties for potential impairment when a real estate property has been classified as held for sale. Real estate assets held for sale are valued at the lower of either their carrying value or fair value less costs to sell. During the three months ended September 30, 2015 , we recorded a $19.2 million charge in connection with the expected sale of two of our properties. This charge is included in depreciable real estate reserves in the consolidated statements of operations. Prior to the quarter ended September 30, 2015, we do not believe that there were any indicators of impairment at these two properties. See Note 4, "Properties Held for Sale and Property Dispositions." Except as noted above, we do not believe that there were any indicators of impairment at any of our consolidated properties at September 30, 2015 . We allocate the purchase price of real estate to land and building (inclusive of tenant improvements) and, if determined to be material, intangibles, such as the value of above- and below-market leases and origination costs associated with the in-place leases. We depreciate the amount allocated to building (inclusive of tenant improvements) over their estimated useful lives, which generally range from three to 40 years . We amortize the amount allocated to the above- and below-market leases over the remaining term of the associated lease, which generally range from one to 14 years, and record it as either an increase (in the case of below-market leases) or a decrease (in the case of above-market leases) to rental income. We amortize the amount allocated to the values associated with in-place leases over the expected term of the associated lease, which generally ranges from one to 14 years. If a tenant vacates its space prior to the contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related intangible will be written off. The tenant improvements and origination costs are amortized as an expense over the remaining life of the lease (or charged against earnings if the lease is terminated prior to its contractual expiration date). We assess fair value of the leases based on estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends, and market/economic conditions that may affect the property. To the extent acquired leases contain fixed rate renewal options that are below-market and determined to be material, we amortize such below-market lease value into rental income over the renewal period. We recognized $10.2 million , $32.9 million , $5.7 million and $18.2 million of rental revenue for the three and nine months ended September 30, 2015 and 2014, respectively, for the amortization of aggregate below-market leases in excess of above-market leases and a reduction in lease origination costs, resulting from the allocation of the purchase price of the applicable properties. We recognized as a reduction to interest expense the amortization of the above-market rate mortgages assumed of $0.6 million , $1.7 million , $1.3 million and $4.1 million for the three and nine months ended September 30, 2015 and 2014, respectively. The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Identified intangible assets (included in other assets): Gross amount $ 939,518 $ 664,297 Accumulated amortization (392,854 ) (383,236 ) Net (1) $ 546,664 $ 281,061 Identified intangible liabilities (included in deferred revenue): Gross amount $ 866,561 $ 655,755 Accumulated amortization (476,272 ) (483,948 ) Net (1) $ 390,289 $ 171,807 ____________________________________________________________________ (1) As of September 30, 2015, $0.2 million and $0.1 million of net intangible assets and net intangible liabilities, respectively, were reclassed to assets held for sale and liabilities related to assets held for sale. Fair Value Measurements See Note 17, "Fair Value Measurements." Investment in Marketable Securities We designate a security as held-to-maturity, available-for-sale, or trading at acquisition. As of September 30, 2015 , we do not have any securities designated as held-to-maturity or trading. We account for our available-for-sale securities at fair value pursuant to Accounting Standards Codification, or ASC, 820-10, with the net unrealized gains or losses reported as a component of accumulated other comprehensive income or loss. Any unrealized losses that are determined to be other-than-temporary are recognized in earnings up to their credit component. The cost of bonds and marketable securities sold is determined using the specific identification method. At September 30, 2015 and December 31, 2014 , we held the following marketable securities (in thousands): September 30, 2015 December 31, 2014 Equity marketable securities $ 4,115 $ 4,332 Mortgage-backed securities 42,317 35,097 Total marketable securities available-for-sale $ 46,432 $ 39,429 The cost basis of the commercial mortgage-backed securities was $39.7 million and $32.4 million at September 30, 2015 and December 31, 2014 , respectively. These securities mature at various times through 2049. During the nine months ended September 30, 2015 and 2014, we disposed of marketable securities for aggregate net proceeds of $0.4 million and $3.7 million , respectively. Investments in Unconsolidated Joint Ventures We assess our investments in unconsolidated joint ventures for recoverability, and if it is determined that a loss in value of the investment is other than temporary, we write down the investment to its fair value. We evaluate our equity investments for impairment based on the joint venture's projected discounted cash flows. We do not believe that the values of any of our equity investments were impaired at September 30, 2015 . We may originate loans for real estate acquisition, development and construction, where we expect to receive some of the residual profit from such projects. When the risk and rewards of these arrangements are essentially the same as an investor or joint venture partner, we account for these arrangements as real estate investments under the equity method of accounting for investments. Otherwise, we account for these arrangements consistent with our loan accounting for our debt and preferred equity investments. Revenue Recognition Rental revenue is recognized on a straight-line basis over the term of the lease. Rental revenue recognition commences when the tenant takes possession or controls the physical use of the leased space. In order for the tenant to take possession, the leased space must be substantially ready for its intended use. To determine whether the leased space is substantially ready for its intended use, management evaluates whether we are or the tenant is the owner of tenant improvements for accounting purposes. When management concludes that we are the owner of tenant improvements, rental revenue recognition begins when the tenant takes possession of the finished space, which is when such tenant improvements are substantially complete. In certain instances, when management concludes that we are not the owner (the tenant is the owner) of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space. When management concludes that we are the owner of tenant improvements for accounting purposes, we record amounts funded to construct the tenant improvements as a capital asset. For these tenant improvements, we record amounts reimbursed by tenants as a reduction of the capital asset. When management concludes that the tenant is the owner of tenant improvements for accounting purposes, we record our contribution towards those improvements as a lease incentive, which is included in deferred costs, net on our consolidated balance sheets and amortized as a reduction to rental revenue on a straight-line basis over the term of the lease. The excess of rents recognized over amounts contractually due pursuant to the underlying leases are included in deferred rents receivable on the consolidated balance sheets. We establish, on a current basis, an allowance for future potential tenant credit losses, which may occur against this account. The balance reflected on the consolidated balance sheets is net of such allowance. In addition to base rent, our tenants also generally will pay their pro rata share of increases in real estate taxes and operating expenses for the building over a base year. In some leases, in lieu of paying additional rent based upon increases in building operating expenses, the tenant will pay additional rent based upon increases in the wage rate paid to porters over the porters' wage rate in effect during a base year or increases in the consumer price index over the index value in effect during a base year. In addition, many of our leases contain fixed percentage increases over the base rent to cover escalations. Electricity is most often supplied by the landlord either on a sub-metered basis, or rent inclusion basis (i.e., a fixed fee is included in the rent for electricity, which amount may increase based upon increases in electricity rates or increases in electrical usage by the tenant). Base building services other than electricity (such as heat, air conditioning and freight elevator service during business hours, and base building cleaning) are typically provided at no additional cost, with the tenant paying additional rent only for services which exceed base building services or for services which are provided outside normal business hours. These escalations are based on actual expenses incurred in the prior calendar year. If the expenses in the current year are different from those in the prior year, then during the current year, the escalations will be adjusted to reflect the actual expenses for the current year. We record a gain on sale of real estate when title is conveyed to the buyer, subject to the buyer's financial commitment being sufficient to provide economic substance to the sale and we have no substantial economic involvement with the buyer. Interest income on debt and preferred equity investments is accrued based on the outstanding principal amount and contractual terms of the instruments and when, in the opinion of management, it is deemed collectible. Several of the debt and preferred equity investments provide for accrual of interest at specified rates, which differ from current payment terms. Interest is recognized on such loans at the accrual rate subject to management's determination that accrued interest is ultimately collectible, based on the underlying collateral and operations of the borrower. If management cannot make this determination, interest income above the current pay rate is recognized only upon actual receipt. Deferred origination fees, original issue discounts and loan origination costs, if any, are recognized as a reduction to the interest income over the terms of the related investments using the effective interest method. Fees received in connection with loan commitments are also deferred until the loan is funded and are then recognized over the term of the loan as an adjustment to yield. Discounts or premiums associated with the purchase of loans are amortized or accreted into interest income as a yield adjustment on the effective interest method based on expected cashflows through the expected maturity date of the related investment. If we purchase a debt or preferred equity investment at a discount, intend to hold it until maturity and expect to recover the full value of the investment, we accrete the discount into income as an adjustment to yield over the term of the investment. If we purchase a debt or preferred equity investment at a discount with the intention of foreclosing on the collateral, we do not accrete the discount. For debt investments acquired at a discount for credit quality, the difference between contractual cash flows and expected cash flows at acquisition is not accreted. Anticipated exit fees, the collection of which is expected, are also recognized over the term of the loan as an adjustment to yield. Debt and preferred equity investments are placed on a non-accrual status at the earlier of the date at which payments become 90 days past due or when, in the opinion of management, a full recovery of interest income becomes doubtful. Interest income recognition on any non-accrual debt or preferred equity investment is resumed when such non-accrual debt or preferred equity investment becomes contractually current and performance is demonstrated to be resumed. Interest is recorded as income on impaired loans only to the extent cash is received. We may syndicate a portion of the loans that we originate or sell these loans individually. When a transaction meets the criteria of sale accounting, we derecognize the loan sold and recognize gain or loss based on the difference between the sales price and the carrying value of the loan sold. Any related unamortized deferred origination fees, original issue discounts, loan origination costs, discounts or premiums at the time of sale are recognized as an adjustment to the gain or loss on sale, which is included in investment income on the consolidated statement of income. Any fees received at the time of sale or syndication are recognized as part of investment income. Asset management fees are recognized on a straight-line basis over the term of the asset management agreement. Reserve for Possible Credit Losses The expense for possible credit losses in connection with debt and preferred equity investments is the charge to earnings to increase the allowance for possible credit losses to the level that we estimate to be adequate, based on Level 3 data, considering delinquencies, loss experience and collateral quality. Other factors considered relate to geographic trends and product diversification, the size of the portfolio and current economic conditions. Based upon these factors, we establish the provision for possible credit losses on each individual investment. When it is probable that we will be unable to collect all amounts contractually due, the investment is considered impaired. Where impairment is indicated on an investment that is held to maturity, a valuation allowance is measured based upon the excess of the recorded investment amount over the net fair value of the collateral. Any deficiency between the carrying amount of an asset and the calculated value of the collateral is charged to expense. We continue to assess or adjust our estimates based on circumstances of a loan and the underlying collateral. If the additional information obtained reflects increased recovery of our investment, we will adjust our reserves accordingly. There were no loan reserves recorded during three and nine months ended September 30, 2015 and 2014 . Debt and preferred equity investments held for sale are carried at the lower of cost or fair market value using available market information obtained through consultation with dealers or other originators of such investments as well as discounted cash flow models based on Level 3 data pursuant to ASC 820-10. As circumstances change, management may conclude not to sell an investment designated as held for sale. In such situations, the investment will be reclassified at its net carrying value to debt and preferred equity investments held to maturity. For these reclassified investments, the difference between the current carrying value and the expected cash to be collected at maturity will be accreted into income over the remaining term of the investment. Income Taxes SL Green is taxed as a REIT under Section 856(c) of the Code. As a REIT, SL Green generally is not subject to Federal income tax. To maintain its qualification as a REIT, SL Green must distribute at least 90% of its REIT taxable income to its stockholders and meet certain other requirements. If SL Green fails to qualify as a REIT in any taxable year, SL Green will be subject to Federal income tax on SL Green's taxable income at regular corporate rates. SL Green may also be subject to certain state, local and franchise taxes. Under certain circumstances, Federal income and excise taxes may be due on SL Green's undistributed taxable income. The Operating Partnership is a partnership and, as a result, all income and losses of the partnership are allocated to the partners for inclusion in their respective income tax returns. The only provision for income taxes included in the consolidated statements of operations relates to the Operating Partnership’s consolidated taxable REIT subsidiaries. The Operating Partnership may also be subject to certain state, local and franchise taxes. Pursuant to amendments to the Code that became effective January 1, 2001, we have elected, and may elect in the future, to treat certain of our existing or newly created corporate subsidiaries as taxable REIT subsidiaries, or TRSs. In general, TRSs may perform non-customary services for the tenants of the Company, hold assets that we cannot hold directly and generally may engage in any real estate or non-real estate related business. The TRSs generate income, resulting in Federal and state income tax liability for these entities. During the three and nine months ended September 30, 2015 and 2014 , we recorded Federal, state and local tax provisions of $1.1 million , $2.5 million , $1.6 million and $6.6 million , respectively. We follow a two-step approach for evaluating uncertain tax positions. Recognition (step one) occurs when an enterprise concludes that a tax position, based solely on its technical merits, is more-likely-than-not to be sustained upon examination. Measurement (step two) determines the amount of benefit that is more-likely-than-not to be realized upon settlement. Derecognition of a tax position that was previously recognized would occur when a company subsequently determines that a tax position no longer meets the more-likely-than-not threshold of being sustained. The use of a valuation allowance as a substitute for derecognition of tax positions is prohibited. Stock-Based Employee Compensation Plans We have a stock-based employee compensation plan, described more fully in Note 14, "Share-based Compensation." The Company's stock options are recorded at fair value at the time of issuance. Fair value of the stock options is determined using the Black-Scholes option pricing model. The Black-Scholes model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of highly subjective assumptions including the expected stock price volatility. Because our plan has characteristics significantly different from those of traded options and because changes in the subjective input assumptions can materially affect the fair value estimate, in our opinion, the existing models do not necessarily provide a reliable single measure of the fair value of the employee stock options. Compensation cost for stock options, if any, is recognized over the vesting period of the award. Our policy is to grant options with an exercise price equal to the quoted closing market price of the Company's common stock on the grant date. Awards of stock or restricted stock are expensed as compensation over the benefit period based on the fair value of the stock on the grant date. For share-based awards with a performance or market measure, we recognize compensation cost over the requisite service period, using the accelerated attribution expense method. The requisite service period begins on the date the compensation committee of SL Green's board of directors authorizes the award, adopts any relevant performance measures and communicates the award to the employees. For programs with awards that vest based on the achievement of a performance condition or market condition, we determine whether it is probable that the performance condition will be met, and estimate compensation cost based on the fair value of the award at the applicable reporting date estimated using a binomial model or market quotes. For share-based awards for which there is no pre-established performance measure, we recognize compensation cost over the service vesting period, which represents the requisite service period, on a straight-line basis. In accordance with the provisions of our share-based incentive compensation plans, we accept the return of shares of the Company's common stock, at the current quoted market price, from certain key employees to satisfy minimum statutory tax-withholding requirements related to shares that vested during the period. Awards can also be made in the form of a separate series of units of limited partnership interest in the Operating Partnership called long-term incentive plan units, or LTIP units. LTIP units, which can be granted either as free-standing awards or in tandem with other awards under our stock incentive plan, are valued by reference to the value of the Company's common stock at the time of grant, and are subject to such conditions and restrictions as the compensation committee of the Company's board of directors may determine, including continued employment or service, computation of financial metrics and/or achievement of pre-established performance goals and objectives. Earnings per Share of the Company The Company presents both basic and diluted earnings per share, or EPS. Basic EPS excludes dilution and is computed by dividing net income or loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Basic EPS includes participating securities, consisting of unvested restricted stock that receive nonforfeitable dividends similar to shares of common stock. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, where such exercise or conversion would result in a lower EPS amount. Diluted EPS also includes units of limited partnership interest. The dilutive effect of stock options is reflected in the weighted average diluted outstanding shares calculation by application of the treasury stock method. There is no dilutive effect for the exchangeable senior notes as the conversion premium will be paid in cash. Earnings per Unit of the Operating Partnership The Operating Partnership presents both basic and diluted earnings per unit, or EPU. Basic EPU excludes dilution and is computed by dividing net income or loss attributable to common unitholders by the weighted average number of common units outstanding during the period. Basic EPU includes participating securities, consisting of unvested restricted units that receive nonforfeitable dividends similar to shares of common units. Diluted EPU reflects the potential dilution that could occur if securities or other contracts to issue common units were exercised or converted into common units, where such exercise or conversion would result in a lower EPU amount. The dilutive effect of unit options is reflected in the weighted average diluted outstanding units calculation by application of the treasury stock method. There is no dilutive effect for the exchangeable senior notes as the conversion premium will be paid in cash. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash investments, debt and preferred equity investments and accounts receivable. We place our cash investments in excess of insured amounts with high quality financial institutions. The collateral securing our debt and preferred equity investments is located in New York City. See Note 5, "Debt and Preferred Equity Investments." We perform ongoing credit evaluations of our tenants and require most tenants to provide security deposits or letters of credit. Though these security deposits and letters of credit are insufficient to meet the total value of a tenant's lease obligation, they are a measure of good faith and a source of funds to offset the economic costs associated with lost rent and the costs associated with re-tenanting a space. Although the properties in our real estate portfolio are primarily located in Manhattan, we also have properties located in Brooklyn, Long Island, Westchester County, Connecticut and New Jersey. The tenants located in our buildings operate in various industries. Other than three tenants who account for 9.8% , 9.2% and 6.3% of our share of annualized cash rent, respectively, no other tenant in our portfolio accounted for more than 5.0% of our share of annualized cash rent, including our share of joint venture annualized rent, at September 30, 2015 . For the three months ended September 30, 2015 , 9.7% , 8.8% , 7.3% , 7.0% , 6.7% , 5.7% , and 5.4% of our annualized cash rent for consolidated properties was attributable to 1515 Broadway, 388 and 390 Greenwich Street, 919 Third Ave, 1185 Avenue of the Americas, 11 Madison Ave, 420 Lexington Ave, and 1 Madison Ave respectively. Annualized cash rent for all other consolidated properties was below 5.0% . Reclassification Certain prior year balances have been reclassified to conform to our current year presentation primarily in order to eliminate discontinued operations from income from continuing operations. Accounting Standards Updates In September 2015, the Financial Accounting Standards Board, or FASB, issued final guidance to simplify the measurement-period adjustments in business combinations (Accounting Standards Update, or ASU, No. 2015-62). The guidance eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, acquirers must recognize measurement-period adjustments in the period in which they determine the amounts, including the effect on earnings of any amounts they would have recorded in previously periods if the accounting had been completed at the acquisition date. The guidance is effective for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the guidance is permitted. The Company adopted the guidance during the third quarter of 2015. In April 2015, the FASB issued final guidance to simplify the presentation of debt issuance costs by requiring debt issuance costs to be presented as a deduction from the corresponding debt liability (ASU No. 2015-03). The guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The guidance is effective for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the guidance is permitted. Upon adoption, an entity must apply the new guidance retrospectively for all prior periods presented in the financial statements. The Company expects to adopt the guidance effective January 1, 2016 and the guidance is not anticipated to have a material impact on our consolidated financial statements. In February 2015, the FASB issued new guidance that amends the current consolidation guidance, including introducing a separate consolidation analysis specific to limited partnerships and other similar entities (ASU No. 2015-02). Under this analysis, limited partnerships and other similar entities will be considered a VIE unless the limited partners hold substantive kick-out rights or participating rights. The guidance is effective for ann

Property Acquisitions

Property Acquisitions	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Property Acquisitions	Property Acquisitions 2015 Acquisitions During the nine months ended September 30, 2015 , the properties listed below were acquired from third parties. The following summarizes our preliminary allocation of the purchase price of the assets acquired and liabilities assumed upon the closing of these acquisitions (in thousands): 187 Broadway and 5 & 7 Dey Street (1)(2) 11 Madison Avenue (1)(3) 110 Greene Street (1)(4) Upper East Side Residential (1)(5) 1640 Flatbush Avenue (1) Acquisition Date August 2015 August 2015 July 2015 June 2015 March 2015 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Property Type Residential/Retail Office Office Residential/Retail Retail Purchase Price Allocation: Land $ 22,101 $ 849,926 $ 89,250 $ 17,500 $ 6,120 Building and building leasehold 41,045 1,579,118 165,750 32,500 680 Above-market lease value — — — — — Acquired in-place leases — — — — — Other assets, net of other liabilities — — — — — Assets acquired 63,146 2,429,044 255,000 50,000 6,800 Mark-to-market assumed debt — — — — — Below-market lease value — — — — — Derivatives — — — — — Liabilities assumed — — — — — Purchase price $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Net consideration funded by us at closing, excluding consideration financed by debt $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Equity and/or debt investment held $ — $ — $ — $ — $ — Debt assumed $ — $ — $ — $ — $ — ____________________________________________________________________ (1) We are currently in the process of analyzing the purchase price allocation and, as such, we have not allocated any value to intangible assets such as above- and below-market lease or in-place leases. (2) We acquired this property for consideration that included the issuance of $10.0 million and $26.9 million aggregate liquidation preferences of Series R and S Preferred Units, respectively, of limited partnership interest of the Operating Partnership and cash. (3) In August 2015, we acquired this property from a partnership of the Sapir Organization and CIM Group, with whom we have no other relationship. (4) We acquired a 90.0% controlling interest in this property for consideration that included the issuance of $5.0 million and $6.7 million aggregate liquidation preferences of Series P and Q Preferred Units, respectively, of limited partnership interest of the Operating Partnership and cash. (5) We, along with our joint venture partner, acquired this property for consideration that included the issuance of $13.8 million aggregate liquidation preference of Series N Preferred Units of limited partnership interest of the Operating Partnership and cash. We hold a 95.1% controlling interest in this joint venture. Pro Forma The following table summarizes, on an unaudited pro forma basis, the results of operations of 11 Madison Avenue, which are included in the consolidated statements of operations, and our consolidated results of operations for the three and nine months ended September 30, 2015 and 2014 as though the acquisition of 11 Madison Avenue was completed on January 1, 2014. The supplemental pro forma data is not necessarily indicative of what the actual results of operations would have been assuming the transactions had been completed as set forth above, nor do they purport to represent our results of operations for future periods. Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2015 2014 2015 2014 Actual revenues since acquisition $ 9,051 $ 9,051 Actual net income since acquisition (4,202 ) (4,202 ) Pro forma revenues 432,822 397,684 1,255,507 1,146,697 Pro forma income from continuing operations 25,299 31,197 26,645 350,125 Pro forma basic earnings per share $ 0.18 $ 0.59 $ 0.11 $ 6.39 Pro forma diluted earnings per share $ 0.18 $ 0.59 $ 0.11 $ 6.36 Pro forma basic earnings per unit $ 0.18 $ 0.59 $ 0.11 $ 6.39 Pro forma diluted earnings per unit $ 0.18 $ 0.59 $ 0.11 $ 6.36 ______________________________________________________________________ (1) The pro forma income from continuing operations for the three and nine months ended September 30, 2015 and 2014 includes the effect of the incremental borrowings, including a $1.4 billion , 10 -year, interest only, fixed rate mortgage financing carrying a per annum stated interest rate of 3.838% to complete the acquisition and the preliminary allocation of purchase price. In addition, the pro forma net income for the nine months ended September 30, 2014 was adjusted to include the sale of real estate assets for properties that have closed either subsequent to June 30, 2015 or we are currently under contract to sell, as if the sales were completed on January 1, 2014. The pro forma net income for the three and nine months ended September 30, 2015 excludes these sales. 2014 Acquisitions During the nine months ended September 30, 2015 , we finalized the purchase price allocations based on third party appraisal and additional facts and circumstances that existed at the acquisition dates for the following 2014 acquisitions (in thousands): 102 Greene Street (1) 635 Madison Avenue (1) 719 Seventh Avenue (1)(2) 115 Spring Street (1) 388-390 Greenwich Street (1)(3) Acquisition Date October 2014 September 2014 July 2014 July 2014 May 2014 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Property Type Retail Land Development Retail Office Purchase Price Allocation: Land $ 8,215 $ 205,632 $ 41,850 $ 11,078 $ 516,292 Building and building leasehold 26,717 15,805 — 44,799 964,434 Above-market lease value — — — — — Acquired in-place leases 1,015 17,345 — 2,037 302,430 Other assets, net of other liabilities 3 — — — 6,495 Assets acquired 35,950 238,782 41,850 57,914 1,789,651 Mark-to-market assumed debt — — — — — Below-market lease value 3,701 85,036 — 4,789 186,782 Derivatives — — — — 18,001 Liabilities assumed 3,701 85,036 — 4,789 204,783 Purchase price $ 32,249 $ 153,746 $ 41,850 $ 53,125 $ 1,584,868 Net consideration funded by us at closing, excluding consideration financed by debt $ 32,249 $ 153,746 $ 41,850 $ 53,125 $ 208,614 Equity and/or debt investment held $ — $ — $ — $ — $ 148,025 Debt assumed $ — $ — $ — $ — $ 1,162,379 ____________________________________________________________________ (1) Based on our preliminary analysis of the purchase price, we had allocated $11.3 million and $21.0 million to land and building, respectively, at 102 Greene Street, $153.7 million to land at 635 Madison Avenue, $14.4 million and $26.7 million to land and building, respectively, at 719 Seventh Avenue, $15.9 million and $37.2 million to land and building, respectively, at 115 Spring Street and $558.7 million and $1.0 billion to land and building, respectively, at 388-390 Greenwich. The impact to our consolidated statement of income for the nine months ended September 30, 2015 was $7.6 million in rental revenue for the amortization of aggregate below-market leases and $10.3 million of depreciation expense. (2) We, along with our joint venture partner, acquired this property for consideration that included the issuance of $14.1 million aggregate liquidation preference of Series L Preferred Units of limited partnership interest of the Operating Partnership and $9.5 million aggregate liquidation preference of Series K Preferred Units of limited partnership interest of the Operating Partnership. We hold a 75.0% controlling interest in this joint venture. (3) In May 2014, we acquired Ivanhoe Cambridge, Inc.'s 49.65% economic interest in this property, thereby consolidating full ownership of the property. The transaction valued the consolidated interests at $1.585 billion . Simultaneous with the closing, we refinanced the previous mortgage with a $1.45 billion mortgage. We also assumed the existing derivative instruments, which swapped $504.0 million of the mortgage to fixed rate (in October 2014, we entered into multiple swap agreements to hedge our interest rate exposure on an additional $500.0 million portion of this mortgage. See Note 8, "Mortgages and Other Loans Payable" for further details). We recognized a purchase price fair value adjustment of $71.4 million upon closing of this transaction. This property, which we initially acquired in December 2007, was previously accounted for as an investment in unconsolidated joint ventures. For business combinations achieved in stages, the acquisition-date fair value of our equity interest in a property immediately before the acquisition date is determined based on estimated cash flow projections that utilize available market information and discount and capitalization rates that we deem appropriate. Estimates of future cash flows are based on a number of factors including historical operating results, known and anticipated trends, and market and economic conditions. The acquisition-date fair value of the equity interest in 388-390 Greenwich Street immediately before the acquisition date as well as the purchase price fair value, as determined in accordance with the methodology set out in the prior sentence, is as follows (in thousands): 388-390 Greenwich Street Contract purchase price $ 1,585,000 Net consideration funded by us at closing, excluding consideration financed by debt (208,614 ) Debt assumed (1,162,379 ) Fair value of retained equity interest 214,007 Equity and/or debt investment held (148,025 ) Other (1) 5,464 Purchase price fair value adjustment $ 71,446 ___________________________________________________________________ (1) Includes the acceleration of a deferred leasing commission from the joint venture to the Company.

Properties Held for Sale and Pr

Properties Held for Sale and Property Dispositions	9 Months Ended
	Sep. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Properties Held for Sale and Property Dispositions	Properties Held for Sale and Property Dispositions Properties Held for Sale During the third quarter of 2015, we entered into separate agreements to sell 570-574 Fifth Avenue for $125.4 million and 140-150 Grand Street in White Plains, New York for $32.0 million . During the quarter, we recorded a $19.2 million charge in connection with the expected sale of 140-150 Grand Street. These charges are included in depreciable real estate reserves in the consolidated statements of operations. See Note 2, "Significant Account Policies - Investments in Commercial Real Estate Properties" for further discussion. Property Disposition The following table summarizes the properties sold during the nine months ended September 30, 2015 : Property Disposition Date Property Type Approximate Usable Square Feet Sales Price (1) (in millions) Gain on Sale (2) (in millions) 180 Maiden Lane January 2015 Office 1,090,000 $ 470.0 $ 17.0 131-137 Spring Street (3) August 2015 Office 68,342 277.8 101.1 120 West 45th Street September 2015 Office 440,000 365.0 58.6 ____________________________________________________________________ (1) Sales price represents the actual sales price for a property or the gross asset valuation for interests in a property. (2) The gain on sale for 180 Maiden Lane, 131-137 Spring Street, and 120 West 45th Street are net of employee compensation awards accrued in connection with the realization of these investment gains as a bonus to certain employees that were instrumental in realizing the gain on sale. Additionally, amounts do not include adjustments for expenses recorded in subsequent periods. (3) We sold an 80% interest in 131-137 Spring Street and have subsequently accounted for our interest in the properties as an investment in unconsolidated joint ventures. See Note 6, "Investments in Unconsolidated Joint Ventures." Discontinued Operations The Company adopted ASU 2014-08 effective January 1, 2015. As a result, the Company classified 570-574 Fifth Avenue and 140-150 Grand Street in White Plains, New York as held for sale as of September 30, 2015, and 131-137 Spring Street and 120 West 45th Street as of June 30, 2015 and included the results of operations in continuing operations for all periods presented. Discontinued operations included the results of operations of real estate assets sold or held for sale prior to January 1, 2015. This included 180 Maiden Lane, which was held for sale at December 31, 2014 and sold in January 2015, and 2 Herald Square, 985-987 Third Avenue and 673 First Avenue, which were sold during 2014. The following table summarizes net income from discontinued operations for the three and nine months ended September 30, 2015 and 2014 , respectively (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenues Rental revenue $ — $ 9,504 $ 236 $ 44,676 Escalation and reimbursement revenues — (194 ) (127 ) 4,413 Other income — — — 21 Total revenues — 9,310 109 49,110 Operating expenses — 773 (631 ) 7,101 Real estate taxes — 787 250 6,618 Ground rent — — — 3,001 Transaction related costs — 115 (49 ) 155 Interest expense, net of interest income — 2,874 109 10,983 Amortization of deferred financing costs — 48 3 369 Depreciation and amortization — 678 — 5,434 Total expenses — 5,275 (318 ) 33,661 Net income from discontinued operations $ — $ 4,035 $ 427 $ 15,449

Debt and Preferred Equity Inves

Debt and Preferred Equity Investments	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Debt and Preferred Equity Investments	Debt and Preferred Equity Investments During the nine months ended September 30, 2015 and 2014 , our debt and preferred equity investments, net of discounts and deferred origination fees, increased $464.9 million and $476.6 million , respectively, due to originations, purchases, advances under future funding obligations, discount amortization, and paid-in-kind interest, net of premium amortization. We recorded repayments, participations and sales of $372.1 million and $348.5 million during the nine months ended September 30, 2015 and 2014 , respectively, which offset the increases in debt and preferred equity investments. Debt Investments As of September 30, 2015 and December 31, 2014, we held the following debt investments with an aggregate weighted average current yield of 10.32% at September 30, 2015 (in thousands): Loan Type September 30, 2015 Future Funding Obligations September 30, 2015 Senior Financing September 30, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Fixed Rate Investments: Jr. Mortgage Participation $ — $ 205,000 $ 72,541 $ 70,688 February 2016 Jr. Mortgage Participation/Mezzanine Loan (2)(3) — — 23,371 45,611 May 2016 Jr. Mortgage Participation — 133,000 49,000 49,000 June 2016 Mezzanine Loan — 165,000 72,031 71,656 November 2016 Jr. Mortgage Participation/Mezzanine Loan — 1,109,000 102,709 98,934 March 2017 Mezzanine Loan (3) — — 66,075 65,770 March 2017 Mezzanine Loan (4) 155 502,100 40,938 24,608 June 2017 Mezzanine Loan — 539,000 49,666 49,629 July 2018 Mortgage Loan (5) — — 26,249 26,209 February 2019 Mortgage Loan — — 545 637 August 2019 Loan Type September 30, 2015 Future Funding Obligations September 30, 2015 Senior Financing September 30, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Mezzanine Loan — 15,000 3,500 3,500 September 2021 Mezzanine Loan (6) — 90,000 19,934 19,930 November 2023 Mezzanine Loan — 95,000 30,000 30,000 January 2025 Mezzanine Loan (7) — — — 14,068 Jr. Mortgage Participation (8) — — — 11,934 Total fixed rate $ 155 $ 2,853,100 $ 556,559 $ 582,174 Floating Rate Investments: Mezzanine Loan — 775,000 74,349 73,402 March 2016 Mortgage/Mezzanine Loan 14,981 — 81,730 — April 2016 Mezzanine Loan (9) — 160,000 22,612 22,573 June 2016 Jr. Mortgage Participation — 30,000 15,000 — July 2016 Mezzanine Loan — 115,000 24,914 24,910 July 2016 Mezzanine Loan (10) — 110,000 50,000 49,614 September 2016 Mezzanine Loan — 360,000 99,398 99,023 November 2016 Mezzanine Loan 9,726 304,610 64,430 — November 2016 Mezzanine Loan (11) 12,885 127,824 48,226 42,750 December 2016 Mezzanine Loan 461 38,687 13,539 11,835 December 2016 Mortgage/Mezzanine Loan (12) 66,314 — 124,789 — January 2017 Mezzanine Loan 1,851 118,718 27,956 20,651 January 2017 Jr. Mortgage Participation/Mezzanine Loan 1,508 117,460 40,034 38,524 July 2017 Mortgage/Mezzanine Loan — — 22,858 22,803 July 2017 Mortgage/Mezzanine Loan — — 16,887 16,848 September 2017 Mezzanine Loan — 60,000 14,892 14,859 November 2017 Mortgage/Mezzanine Loan (13) 795 — 14,917 14,845 December 2017 Jr. Mortgage Participation — 40,000 19,830 — April 2018 Mezzanine Loan — 350,000 34,698 — April 2018 Jr. Mortgage Participation/Mezzanine Loan — 55,000 20,516 20,533 July 2018 Mortgage/Mezzanine Loan 1,500 — 31,185 — August 2018 Mortgage/Mezzanine Loan — — 18,316 18,083 February 2019 Mezzanine Loan — 38,000 21,835 21,807 March 2019 Mezzanine Loan (14) — — — 33,726 Mezzanine Loan (14) — — — 37,322 Mortgage/Mezzanine Loan (15) — — — 109,527 Total floating rate $ 110,021 $ 2,800,299 $ 902,911 $ 693,635 Total $ 110,176 $ 5,653,399 $ 1,459,470 $ 1,275,809 ____________________________________________________________________ (1) Carrying value is net of discounts, premiums, original issue discounts and deferred origination fees. (2) The $22.9 million junior mortgage participation, which matures in February 2016, was sold in July 2015. (3) These loans are collateralized by defeasance securities. (4) Carrying value is net of $41.3 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (5) In September 2014, we acquired a $26.4 million mortgage loan at a $0.2 million discount and a $5.7 million junior mortgage participation at a $5.7 million discount. The junior mortgage participation was a nonperforming loan at acquisition and is currently on non-accrual status. (6) Carrying value is net of $5.0 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (7) This loan was repaid in February 2015. (8) This loan was repaid in March 2015. (9) Carrying value is net of $7.4 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (10) In August 2015, the maturity date was extended to September 2016. (11) In February 2015, the maturity date was extended to December 2016. (12) Carrying value is net of $25.0 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (13) Carrying value is net of $5.1 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (14) These loans were repaid in April 2015. (15) This loan was repaid in August 2015. Preferred Equity Investments As of September 30, 2015 and December 31, 2014 , we held the following preferred equity investments with an aggregate weighted average current yield of 7.77% at September 30, 2015 (in thousands): Type September 30, 2015 Future Funding Obligations September 30, 2015 Senior Financing September 30, 2015 Carrying Value (1) December 31, 2014 (1) Initial Mandatory Redemption Preferred equity (2) $ — $ 70,000 $ 9,964 $ 9,954 March 2018 Preferred equity 5,580 60,387 32,185 — November 2018 Preferred equity (3) — — — 123,041 $ 5,580 $ 130,387 $ 42,149 $ 132,995 ____________________________________________________________________ (1) Carrying value is net of deferred origination fees. (2) In March 2015, the redemption date was extended to March 2018. (3) This investment was redeemed in July 2015. At September 30, 2015 and December 31, 2014, all debt and preferred equity investments were performing in accordance with the terms of the relevant investments, with the exception of a junior mortgage participation acquired in September 2014, which has a carrying value of zero. We have determined that we have one portfolio segment of financing receivables at September 30, 2015 and December 31, 2014 comprising commercial real estate which is primarily recorded in debt and preferred equity investments. Included in other assets is an additional amount of financing receivables totaling $115.5 million and $133.5 million at September 30, 2015 and December 31, 2014 , respectively. No financing receivables were 90 days past due at September 30, 2015 .

Investments in Unconsolidated J

Investments in Unconsolidated Joint Ventures	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures We have investments in several real estate joint ventures with various partners. As of September 30, 2015 and December 31, 2014 , 650 Fifth Avenue, 33 Beekman, and 3 Columbus Circle were VIEs in which we are not the primary beneficiary. Our net equity investment in these VIEs was $100.2 million and $146.2 million at September 30, 2015 and December 31, 2014 , respectively. All other investments below are voting interest entities. As we do not control the joint ventures listed below, we account for them under the equity method of accounting. The table below provides general information on each of our joint ventures as of September 30, 2015 : Property Partner Ownership Interest Economic Interest Approximate Square Feet Acquisition Date Acquisition Price (1) (in thousands) 100 Park Avenue Prudential Real Estate Investors 49.90% 49.90% 834,000 January 2000 $ 95,800 717 Fifth Avenue Jeff Sutton/Private Investor 10.92% 10.92% 119,500 September 2006 251,900 800 Third Avenue (2) Private Investors 60.52% 60.52% 526,000 December 2006 285,000 1745 Broadway Ivanhoe Cambridge, Inc. 56.88% 56.88% 674,000 April 2007 520,000 Jericho Plaza Onyx Equities/Credit Suisse 20.26% 20.26% 640,000 April 2007 210,000 600 Lexington Avenue Canadian Pension Plan Investment Board 55.00% 55.00% 303,515 May 2010 193,000 11 West 34th Street Private Investor/ Jeff Sutton 30.00% 30.00% 17,150 December 2010 10,800 7 Renaissance Louis Cappelli 50.00% 50.00% 65,641 December 2010 4,000 3 Columbus Circle (3) The Moinian Group 48.90% 48.90% 741,500 January 2011 500,000 280 Park Avenue Vornado Realty Trust 50.00% 50.00% 1,219,158 March 2011 400,000 1552-1560 Broadway (4) Jeff Sutton 50.00% 50.00% 35,897 August 2011 136,550 724 Fifth Avenue Jeff Sutton 50.00% 50.00% 65,040 January 2012 223,000 10 East 53rd Street Canadian Pension Plan Investment Board 55.00% 55.00% 354,300 February 2012 252,500 33 Beekman (5) Harel Insurance and Finance/TNG 33 LLC 45.90% 45.90% 163,500 August 2012 31,000 521 Fifth Avenue Plaza Global Real Estate Partners LP 50.50% 50.50% 460,000 November 2012 315,000 21 East 66th Street (6) Private Investors 32.28% 32.28% 16,736 December 2012 75,000 650 Fifth Avenue (7) Jeff Sutton 50.00% 50.00% 32,324 November 2013 — 121 Greene Street Jeff Sutton 50.00% 50.00% 7,131 September 2014 27,400 175-225 Third Street Brooklyn, New York KCLW 3rd Street LLC/LIVWRK LLC 95.00% 95.00% — October 2014 74,600 55 West 46th Street Prudential Real Estate Investors 25.00% 25.00% 347,000 November 2014 295,000 Stonehenge Portfolio (8) Various Various Various 2,046,733 February 2015 36,668 131-137 Spring Street (9) Invesco Real Estate 20.00% 20.00% 68,342 August 2015 277,750 ____________________________________________________________________ (1) Acquisition price represents the actual or implied gross purchase price for the joint venture, which is not adjusted for subsequent acquisitions of additional interest. (2) In March 2015, we acquired an additional 17.56% interest in this joint venture for $67.5 million . (3) As a result of the sale of a condominium interest in September 2012, Young & Rubicam, Inc., or Y&R, owns floors three through eight at the property. Because the joint venture has an option to repurchase these floors, the gain associated with this sale was deferred. (4) The purchase price represents only the purchase of the 1552 Broadway interest which comprised approximately 13,045 square feet. The joint venture also owns a long-term leasehold interest in the retail space and certain other spaces at 1560 Broadway, which is adjacent to 1552 Broadway. (5) The redevelopment project was substantially complete during the second quarter of 2015 and was conveyed to Pace University during the third quarter of 2015. In October 2015, we entered into an agreement to sell the property for $196.0 million . The transaction is expected to be completed in the first half of 2016, subject to customary closing conditions. (6) We hold a 32.28% interest in three retail and two residential units at the property and a 16.14% interest in three residential units at the property. (7) The joint venture owns a long-term leasehold interest in the retail space at 650 Fifth Avenue. In connection with the ground lease obligation, SLG provided a performance guaranty and our joint venture partner executed a contribution agreement to reflect its pro rata obligation. In the event the property is converted into a condominium unit and the landlord elects the purchase option, the joint venture shall be obligated to acquire the unit at the then fair value. (8) In February 2015, we acquired an interest in a portfolio of Manhattan residential and retail properties for $40.2 million , of which $3.5 million represented an increase in ownership interest in six of our existing consolidated joint venture properties. The $40.2 million of consideration included the issuance of $40.0 million aggregate liquidation preference of 3.75% Series M Preferred Units of limited partnership interest of the Operating Partnership. In July 2015, we acquired less than 1.0% of additional interest in the Stonehenge Portfolio for a net purchase price of $1.1 million . (9) In August 2015, we sold an 80% interest in 131-137 Spring Street. These properties, which were previously wholly-owned, were accounted for in the consolidated financial statements. See Note 4, "Properties Held for Sale and Property Dispositions." Acquisition, Development and Construction Arrangements Based on the characteristics of the following arrangements, which are similar to those of an investment, combined with the expected residual profit of not greater than 50% , we have accounted for these debt and preferred equity investments under the equity method. As of September 30, 2015 and December 31, 2014 , the carrying value for acquisition, development and construction arrangements were as follows (in thousands): Loan Type September 30, 2015 December 31, 2014 Initial Maturity Date Mezzanine loan and preferred equity $ 99,856 $ 99,629 March 2016 Mezzanine loan (1) 45,907 46,246 February 2022 $ 145,763 $ 145,875 ____________________________________________________________________ (1) We have an option to convert our loan to equity interest subject to certain conditions. In addition, we have determined that our option to convert the loan to equity is not a derivative financial instrument pursuant to Generally Accepted Accounting Principles, or GAAP. As such, the embedded feature is not required to be bifurcated and the fair value accounting for the embedded feature at each reporting date is not applicable. Sale of Joint Venture Interest or Property The following table summarizes the investments in unconsolidated joint ventures sold during the nine months ended September 30, 2015: Property Ownership Percentage Disposition Date Type of Sale Gross Asset Valuation (in millions) (1) Gain (Loss) on Sale (in millions) (2) The Meadows 50.00% August 2015 Property $ 121.1 $ (1.6 ) 315 West 36th Street 35.50% September 2015 Ownership Interest 115.0 16.3 ___________________________________________________________________ (1) Represents implied gross valuation of the property. (2) Represents our share of the gain or loss. The gain on sale for 315 West 36th Street is net of employee compensation awards accrued in connection with the realization of this investment gain as a bonus to certain employees that were instrumental in realizing the gain on sale. Mortgages and Other Loans Payable We generally finance our joint ventures with non-recourse debt. However, in certain cases we have provided guarantees or master leases for tenant space. These guarantees and master leases terminate upon the satisfaction of specified circumstances or repayment of the underlying loans. The first mortgage notes and other loans payable collateralized by the respective joint venture properties and assignment of leases at September 30, 2015 and December 31, 2014 , respectively, are as follows (amounts in thousands): Property Maturity Date Interest Rate (1) September 30, 2015 December 31, 2014 Fixed Rate Debt: 7 Renaissance December 2015 10.00 % $ 2,927 $ 2,147 11 West 34th Street January 2016 4.82 % 16,671 16,905 280 Park Avenue June 2016 6.57 % 694,846 700,171 1745 Broadway January 2017 5.68 % 340,000 340,000 Jericho Plaza (2) May 2017 5.65 % 163,750 163,750 800 Third Avenue August 2017 6.00 % 20,910 20,910 521 Fifth Avenue November 2019 3.73 % 170,000 170,000 Property Maturity Date Interest Rate (1) September 30, 2015 December 31, 2014 717 Fifth Avenue (3) July 2022 4.45 % 300,000 300,000 21 East 66th Street April 2023 3.60 % 12,000 12,000 717 Fifth Avenue (3) July 2024 9.00 % 322,769 314,381 3 Columbus Circle (4) March 2025 3.61 % 350,000 — Stonehenge Portfolio (5) Various 4.18 % 433,031 — 315 West 36th Street (6) — 25,000 Total fixed rate debt $ 2,826,904 $ 2,065,264 Floating Rate Debt: 1552 Broadway (7) April 2016 4.32 % 188,409 184,210 Other loan payable June 2016 1.09 % 30,000 30,000 650 Fifth Avenue (8) October 2016 3.70 % 65,000 65,000 175-225 Third Street December 2016 4.25 % 40,000 40,000 10 East 53rd Street February 2017 2.70 % 125,000 125,000 724 Fifth Avenue April 2017 2.62 % 275,000 275,000 33 Beekman (9) August 2017 2.94 % 71,378 52,283 600 Lexington Avenue October 2017 2.29 % 113,786 116,740 55 West 46th Street (10) October 2017 2.50 % 150,000 150,000 Stonehenge Portfolio December 2017 3.25 % 10,500 — 121 Greene Street November 2019 1.70 % 15,000 15,000 131-137 Spring Street August 2020 1.75 % 141,000 — 100 Park Avenue February 2021 1.95 % 360,000 360,000 21 East 66th Street June 2033 3.00 % 1,825 1,883 3 Columbus Circle (4) — 230,974 The Meadows (11) — 67,350 Total floating rate debt $ 1,586,898 $ 1,713,440 Total joint venture mortgages and other loans payable $ 4,413,802 $ 3,778,704 ____________________________________________________________________ (1) Effective weighted average interest rate for the three months ended September 30, 2015 , taking into account interest rate hedges in effect during the period. (2) This loan is in default as of June 30, 2015 due to the non-payment of debt service. (3) These loans are comprised of a $300.0 million fixed rate mortgage loan and $290.0 million mezzanine loan. The mezzanine loan is subject to accretion based on the difference between contractual interest rate and contractual pay rate. (4) In March 2015, the joint venture refinanced the previous mortgage and incurred a net loss on early extinguishment of debt of $0.8 million . (5) Amount is comprised of $13.4 million , $55.8 million , $35.0 million , $7.4 million , $142.1 million , and $179.4 million in fixed-rate mortgages that mature in July 2016, June 2017, November 2017, February 2018, August 2019, and June 2024, respectively. (6) In July 2015, the joint venture refinanced the previous mortgage. In September 2015, the interest in the property was sold for a gross asset valuation of $115.0 million . (7) These loans are comprised of a $150.0 million mortgage loan and a $41.5 million mezzanine loan. As of September 30, 2015 , $1.7 million of the mortgage loan and $1.4 million of the mezzanine loan was unfunded. (8) This loan has a committed amount of $97.0 million , of which $32.0 million was unfunded as of September 30, 2015 . (9) This loan has a committed amount of $75.0 million , of which $18.4 million is recourse to us. Our partner has indemnified us for its pro rata share of the recourse guarantee. A portion of the guarantee terminates upon the joint venture reaching certain milestones. We believe it is unlikely that we will be required to perform under this guarantee. (10) This loan has a committed amount of $190.0 million , of which $40.0 million was unfunded as of September 30, 2015 . (11) In August 2015, these properties were sold and the debt was repaid. We act as the operating partner and day-to-day manager for all our joint ventures, except for 800 Third Avenue, Jericho Plaza, 280 Park Avenue, 3 Columbus Circle, 21 East 66th Street, 175-225 Third Street and the Stonehenge Portfolio. We are entitled to receive fees for providing management, leasing, construction supervision and asset management services to certain of our joint ventures. We earned $1.9 million , $6.8 million , $3.8 million and $15.0 million from these services for the three and nine months ended September 30, 2015 and 2014 , respectively. In addition, we have the ability to earn incentive fees based on the ultimate financial performance of certain of the joint venture properties. The combined balance sheets for the unconsolidated joint ventures, at September 30, 2015 and December 31, 2014, are as follows (in thousands): September 30, 2015 December 31, 2014 Assets Commercial real estate property, net $ 6,282,267 $ 5,275,632 Other assets 906,955 810,567 Total assets $ 7,189,222 $ 6,086,199 Liabilities and members' equity Mortgages and other loans payable $ 4,413,802 $ 3,778,704 Other liabilities 501,637 485,572 Members' equity 2,273,783 1,821,923 Total liabilities and members' equity $ 7,189,222 $ 6,086,199 Company's investments in unconsolidated joint ventures $ 1,239,008 $ 1,172,020 The combined statements of income for the unconsolidated joint ventures, from acquisition date through the three and nine months ended September 30, 2015 and 2014 are as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Total revenues $ 150,638 $ 114,831 $ 423,089 $ 406,464 Operating expenses 27,647 18,530 79,478 63,575 Ground rent 4,677 2,638 9,841 7,295 Real estate taxes 23,494 15,867 65,205 48,209 Interest expense, net of interest income 51,430 40,885 147,152 137,949 Amortization of deferred financing costs 3,473 2,837 9,628 9,496 Transaction related costs 604 501 615 565 Depreciation and amortization 38,144 28,324 109,022 107,786 Total expenses 149,469 109,582 420,941 374,875 Loss on early extinguishment of debt (248 ) — (1,081 ) (6,743 ) Net income before gain on sale $ 921 $ 5,249 $ 1,067 $ 24,846 Company's equity in net income from unconsolidated joint ventures $ 3,627 $ 6,034 $ 10,651 $ 20,781

Deferred Costs

Deferred Costs	9 Months Ended
	Sep. 30, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs	Deferred Costs Deferred costs at September 30, 2015 and December 31, 2014 consisted of the following (in thousands): September 30, 2015 December 31, 2014 Deferred leasing $ 405,278 $ 385,555 Deferred financing 211,552 193,776 616,830 579,331 Less accumulated amortization (273,894 ) (251,369 ) Deferred costs, net $ 342,936 $ 327,962

Mortgages and Other Loans Payab

Mortgages and Other Loans Payable	9 Months Ended
	Sep. 30, 2015
Mortgages and Other Loans Payable
Mortgages and Other Loans Payable	Mortgages and Other Loans Payable The first mortgages and other loans payable collateralized by the respective properties and assignment of leases at September 30, 2015 and December 31, 2014 , respectively, were as follows (amounts in thousands): Property Maturity Date Interest Rate (1) September 30, 2015 December 31, 2014 Fixed Rate Debt: FHLB Facility October 2015 (2) 0.46 % $ 1,000 $ — 500 West Putnam Avenue January 2016 5.52 % 22,527 22,968 Landmark Square December 2016 4.00 % 79,995 81,269 485 Lexington Avenue February 2017 5.61 % 450,000 450,000 762 Madison Avenue (3) February 2017 3.86 % 7,916 8,045 885 Third Avenue July 2017 6.26 % 267,650 267,650 1745 Broadway June 2018 4.81 % 16,000 16,000 388-390 Greenwich Street (4) June 2018 3.25 % 1,004,000 1,004,000 One Madison Avenue May 2020 5.91 % 548,699 565,742 100 Church Street July 2022 4.68 % 226,000 228,612 919 Third Avenue (5) June 2023 5.12 % 500,000 500,000 400 East 57th Street February 2024 4.13 % 67,962 68,896 400 East 58th Street February 2024 4.13 % 29,126 29,527 420 Lexington Avenue October 2024 3.99 % 300,000 300,000 1515 Broadway March 2025 3.93 % 900,000 900,000 11 Madison Avenue September 2025 3.84 % 1,400,000 — Series J Preferred Units (6) April 2051 3.75 % 4,000 4,000 711 Third Avenue (7) — 120,000 120 West 45th Street (8) — 170,000 Total fixed rate debt $ 5,824,875 $ 4,736,709 Floating Rate Debt: Master Repurchase Agreement June 2016 3.35 % 285,508 100,000 FHLB Facility June 2016 0.53 % 5,000 — 388-390 Greenwich Street (4) June 2018 1.94 % 446,000 446,000 248-252 Bedford Avenue June 2019 1.70 % 29,000 29,000 220 East 42nd Street October 2020 1.80 % 275,000 275,000 180 Maiden Lane (9) — 253,942 Total floating rate debt $ 1,040,508 $ 1,103,942 Total fixed rate and floating rate debt $ 6,865,383 $ 5,840,651 Mortgages reclassed to liabilities related to assets held for sale — (253,942 ) Total mortgages and other loans payable $ 6,865,383 $ 5,586,709 ____________________________________________________________________ (1) Effective weighted average interest rate for the three months ended September 30, 2015 , taking into account interest rate hedges in effect during the period. (2) In October 2015, the maturity date was extended to April 2016. (3) In February 2015, we entered into a new swap agreement with a fixed interest rate of 3.86% per annum, which replaced the previous swap agreement with a fixed interest rate of 3.75% per annum. (4) In connection with the acquisition of our joint venture partner's interest, we assumed the existing derivative instruments, which swapped $504.0 million of the mortgage to a fixed rate mortgage which bears interest at 3.80% per annum. In October 2014, we entered into multiple swap agreements to hedge our interest rate exposure on the additional $500.0 million portion of this mortgage, which was swapped to a fixed rate of 2.69% per annum. Including the as-of right extension option, this loan matures in June 2021. (5) We own a 51.0% controlling interest in the joint venture that is the borrower on this loan. (6) In connection with the acquisition of a commercial real estate property, the Operating Partnership issued $4.0 million , or 4,000 , 3.75% Series J Preferred Units of limited partnership interest, or the Series J Preferred Units, with a mandatory liquidation preference of $1,000.00 per unit. The Series J Preferred Units are accounted for as debt because they can be redeemed in cash by the Operating Partnership on the earlier of (i) the date of the sale of the property or (ii) April 30, 2051 or at the option of the unitholders as further prescribed in the related agreement. (7) In March 2015, we repaid the mortgage. (8) This property was sold in September 2015 and all obligations related to the property accruing on and after the closing date were assumed by the purchaser. (9) This property was held for sale at December 31, 2014 and the related mortgage is included in liabilities related to assets held for sale. In January 2015, the property was sold and the debt was repaid. Federal Home Loan Bank of New York Facility During the third quarter of 2015, the Company’s wholly-owned subsidiary, Belmont Insurance Company ("Belmont"), a New York licensed captive insurance company, became a member of the Federal Home Loan Bank of New York ("FHLBNY"). As a member, Belmont may borrow funds from the FHLBNY in the form of secured advances. As of September 30, 2015, we had $6.0 million in outstanding secured advances with a weighted average borrowing rate of 0.52% . Master Repurchase Agreement The Master Repurchase Agreement, as amended in December 2013, or MRA, provides us with the ability to sell certain debt investments with a simultaneous agreement to repurchase the same at a certain date or on demand. This MRA has a maximum facility capacity of $300.0 million and bears interest ranging from 250 and 325 basis points over 30-day LIBOR depending on the pledged collateral. In September 30, 2015 we entered into an amendment to the MRA to extend the maturity to June 29, 2016. Further, as of December 6, 2015 we will be required to pay monthly in arrears a 25 basis point fee on the excess of $150.0 million over the average daily balance during the period if the average daily balance is less than $150.0 million . We seek to mitigate risks associated with our repurchase agreement by managing the credit quality of our assets, early repayments, interest rate volatility, liquidity, and market value. The margin call provisions under our repurchase facility permit valuation adjustments based on capital markets activity, and are not limited to collateral-specific credit marks. To monitor credit risk associated with our debt investments, our asset management team regularly reviews our investment portfolio and is in contact with our borrowers in order to monitor the collateral and enforce our rights as necessary. The risk associated with potential margin calls is further mitigated by our ability to recollateralize the facility with additional assets from our portfolio of debt investments, our ability to satisfy margin calls with cash or cash equivalents and access to additional liquidity through the 2012 Credit Facility. At September 30, 2015 and December 31, 2014 , the gross book value of the properties and debt and preferred equity investments collateralizing the mortgages and other loans payable was approximately $10.5 billion and $8.2 billion , respectively.

Corporate Indebtedness

Corporate Indebtedness	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Corporate Indebtedness	Corporate Indebtedness 2012 Credit Facility In July 2015, we entered into the third amendment to the credit facility entered into by the Company in November 2012, or the 2012 credit facility, which increased our unsecured corporate facility by $500.0 million . The revolving credit facility was increased by $400.0 million to $1.6 billion and the term loan portion of the facility was increased by $100.0 million to $933.0 million . In January 2015, we amended the 2012 credit facility by entering into a second amended and restated credit agreement, which decreased the interest-rate margin and facility fee applicable to the revolving credit facility by 20 basis points and five basis points, respectively, and extended the maturity date of the revolving credit facility to March 29, 2019 with an as-of-right extension through March 29, 2020. In November 2014, we increased the term loan portion of the facility by $50.0 million to $833.0 million . In March 2014, we entered into an amendment to the 2012 credit facility, which among other things, increased the term loan portion of the facility by $383.0 million to $783.0 million , decreased the interest-rate margin applicable to the term loan portion of the facility by 25 basis points and extended the maturity of the term loan portion of the facility from March 30, 2018 to June 30, 2019. As of September 30, 2015 , the 2012 credit facility, as amended, consisted of a $1.6 billion revolving credit facility, or the revolving credit facility, and an $933.0 million term loan, or the term loan facility. We also have an option, subject to customary conditions, to increase the capacity under the revolving credit facility to $3.0 billion at any time prior to the maturity date for the revolving credit facility without the consent of existing lenders, by obtaining additional commitments from our existing lenders and other financial institutions. As of September 30, 2015 , the 2012 credit facility bore interest at a spread over LIBOR ranging from (i) 87.5 basis points to 155 basis points for loans under the revolving credit facility and (ii) 95 basis points to 190 basis points for loans under the term loan facility, in each case based on the credit rating assigned to the senior unsecured long term indebtedness of ROP. At September 30, 2015 , the applicable spread was 125 basis points for revolving credit facility and 140 basis points for the term loan facility. At September 30, 2015 , the effective interest rate was 1.44% for the revolving credit facility and 1.66% for the term loan facility. We are required to pay quarterly in arrears a 12.5 to 30 basis point facility fee on the total commitments under the revolving credit facility based on the credit rating assigned to the senior unsecured long term indebtedness of ROP. As of September 30, 2015 , the facility fee was 25 basis points. As of September 30, 2015 , we had $81.2 million of outstanding letters of credit, $949.0 million drawn under the revolving credit facility and $933.0 million outstanding under the term loan facility, with total undrawn capacity of $569.8 million under the 2012 credit facility. The Company, the Operating Partnership and ROP are all borrowers jointly and severally obligated under the 2012 credit facility. None of our other subsidiaries are obligors under the 2012 credit facility. The 2012 credit facility includes certain restrictions and covenants (see Restrictive Covenants below). Senior Unsecured Notes The following table sets forth our senior unsecured notes and other related disclosures as of September 30, 2015 and December 31, 2014 , respectively, by scheduled maturity date (dollars in thousands): Issuance September 30, 2015 Unpaid Principal Balance September 30, 2015 Accreted Balance December 31, 2014 Accreted Balance Coupon Rate (1) Effective Rate Term (in Years) Maturity Date March 31, 2006 (2) $ 255,308 $ 255,284 $ 255,250 6.00 % 6.00 % 10 March 31, 2016 October 12, 2010 (3) 345,000 318,035 309,069 3.00 % 3.00 % 7 October 15, 2017 August 5, 2011 (4) 250,000 249,793 249,744 5.00 % 5.00 % 7 August 15, 2018 March 16, 2010 (4) 250,000 250,000 250,000 7.75 % 7.75 % 10 March 15, 2020 November 15, 2012 (4) 200,000 200,000 200,000 4.50 % 4.50 % 10 December 1, 2022 March 26, 2007 (5) 10,008 10,008 10,008 3.00 % 3.00 % 20 March 30, 2027 June 27, 2005 (2)(6) — — 7 $ 1,310,316 $ 1,283,120 $ 1,274,078 ____________________________________________________________________ (1) Interest on the senior unsecured notes is payable semi-annually with principal and unpaid interest due on the scheduled maturity dates. (2) Issued by ROP. (3) Issued by the Operating Partnership. Interest on these exchangeable notes is payable semi-annually on April 15 and October 15. The notes had an initial exchange rate representing an exchange price that was set at a 30.0% premium to the last reported sale price of SL Green's common stock on October 6, 2010, or $85.81 . The initial exchange rate is subject to adjustment under certain circumstances. The current exchange rate is 12.2732 shares of SL Green's common stock per $1,000 principal amount of these notes. The notes are senior unsecured obligations of the Operating Partnership and are exchangeable upon the occurrence of specified events and during the period beginning on the twenty-second scheduled trading day prior to the maturity date and ending on the second business day prior to the maturity date, into cash or a combination of cash and shares of SL Green's common stock, if any, at our option. As a result of meeting specified events (as defined in the Indenture Agreement), these notes became exchangeable commencing January 1, 2015 and will remain exchangeable through September 30, 2015. The notes are guaranteed by ROP. On the issuance date, $78.3 million of the debt balance was recorded in equity. As of September 30, 2015 , $27.0 million remained to be amortized into the debt balance. (4) Issued by the Company, the Operating Partnership and ROP, as co-obligors. (5) Issued by the Operating Partnership. Interest on these remaining exchangeable notes is payable semi-annually on March 30 and September 30. The notes have an initial exchange rate representing an exchange price that was set at a 25.0% premium to the last reported sale price of the Company's common stock on March 20, 2007, or $173.30 . The initial exchange rate is subject to adjustment under certain circumstances. The current exchange rate is 5.7952 shares of SL Green's common stock per $1,000 principal amount of these notes. The notes are senior unsecured obligations of the Operating Partnership and are exchangeable upon the occurrence of specified events and during the period beginning on the twenty-second scheduled trading day prior to the maturity date and ending on the second business day prior to the maturity date, into cash or a combination of cash and shares of SL Green's common stock, if any, at our option. The notes are currently redeemable at the Operating Partnership’s option. The Operating Partnership may be required to repurchase the notes on March 30, 2017 and 2022, and upon the occurrence of certain designated events. (6) In April 2015, we redeemed the remaining outstanding debentures. Restrictive Covenants The terms of the 2012 credit facility, as amended, and certain of our senior unsecured notes include certain restrictions and covenants which may limit, among other things, our ability to pay dividends, make certain types of investments, incur additional indebtedness, incur liens and enter into negative pledge agreements and dispose of assets, and which require compliance with financial ratios relating to the maximum ratio of total indebtedness to total asset value, a minimum ratio of EBITDA to fixed charges, a maximum ratio of secured indebtedness to total asset value and a maximum ratio of unsecured indebtedness to unencumbered asset value. The dividend restriction referred to above provides that, we will not during any time when a default is continuing, make distributions with respect to common stock or other equity interests, except to enable the Company to continue to qualify as a REIT for Federal income tax purposes. As of September 30, 2015 and December 31, 2014 , we were in compliance with all such covenants. Junior Subordinated Deferrable Interest Debentures In June 2005, the Company and the Operating Partnership issued $100.0 million in unsecured trust preferred securities through a newly formed trust, SL Green Capital Trust I, or the Trust, which is a wholly-owned subsidiary of the Operating Partnership. The securities mature in 2035 and bear interest at a fixed rate of 5.61% for the first ten years ending July 2015. Thereafter, the interest rate will float at 125 basis points over the three-month LIBOR. Interest payments may be deferred for a period of up to eight consecutive quarters if the Operating Partnership exercises its right to defer such payments. The Trust preferred securities are redeemable at the option of the Operating Partnership, in whole or in part, with no prepayment premium. We do not consolidate the Trust even though it is a variable interest entity as we are not the primary beneficiary. Because the Trust is not consolidated, we have recorded the debt on our consolidated balance sheets and the related payments are classified as interest expense. Principal Maturities Combined aggregate principal maturities of mortgages and other loans payable, 2012 credit facility, trust preferred securities, senior unsecured notes and our share of joint venture debt as of September 30, 2015 , including as-of-right extension options and put options, were as follows (in thousands): Scheduled Amortization Principal Repayments Revolving Credit Facility Unsecured Term Loan Trust Preferred Securities Senior Unsecured Notes Total Joint Venture Debt Remaining 2015 $ 7,716 $ 1,000 $ — $ — $ — $ — $ 8,716 $ 2,961 2016 47,360 390,819 — — — 255,308 693,487 534,036 2017 61,063 725,329 — — — 355,008 1,141,400 580,044 2018 64,462 16,000 — — — 250,000 330,462 2,196 2019 70,409 28,317 — 933,000 — — 1,031,726 104,687 Thereafter 200,403 5,252,505 949,000 — 100,000 450,000 6,951,908 474,942 $ 451,413 $ 6,413,970 $ 949,000 $ 933,000 $ 100,000 $ 1,310,316 $ 10,157,699 $ 1,698,866 Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Interest expense $ 84,917 $ 83,158 $ 237,847 $ 238,285 Interest income (776 ) (782 ) (2,153 ) (1,861 ) Interest expense, net $ 84,141 $ 82,376 $ 235,694 $ 236,424 Interest capitalized $ 7,327 $ 7,972 $ 23,496 $ 18,689

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Cleaning/ Security/ Messenger and Restoration Services Through Alliance Building Services, or Alliance, First Quality Maintenance, L.P., or First Quality, provides cleaning, extermination and related services, Classic Security LLC provides security services, Bright Star Couriers LLC provides messenger services, and Onyx Restoration Works provides restoration services with respect to certain properties owned by us. Alliance is partially owned by Gary Green, a son of Stephen L. Green, the chairman of SL Green's board of directors. In addition, First Quality has the non-exclusive opportunity to provide cleaning and related services to individual tenants at our properties on a basis separately negotiated with any tenant seeking such additional services. The Service Corporation has entered into an arrangement with Alliance whereby it will receive a profit participation above a certain threshold for services provided by Alliance to certain tenants at certain buildings above the base services specified in their lease agreements. Income earned from profit participation, which is included in other income on the consolidated statements of operations, was $0.9 million for both the three months ended September 30, 2015 and 2014, and $2.9 million and $2.8 million for the nine months ended September 30, 2015 and 2014, respectively. We also recorded expenses of $5.7 million , $14.3 million , $5.9 million and $14.7 million for the three and nine months ended September 30, 2015 and 2014 , respectively, for these services (excluding services provided directly to tenants). Management Fees S.L. Green Management Corp., a consolidated entity, receives property management fees from an entity in which Stephen L. Green owns an interest. We received management fees from such entity of $0.1 million for both the three months ended September 30, 2015 and 2014, and $0.4 million and $0.3 million for the nine months ended September 30, 2015 and 2014, respectively. Other Amounts due from related parties at September 30, 2015 and December 31, 2014 consisted of the following (in thousands): September 30, 2015 December 31, 2014 Due from joint ventures $ 1,343 $ 1,254 Other 9,746 10,481 Related party receivables $ 11,089 $ 11,735

Noncontrolling Interests on the

Noncontrolling Interests on the Company's Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2015
Noncontrolling Interest [Abstract]
Noncontrolling Interests on the Company's Consolidated Financial Statements	Noncontrolling Interests on the Company's Consolidated Financial Statements Noncontrolling interests represent the common and preferred units of limited partnership interest in the Operating Partnership not held by the Company as well as third party equity interests in our other consolidated subsidiaries. Noncontrolling interests in the Operating Partnership are shown in the mezzanine equity while the noncontrolling interests in our other consolidated subsidiaries are shown in the equity section of the Company’s consolidated financial statements. Common Units of Limited Partnership Interest in the Operating Partnership As of September 30, 2015 and December 31, 2014, the noncontrolling interest unit holders owned 3.74% , or 3,874,750 units, and 3.92% , or 3,973,016 units, of the Operating Partnership, respectively. At September 30, 2015 , 3,874,750 shares of SL Green's common stock were reserved for issuance upon redemption of units of limited partnership interest of the Operating Partnership. Noncontrolling interests in the Operating Partnership is recorded at the greater of its cost basis or fair market value based on the closing stock price of SL Green's common stock at the end of the reporting period. Below is the rollforward analysis of the activity relating to the noncontrolling interests in the Operating Partnership as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Balance at beginning of period $ 469,524 $ 265,476 Distributions (7,017 ) (7,849 ) Issuance of common units 27,898 56,469 Redemption of common units (41,605 ) (31,653 ) Net income 6,634 18,467 Accumulated other comprehensive income allocation (349 ) 175 Fair value adjustment (31,664 ) 168,439 Balance at end of period $ 423,421 $ 469,524 Preferred Units of Limited Partnership Interest in the Operating Partnership The Operating Partnership has 1,902,000 4.50% Series G Preferred Units of limited partnership interest, or the Series G Preferred Units outstanding, with a liquidation preference of $25.00 per unit, which were issued in January 2012 in conjunction with an acquisition. The Series G Preferred unitholders receive annual dividends of $1.125 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series G Preferred Units are convertible into a number of common units of limited partnership interest in the Operating Partnership equal to (i) the liquidation preference plus accumulated and unpaid distributions on the conversion date divided by (ii) $88.50 . The common units of limited partnership interest in the Operating Partnership may be redeemed in exchange for SL Green's common stock on a 1 -to-1 basis. The Series G Preferred Units also provide the holder with the right to require the Operating Partnership to repurchase the Series G Preferred Units for cash before January 31, 2022. The Operating Partnership has 60 Series F Preferred Units outstanding with a mandatory liquidation preference of $1,000.00 per unit. The Operating Partnership has authorized up to 700,000 3.50% Series K Preferred Units of limited partnership interest, or the Series K Preferred Units, with a liquidation preference of $25.00 per unit. In August 2014, the Company issued 563,954 Series K Preferred Units in conjunction with an acquisition. The Series K Preferred unitholders receive annual dividends of $0.875 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series K Preferred Units can be redeemed at any time, at the option of the unitholder, either for cash or are convertible into a number of common units of limited partnership interest in the Operating Partnership equal to (i) the liquidation preference plus accumulated and unpaid distributions on the conversion date divided by (ii) $134.67 . The Operating Partnership has authorized up to 500,000 4.00% Series L Preferred Units of limited partnership interest, or the Series L Preferred Units, with a liquidation preference of $25.00 per unit. In August 2014, the Company issued 378,634 Series L Preferred Units in conjunction with an acquisition. The Series L Preferred unitholders receive annual dividends of $1.00 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series L Preferred Units can be redeemed at any time at par for cash at the option of the unitholder. The Operating Partnership has authorized up to 1,600,000 3.75% Series M Preferred Units of limited partnership interest, or the Series M Preferred Units, with a liquidation preference of $25.00 per unit. In February 2015, the Company issued 1,600,000 Series M Preferred Units in conjunction with the acquisition of ownership interests in and relating to certain residential and retail real estate properties. The Series M Preferred unitholders receive annual dividends of $0.9375 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series M Preferred Units can be redeemed at any time at par for cash at the option of the unitholder. The Operating Partnership has authorized up to 552,303 3.00% Series N Preferred Units of limited partnership interest, or the Series N Preferred Units, with a liquidation preference of $25.00 per unit. In June 2015, the Company issued 552,303 Series N Preferred Units in conjunction with an acquisition. The Series N Preferred unitholders receive annual dividends of $0.75 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series N Preferred Units can be redeemed at any time at par for cash at the option of the unitholder. The Operating Partnership has authorized an aggregate of one 6.25% Series O Preferred Unit of limited partnership interest, or the Series O Preferred Unit. In June 2015, the Company issued the Series O Preferred Unit in connection with an acquisition. The Operating Partnership has authorized up to 200,000 4.00% Series P Preferred Units of limited partnership interest, or the Series P Preferred Units, with a liquidation preference of $25.00 per unit. In July 2015, the Company issued 200,000 Series P Preferred Units in conjunction with an acquisition. The Series P Preferred unitholders receive annual dividends of $1.00 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series P Preferred Units can be redeemed at any time at par for cash at the option of the unitholder. The Operating Partnership has authorized up to 268,000 3.50% Series Q Preferred Units of limited partnership interest, or the Series Q Preferred Units, with a liquidation preference of $25.00 per unit. In July 2015, the Company issued 268,000 Series Q Preferred Units in conjunction with an acquisition. The Series Q Preferred unitholders receive annual dividends of $0.875 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series Q Preferred Units can be redeemed at any time, at the option of the unitholder, either for cash or are convertible into a number of common units of limited partnership interest in the Operating Partnership equal to (i) the liquidation preference plus accumulated and unpaid distributions on the conversion date divided by (ii) $148.95 . The Operating Partnership has authorized up to 400,000 3.50% Series R Preferred Units of limited partnership interest, or the Series R Preferred Units, with a liquidation preference of $25.00 per unit. In August 2015, the Company issued 400,000 Series R Preferred Units in conjunction with an acquisition. The Series R Preferred unitholders receive annual dividends of $0.875 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series R Preferred Units can be redeemed at any time, at the option of the unitholder, either for cash or are convertible into a number of common units of limited partnership interest in the Operating Partnership equal to (i) the liquidation preference plus accumulated and unpaid distributions on the conversion date divided by (ii) $154.89 . The Operating Partnership has authorized up to 1,077,280 4.00% Series S Preferred Units of limited partnership interest, or the Series S Preferred Units, with a liquidation preference of $25.00 per unit. In August 2015, the Company issued 1,077,280 Series S Preferred Units in conjunction with an acquisition. The Series S Preferred unitholders receive annual dividends of $1.00 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Series S Preferred Units can be redeemed at any time at par for cash at the option of the unitholder. T hrough a consolidated subsidiary, we have authorized up to 109,161 3.5% Series A Preferred Units of limited partnership interest, or the Greene Series A Preferred Units, with a liquidation preference of $1,000.00 per unit. In August 2015, the Company issued 109,161 Greene Series A Preferred Units in conjunction with an acquisition. The Greene Series A Preferred unitholders receive annual dividends of $35.00 per unit paid on a quarterly basis and dividends are cumulative, subject to certain provisions. The Greene Series A Preferred Units can be redeemed at any time, at the option of the unitholder, either for cash or are convertible on a one-for-one basis, into the Series B Preferred Units of limited partnership interest, or the Greene Series B Preferred Units. The Greene Series B Preferred Units can be converted at any time, at the option of the unitholder, into a number of common stock equal to 6.71348 shares of common stock for each Greene Series B Preferred Unit. As of September 30, 2015, no Greene Series B Preferred Units have been issued. Below is the rollforward analysis of the activity relating to the preferred units in the Operating Partnership as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Balance at beginning of period $ 71,115 $ 49,550 Issuance of preferred units 211,601 23,565 Redemption of preferred units (200 ) (2,000 ) Balance at end of period $ 282,516 $ 71,115

Stockholders' Equity of the Com

Stockholders' Equity of the Company	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Stockholders' Equity of the Company	Stockholders’ Equity of the Company Common Stock Our authorized capital stock consists of 260,000,000 shares, $0.01 par value per share, consisting of 160,000,000 shares of common stock, $0.01 par value per share, 75,000,000 shares of excess stock, at $0.01 par value per share, and 25,000,000 shares of preferred stock, par value $0.01 per share. As of September 30, 2015 , 99,659,376 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In June 2014, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $300.0 million of SL Green's common stock. During the three months ended March 31, 2015, we sold 895,956 shares of our common stock for aggregate net proceeds of $113.4 million comprising the remaining balance of this ATM Program. The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 895,956 units of limited partnership interest of the Operating Partnership. In March 2015, the Company, along with the Operating Partnership, entered into a new ATM Program to sell an aggregate of $300.0 million of SL Green's common stock. During the nine months ended September 30, 2015 , we sold 91,180 shares of our common stock for aggregate net proceeds of $12.0 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 91,180 units of limited partnership interest of the Operating Partnership. As of September 30, 2015 , $288.0 million remained available for issuance of common stock under the new ATM program. Perpetual Preferred Stock We have 9,200,000 shares of our 6.50% Series I Cumulative Redeemable Preferred Stock, or the Series I Preferred Stock, outstanding with a mandatory liquidation preference of $25.00 per share. The Series I Preferred stockholders receive annual dividends of $1.625 per share paid on a quarterly basis and dividends are cumulative, subject to certain provisions. We are entitled to redeem the Series I Preferred Stock at par for cash at our option on or after August 10, 2017. In August 2012, we received $221.9 million in net proceeds from the issuance of the Series I Preferred Stock, which were recorded net of underwriters' discount and issuance costs, and contributed the net proceeds to the Operating Partnership in exchange for 9,200,000 units of 6.50% Series I Cumulative Redeemable Preferred Units of limited partnership interest, or the Series I Preferred Units. Dividend Reinvestment and Stock Purchase Plan In February 2015, the Company filed a registration statement with the SEC for our dividend reinvestment and stock purchase plan, or DRSPP, which automatically became effective upon filing. The Company registered 3,500,000 shares of SL Green's common stock under the DRSPP. The DRSPP commenced on September 24, 2001. During the nine months ended September 30, 2015 , the Company issued 775,529 shares of SL Green's common stock and received net proceeds of $99.5 million of proceeds from dividend reinvestments and/or stock purchases under the DRSPP. DRSPP shares may be issued at a discount to the market price. Earnings per Share SL Green's earnings per share for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic Earnings: Income attributable to SL Green common stockholders $ 163,658 $ 64,688 $ 167,829 $ 446,319 Effect of Dilutive Securities: Redemption of units to common shares 6,468 2,636 6,634 16,010 Diluted Earnings: Income attributable to SL Green common stockholders $ 170,126 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic Shares: Weighted average common stock outstanding 99,621 95,734 99,205 95,437 Effect of Dilutive Securities: Redemption of units to common shares 3,901 3,585 3,924 3,423 Stock-based compensation plans 407 387 480 462 Diluted weighted average common stock outstanding 103,929 99,706 103,609 99,322 SL Green has excluded 263,236 , 233,586 , 231,970 and 769,790 common stock equivalents from the diluted shares outstanding for the three and nine months ended September 30, 2015 and 2014, respectively, as they were anti-dilutive.

Partners' Capital of the Operat

Partners' Capital of the Operating Partnership	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity
Partners' Capital of the Operating Partnership	Stockholders’ Equity of the Company Common Stock Our authorized capital stock consists of 260,000,000 shares, $0.01 par value per share, consisting of 160,000,000 shares of common stock, $0.01 par value per share, 75,000,000 shares of excess stock, at $0.01 par value per share, and 25,000,000 shares of preferred stock, par value $0.01 per share. As of September 30, 2015 , 99,659,376 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In June 2014, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $300.0 million of SL Green's common stock. During the three months ended March 31, 2015, we sold 895,956 shares of our common stock for aggregate net proceeds of $113.4 million comprising the remaining balance of this ATM Program. The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 895,956 units of limited partnership interest of the Operating Partnership. In March 2015, the Company, along with the Operating Partnership, entered into a new ATM Program to sell an aggregate of $300.0 million of SL Green's common stock. During the nine months ended September 30, 2015 , we sold 91,180 shares of our common stock for aggregate net proceeds of $12.0 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 91,180 units of limited partnership interest of the Operating Partnership. As of September 30, 2015 , $288.0 million remained available for issuance of common stock under the new ATM program. Perpetual Preferred Stock We have 9,200,000 shares of our 6.50% Series I Cumulative Redeemable Preferred Stock, or the Series I Preferred Stock, outstanding with a mandatory liquidation preference of $25.00 per share. The Series I Preferred stockholders receive annual dividends of $1.625 per share paid on a quarterly basis and dividends are cumulative, subject to certain provisions. We are entitled to redeem the Series I Preferred Stock at par for cash at our option on or after August 10, 2017. In August 2012, we received $221.9 million in net proceeds from the issuance of the Series I Preferred Stock, which were recorded net of underwriters' discount and issuance costs, and contributed the net proceeds to the Operating Partnership in exchange for 9,200,000 units of 6.50% Series I Cumulative Redeemable Preferred Units of limited partnership interest, or the Series I Preferred Units. Dividend Reinvestment and Stock Purchase Plan In February 2015, the Company filed a registration statement with the SEC for our dividend reinvestment and stock purchase plan, or DRSPP, which automatically became effective upon filing. The Company registered 3,500,000 shares of SL Green's common stock under the DRSPP. The DRSPP commenced on September 24, 2001. During the nine months ended September 30, 2015 , the Company issued 775,529 shares of SL Green's common stock and received net proceeds of $99.5 million of proceeds from dividend reinvestments and/or stock purchases under the DRSPP. DRSPP shares may be issued at a discount to the market price. Earnings per Share SL Green's earnings per share for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic Earnings: Income attributable to SL Green common stockholders $ 163,658 $ 64,688 $ 167,829 $ 446,319 Effect of Dilutive Securities: Redemption of units to common shares 6,468 2,636 6,634 16,010 Diluted Earnings: Income attributable to SL Green common stockholders $ 170,126 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic Shares: Weighted average common stock outstanding 99,621 95,734 99,205 95,437 Effect of Dilutive Securities: Redemption of units to common shares 3,901 3,585 3,924 3,423 Stock-based compensation plans 407 387 480 462 Diluted weighted average common stock outstanding 103,929 99,706 103,609 99,322 SL Green has excluded 263,236 , 233,586 , 231,970 and 769,790 common stock equivalents from the diluted shares outstanding for the three and nine months ended September 30, 2015 and 2014, respectively, as they were anti-dilutive.
SL Green Operating Partnership
Stockholders' Equity
Partners' Capital of the Operating Partnership	Partners' Capital of the Operating Partnership The Company is the sole general partner of the Operating Partnership and at September 30, 2015 owned 99,659,376 general and limited partnership interests in the Operating Partnership and 9,200,000 Series I Preferred Units. Partnership interests in the Operating Partnership are denominated as “common units of limited partnership interest” (also referred to as “OP Units”) or “preferred units of limited partnership interest” (also referred to as “Preferred Units”). All references to OP Units and Preferred Units outstanding exclude such units held by the Company. A holder of an OP Unit may present such OP Unit to the Operating Partnership for redemption at any time (subject to restrictions agreed upon at the issuance of OP Units to particular holders that may restrict such right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, the Operating Partnership must redeem such OP Unit in exchange for the cash equal to the then value of a share of common stock of the Company, except that the Company may, at its election, in lieu of cash redemption, acquire such OP Unit for one share of common stock. Because the number of shares of common stock outstanding at all times equals the number of OP Units that the Company owns, one share of common stock is generally the economic equivalent of one OP Unit, and the quarterly distribution that may be paid to the holder of an OP Unit equals the quarterly dividend that may be paid to the holder of a share of common stock. Each series of Preferred Units makes a distribution that is set in accordance with an amendment to the partnership agreement of the Operating Partnership. Preferred Units may also be convertible into OP Units at the election of the holder thereof or the Company, subject to the terms of such Preferred Units. Net income (loss) allocated to the preferred unitholders and common unitholders reflects their pro rata share of net income (loss) and distributions. Limited Partner Units As of September 30, 2015 , limited partners other than SL Green owned 3.74% , or 3,874,750 common units, of the Operating Partnership. Preferred Units Preferred units not owned by SL Green are further described in Note 11, “Noncontrolling Interests on the Company’s Consolidated Financial Statements - Preferred Units of Limited Partnership Interest in the Operating Partnership.” Earnings per Unit The Operating Partnership's earnings per unit for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic and Diluted Earnings: Income attributable to SLGOP common unitholders $ 170,125 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic units: Weighted average common units outstanding 103,522 99,319 103,129 98,860 Effect of Dilutive Securities: Stock-based compensation plans 407 387 480 462 Diluted weighted average common units outstanding 103,929 99,706 103,609 99,322 The Operating Partnership has excluded 263,236 , 233,586 , 231,970 and 769,790 common unit equivalents from the diluted units outstanding for the three and nine months ended September 30, 2015 and 2014, respectively, as they were anti-dilutive. Accumulated Other Comprehensive Loss of the Operating Partnership The following tables set forth the changes in accumulated other comprehensive income (loss) by component as of September 30, 2015 (in thousands): Net unrealized (loss) gain on derivative instruments ( 1 ) SLGOP’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Unrealized gain (loss) on marketable securities Total Balance at December 31, 2014 $ (9,845 ) $ (100 ) $ 2,689 $ (7,256 ) Other comprehensive loss before reclassifications (15,537 ) (2,486 ) (337 ) (18,360 ) Amounts reclassified from accumulated other comprehensive income 8,221 949 — 9,170 Balance at September 30, 2015 $ (17,161 ) $ (1,637 ) $ 2,352 $ (16,446 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of September 30, 2015 and December 31, 2014, the deferred net losses from these terminated hedges, which is included in accumulated other comprehensive loss relating to net unrealized loss on derivative instrument, was $10.7 million and $12.2 million , respectively. (2) Amount reclassified from accumulated other comprehensive income (loss) is included in equity in net income from unconsolidated joint ventures in the respective consolidated statements of operations.

Share-based Compensation

Share-based Compensation	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation	Share-based Compensation We have stock-based employee and director compensation plans. Our employees are compensated through the Operating Partnership. Under each plan, whenever the Company issues common or preferred stock, the Operating Partnership issues an equivalent number of units of limited partnership interest of a corresponding class to the Company. Third Amended and Restated 2005 Stock Option and Incentive Plan The Third Amended and Restated 2005 Stock Option and Incentive Plan, or the 2005 Plan, was approved by the Company's board of directors in April 2013 and its stockholders in June 2013 at the Company's annual meeting of stockholders. The 2005 Plan authorizes the issuance of stock options, stock appreciation rights, unrestricted and restricted stock, phantom shares, dividend equivalent rights and other equity-based awards. Subject to adjustments upon certain corporate transactions or events, awards with respect to up to a maximum of 17,130,000 fungible units may be granted under the 2005 Plan. Currently, different types of awards count against the limit on the number of fungible units differently, with (1) full-value awards (i.e., those that deliver the full value of the award upon vesting, such as restricted stock) counting as 2.76 fungible units per share subject to such award (2) stock options, stock appreciation rights and other awards that do not deliver full value and expire five years from the date of grant counting as 0.77 fungible units per share subject to such award and (3) all other awards (e.g., ten -year stock options) counting as 1.0 fungible units per share subject to such award. Awards granted under the 2005 Plan prior to the approval of the second amendment and restatement in June 2010 and third amendment and restatement in June 2013 continue to count against the fungible unit limit based on the ratios that were in effect at the time such awards were granted, which may be different than the current ratios. As a result, depending on the types of awards issued, the 2005 Plan may result in the issuance of more or less than 17,130,000 shares. If a stock option or other award granted under the 2005 Plan expires or terminates, the common stock subject to any portion of the award that expires or terminates without having been exercised or paid, as the case may be, will again become available for the issuance of additional awards. Shares of SL Green's common stock distributed under the 2005 Plan may be treasury shares or authorized but unissued shares. Currently, unless the 2005 Plan has been previously terminated by the Company's board of directors, new awards may be granted under the 2005 Plan until June 13, 2023, which is the tenth anniversary of the date that the 2005 Plan was most recently approved by the Company's stockholders. As of September 30, 2015 , 1.7 million fungible units were available for issuance under the 2005 Plan after reserving for shares underlying outstanding restricted stock units, phantom stock units granted pursuant to our Non-Employee Directors' Deferral Program and LTIP Units, including, among others, outstanding LTIP Units issued under our 2011 Long-Term Outperformance Plan. Options are granted under the plan at the fair market value on the date of grant and, subject to employment, generally expire five or ten years from the date of grant, are not transferable other than on death, and generally vest in one to five years commencing one year from the date of grant. The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option pricing model based on historical information with the following weighted average assumptions for grants during the nine months ended September 30, 2015 and year ended December 31, 2014 . September 30, 2015 December 31, 2014 Dividend yield 1.74 % 1.60 % Expected life of option 3.5 years 3.6 years Risk-free interest rate 1.17 % 1.29 % Expected stock price volatility 34.59 % 33.97 % A summary of the status of the Company's stock options as of September 30, 2015 and December 31, 2014 and changes during the nine months ended September 30, 2015 and the year ended December 31, 2014 are as follows: September 30, 2015 December 31, 2014 Options Outstanding Weighted Average Exercise Price Options Outstanding Weighted Average Exercise Price Balance at beginning of year 1,462,726 $ 87.98 1,765,034 $ 83.24 Granted 40,500 117.50 102,050 119.12 Exercised (170,035 ) 75.33 (348,156 ) 72.76 Lapsed or cancelled (30,417 ) 98.41 (56,202 ) 90.03 Balance at end of period 1,302,774 $ 90.30 1,462,726 $ 87.98 Options exercisable at end of period 594,624 $ 88.44 428,951 $ 90.32 Weighted average fair value of options granted during the period $ 1,112,152 $ 2,841,678 All options were granted with strike prices ranging from $20.67 to $137.18 . The remaining weighted average contractual life of the options outstanding was 3.57 years and the remaining average contractual life of the options exercisable was 3.36 years. During the three and nine months ended September 30, 2015 and 2014, we recognized $1.9 million , $5.8 million . $2.0 million and $6.0 million of compensation expense, respectively, for these options. As of September 30, 2015 , there was $8.8 million of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average period of three years. Stock-based Compensation Effective January 1, 1999, the Company implemented a deferred compensation plan, or the Deferred Plan, where shares issued under the Deferred Plan were granted to certain employees, including our executives and vesting will occur annually upon the completion of a service period or our meeting established financial performance criteria. Annual vesting occurs at rates ranging from 15% to 35% once performance criteria are reached. A summary of the Company's restricted stock as of September 30, 2015 and December 31, 2014 and charges during the nine months ended September 30, 2015 and the year ended December 31, 2014 are as follows: September 30, 2015 December 31, 2014 Balance at beginning of period 3,000,979 2,994,197 Granted 6,053 9,550 Cancelled (3,717 ) (2,768 ) Balance at end of period 3,003,315 3,000,979 Vested during the period 87,081 75,043 Compensation expense recorded $ 5,663,196 $ 9,658,019 Weighted average fair value of restricted stock granted during the period $ 735,011 $ 1,141,675 The fair value of restricted stock that vested during the nine months ended September 30, 2015 and the year ended December 31, 2014 was $7.4 million and $5.5 million , respectively. As of September 30, 2015 , there was $7.4 million of total unrecognized compensation cost related to unvested restricted stock, which is expected to be recognized over a weighted average period of 1.7 years . For the three and nine months ended September 30, 2015 and 2014, $1.5 million , $4.9 million , $1.7 million and $5.2 million , respectively, was capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options. We granted LTIP Units, which include bonus, time-based and performance based awards, with a fair valu e of $25.4 million and $33.2 million as of September 30, 2015 and December 31, 2014, respectively. The grant date fair value of the LTIP Unit awards was calculated in accordance with ASC 718. A third party consultant determined the fair value of the LTIP Units to have a discount from SL Green's common stock price. The discount was calculated by considering the inherent uncertainty that the LTIP Units will reach parity with other common partnership units and the illiquidity due to transfer restrictions. As of September 30, 2015 , there was $4.6 million of total unrecognized compensation expense related to the time-based and performance based awards, which is expected to be recognized over a weighted average period of 1.0 year . During the three and nine months ended September 30, 2015 and 2014 , we recorded compensation expense related to bonus, time-based and performance based awards of $2.7 million , $19.0 million , $3.4 million and $13.7 million , respectively. 2010 Notional Unit Long-Term Compensation Plan In December 2009, the compensation committee of the Company's board of directors approved the general terms of the SL Green Realty Corp. 2010 Notional Unit Long-Term Compensation Program, or the 2010 Long-Term Compensation Plan. The 2010 Long-Term Compensation Plan is a long-term incentive compensation plan pursuant to which award recipients could earn, in the aggregate, from $15.0 million up to $75.0 million of LTIP Units in the Operating Partnership based on the Company's stock price appreciation over three years beginning on December 1, 2009; provided that, if maximum performance had been achieved, $25.0 million of awards could be earned at any time after the beginning of the second year and an additional $25.0 million of awards could be earned at any time after the beginning of the third year. In order to achieve maximum performance under the 2010 Long-Term Compensation Plan, the Company's aggregate stock price appreciation during the performance period had to equal or exceed 50% . The compensation committee determined that maximum performance had been achieved at or shortly after the beginning of each of the second and third years of the performance period and for the full performance period and, accordingly, 366,815 LTIP Units, 385,583 LTIP Units and 327,416 LTIP Units were earned under the 2010 Long-Term Compensation Plan in December 2010, 2011 and 2012, respectively. Substantially in accordance with the original terms of the program, 50% of these LTIP Units vested on December 17, 2012 (accelerated from the original January 1, 2013 vesting date), 25% of these LTIP Units vested on December 11, 2013 (accelerated from the original January 1, 2014 vesting date) and the remainder vested on January 1, 2015 based on continued employment. In accordance with the terms of the 2010 Long-Term Compensation Plan, distributions were not paid on any LTIP Units until they were earned, at which time we paid all distributions that would have been paid on the earned LTIP Units since the beginning of the performance period. The cost of the 2010 Long-Term Compensation Plan ( $31.7 million , subject to forfeitures) was amortized into earnings through the final vesting period of January 1, 2015. We recorded compensation expense of $0.4 million and $2.3 million during the three and nine months ended September 30, 2014 related to the 2010 Long-Term Compensation Plan. 2011 Outperformance Plan In August 2011, the compensation committee of the Company's board of directors approved the general terms of the SL Green Realty Corp. 2011 Outperformance Plan, or the 2011 Outperformance Plan. Participants in the 2011 Outperformance Plan could earn, in the aggregate, up to $85.0 million of LTIP Units in the Operating Partnership based on our total return to stockholders for the three-year period beginning September 1, 2011. Under the 2011 Outperformance Plan, participants were entitled to share in a "performance pool" comprised of LTIP Units with a value equal to 10% of the amount by which our total return to stockholders during the three -year period exceeded a cumulative total return to stockholders of 25% , subject to the maximum of $85.0 million of LTIP Units; provided that if maximum performance was achieved, one-third of each award could be earned at any time after the beginning of the second year and an additional one-third of each award could be earned at any time after the beginning of the third year. LTIP Units earned under the 2011 Outperformance Plan are subject to continued vesting requirements, with 50% of any awards earned vested on August 31, 2014 and the remaining 50% vesting on August 31, 2015, subject to continued employment with us through such dates. Participants were not entitled to distributions with respect to LTIP Units granted under the 2011 Outperformance Plan unless and until they were earned. For LTIP Units that were earned, each participant was also entitled to the distributions that would have been paid had the number of earned LTIP Units been issued at the beginning of the performance period, with such distributions being paid in the form of additional LTIP Units. Thereafter, distributions are to be paid currently with respect to all earned LTIP Units, whether vested or unvested. In June 2014, the compensation committee determined that maximum performance had been achieved during the third year of the performance period and, accordingly, 560,908 LTIP Units, representing two-thirds of each award, were earned, subject to vesting, under the 2011 Outperformance Plan. In September 2014, the compensation committee determined that maximum performance had been achieved for the full three -year performance period and, accordingly, 280,454 LTIP units, representing the final third of each award, were earned, subject to vesting, under the 2011 Outperformance Plan. The cost of the 2011 Outperformance Plan ( $26.7 million , subject to forfeitures) was amortized into earnings through the final vesting period. We recorded compensation expense of $0.6 million , $4.5 million , $1.7 million and $7.8 million during the three and nine months ended September 30, 2015 and 2014, respectively, related to the 2011 Outperformance Plan. 2014 Outperformance Plan In August 2014, the compensation committee of the Company's board of directors approved the general terms of the SL Green Realty Corp. 2014 Outperformance Plan, or the 2014 Outperformance Plan. Participants in the 2014 Outperformance Plan may earn, in the aggregate, up to 610,000 LTIP Units in our Operating Partnership based on our total return to stockholders for the three -year period beginning September 1, 2014. For each individual award, two-thirds of the LTIP Units may be earned based on the Company’s absolute total return to stockholders and one-third of the LTIP Units may be earned based on relative total return to stockholders compared to the constituents of the MSCI REIT Index. Awards earned based on absolute total return to stockholders will be determined independently of awards earned based on relative total return to stockholders. In the event the Company’s performance reaches either threshold before the end of the three -year performance period, a pro-rata portion of the maximum award may be earned. For each component, if the Company’s performance reaches the maximum threshold beginning with the 19th month of the performance period, participants will earn one-third of the maximum award that may be earned for that component. If the Company’s performance reaches the maximum threshold during the third year of the performance period for a component, participants will earn two-thirds (or an additional one-third) of the maximum award that may be earned for that component. LTIP Units earned under the 2014 Outperformance Plan will be subject to continued vesting requirements, with 50% of any awards earned vesting on August 31, 2017 and the remaining 50% vesting on August 31, 2018, subject to continued employment with us through such dates. Participants will not be entitled to distributions with respect to LTIP Units granted under the 2014 Outperformance Plan unless and until they are earned. If LTIP Units are earned, each participant will also be entitled to the distributions that would have been paid had the number of earned LTIP Units been issued at the beginning of the performance period, with such distributions being paid in the form of cash or additional LTIP Units. Thereafter, distributions will be paid currently with respect to all earned LTIP Units, whether vested or unvested. The cost of the 2014 Outperformance Plan ( $27.9 million , subject to forfeitures), based on the portion of the 2014 Outperformance Plan granted as of September 30, 2015 , will be amortized into earnings through the final vesting period. We recorded compensation expense of $ 1.5 million and $4.4 million during the three and nine months ended September 30, 2015 related to the 2014 Outperformance Plan. Deferred Compensation Plan for Directors Under our Non-Employee Director's Deferral Program, which commenced July 2004, the Company's non-employee directors may elect to defer up to 100% of their annual retainer fee, chairman fees, meeting fees and annual stock grant. Unless otherwise elected by a participant, fees deferred under the program shall be credited in the form of phantom stock units. The program provides that a director's phantom stock units generally will be settled in an equal number of shares of common stock upon the earlier of (i) the January 1 coincident with or next following such director's termination of service from the Board of Directors or (ii) a change in control by us, as defined by the program. Phantom stock units are credited to each non-employee director quarterly using the closing price of SL Green's common stock on the first business day of the respective quarter. Each participating non-employee director is also credited with dividend equivalents or phantom stock units based on the dividend rate for each quarter, which are either paid in cash currently or credited to the director’s account as additional phantom stock units. During the nine months ended September 30, 2015 , 8,644 phantom stock units were earned and 5,640 shares of common stock were issued to our board of directors. We recorded compensation expense of $0.1 million , $1.8 million , $0.1 million and $1.5 million during the three and nine months ended September 30, 2015 and 2014 related to the Deferred Compensation Plan. As of September 30, 2015 , there were 84,348 phantom stock units outstanding pursuant to our Non-Employee Director's Deferral Program. Employee Stock Purchase Plan In 2007, the Company's board of directors adopted the 2008 Employee Stock Purchase Plan, or ESPP, to encourage our employees to increase their efforts to make our business more successful by providing equity-based incentives to eligible employees. The ESPP is intended to qualify as an "employee stock purchase plan" under Section 423 of the Code, and has been adopted by the board to enable our eligible employees to purchase the Company's shares of common stock through payroll deductions. The ESPP became effective on January 1, 2008 with a maximum of 500,000 shares of the common stock available for issuance, subject to adjustment upon a merger, reorganization, stock split or other similar corporate change. The Company filed a registration statement on Form S-8 with the SEC with respect to the ESPP. The common stock is offered for purchase through a series of successive offering periods. Each offering period will be three months in duration and will begin on the first day of each calendar quarter, with the first offering period having commenced on January 1, 2008. The ESPP provides for eligible employees to purchase the common stock at a purchase price equal to 85% of the lesser of (1) the market value of the common stock on the first day of the offering period or (2) the market value of the common stock on the last day of the offering period. The ESPP was approved by our stockholders at our 2008 annual meeting of stockholders. As of September 30, 2015 , 85,317 shares of SL Green's common stock had been issued under the ESPP.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss of the Company	9 Months Ended
	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Loss of the Company/Operating Partnership	Stockholders’ Equity of the Company Common Stock Our authorized capital stock consists of 260,000,000 shares, $0.01 par value per share, consisting of 160,000,000 shares of common stock, $0.01 par value per share, 75,000,000 shares of excess stock, at $0.01 par value per share, and 25,000,000 shares of preferred stock, par value $0.01 per share. As of September 30, 2015 , 99,659,376 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In June 2014, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $300.0 million of SL Green's common stock. During the three months ended March 31, 2015, we sold 895,956 shares of our common stock for aggregate net proceeds of $113.4 million comprising the remaining balance of this ATM Program. The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 895,956 units of limited partnership interest of the Operating Partnership. In March 2015, the Company, along with the Operating Partnership, entered into a new ATM Program to sell an aggregate of $300.0 million of SL Green's common stock. During the nine months ended September 30, 2015 , we sold 91,180 shares of our common stock for aggregate net proceeds of $12.0 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 91,180 units of limited partnership interest of the Operating Partnership. As of September 30, 2015 , $288.0 million remained available for issuance of common stock under the new ATM program. Perpetual Preferred Stock We have 9,200,000 shares of our 6.50% Series I Cumulative Redeemable Preferred Stock, or the Series I Preferred Stock, outstanding with a mandatory liquidation preference of $25.00 per share. The Series I Preferred stockholders receive annual dividends of $1.625 per share paid on a quarterly basis and dividends are cumulative, subject to certain provisions. We are entitled to redeem the Series I Preferred Stock at par for cash at our option on or after August 10, 2017. In August 2012, we received $221.9 million in net proceeds from the issuance of the Series I Preferred Stock, which were recorded net of underwriters' discount and issuance costs, and contributed the net proceeds to the Operating Partnership in exchange for 9,200,000 units of 6.50% Series I Cumulative Redeemable Preferred Units of limited partnership interest, or the Series I Preferred Units. Dividend Reinvestment and Stock Purchase Plan In February 2015, the Company filed a registration statement with the SEC for our dividend reinvestment and stock purchase plan, or DRSPP, which automatically became effective upon filing. The Company registered 3,500,000 shares of SL Green's common stock under the DRSPP. The DRSPP commenced on September 24, 2001. During the nine months ended September 30, 2015 , the Company issued 775,529 shares of SL Green's common stock and received net proceeds of $99.5 million of proceeds from dividend reinvestments and/or stock purchases under the DRSPP. DRSPP shares may be issued at a discount to the market price. Earnings per Share SL Green's earnings per share for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic Earnings: Income attributable to SL Green common stockholders $ 163,658 $ 64,688 $ 167,829 $ 446,319 Effect of Dilutive Securities: Redemption of units to common shares 6,468 2,636 6,634 16,010 Diluted Earnings: Income attributable to SL Green common stockholders $ 170,126 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic Shares: Weighted average common stock outstanding 99,621 95,734 99,205 95,437 Effect of Dilutive Securities: Redemption of units to common shares 3,901 3,585 3,924 3,423 Stock-based compensation plans 407 387 480 462 Diluted weighted average common stock outstanding 103,929 99,706 103,609 99,322 SL Green has excluded 263,236 , 233,586 , 231,970 and 769,790 common stock equivalents from the diluted shares outstanding for the three and nine months ended September 30, 2015 and 2014, respectively, as they were anti-dilutive.
SL Green Realty Corp
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Loss of the Company/Operating Partnership	Accumulated Other Comprehensive Loss of the Company The following tables set forth the changes in accumulated other comprehensive income (loss) by component as of September 30, 2015 (in thousands): Net unrealized (loss) gain on derivative instruments ( 1 ) SL Green’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Unrealized gain (loss) on marketable securities Total Balance at December 31, 2014 $ (9,498 ) $ (95 ) $ 2,613 $ (6,980 ) Other comprehensive loss before reclassifications (14,918 ) (2,393 ) (351 ) (17,662 ) Amounts reclassified from accumulated other comprehensive income 7,908 913 — 8,821 Balance at September 30, 2015 $ (16,508 ) $ (1,575 ) $ 2,262 $ (15,821 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of September 30, 2015 and December 31, 2014 , the deferred net losses from these terminated hedges, which is included in accumulated other comprehensive loss relating to net unrealized loss on derivative instrument, was $10.3 million and $11.8 million , respectively. (2) Amount reclassified from accumulated other comprehensive income (loss) is included in equity in net income from unconsolidated joint ventures in the respective consolidated statements of operations.

Accumulated Other Comprehensi27

Accumulated Other Comprehensive Loss of the Operating Partnership	9 Months Ended
	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Loss of the Company/Operating Partnership	Stockholders’ Equity of the Company Common Stock Our authorized capital stock consists of 260,000,000 shares, $0.01 par value per share, consisting of 160,000,000 shares of common stock, $0.01 par value per share, 75,000,000 shares of excess stock, at $0.01 par value per share, and 25,000,000 shares of preferred stock, par value $0.01 per share. As of September 30, 2015 , 99,659,376 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In June 2014, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $300.0 million of SL Green's common stock. During the three months ended March 31, 2015, we sold 895,956 shares of our common stock for aggregate net proceeds of $113.4 million comprising the remaining balance of this ATM Program. The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 895,956 units of limited partnership interest of the Operating Partnership. In March 2015, the Company, along with the Operating Partnership, entered into a new ATM Program to sell an aggregate of $300.0 million of SL Green's common stock. During the nine months ended September 30, 2015 , we sold 91,180 shares of our common stock for aggregate net proceeds of $12.0 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 91,180 units of limited partnership interest of the Operating Partnership. As of September 30, 2015 , $288.0 million remained available for issuance of common stock under the new ATM program. Perpetual Preferred Stock We have 9,200,000 shares of our 6.50% Series I Cumulative Redeemable Preferred Stock, or the Series I Preferred Stock, outstanding with a mandatory liquidation preference of $25.00 per share. The Series I Preferred stockholders receive annual dividends of $1.625 per share paid on a quarterly basis and dividends are cumulative, subject to certain provisions. We are entitled to redeem the Series I Preferred Stock at par for cash at our option on or after August 10, 2017. In August 2012, we received $221.9 million in net proceeds from the issuance of the Series I Preferred Stock, which were recorded net of underwriters' discount and issuance costs, and contributed the net proceeds to the Operating Partnership in exchange for 9,200,000 units of 6.50% Series I Cumulative Redeemable Preferred Units of limited partnership interest, or the Series I Preferred Units. Dividend Reinvestment and Stock Purchase Plan In February 2015, the Company filed a registration statement with the SEC for our dividend reinvestment and stock purchase plan, or DRSPP, which automatically became effective upon filing. The Company registered 3,500,000 shares of SL Green's common stock under the DRSPP. The DRSPP commenced on September 24, 2001. During the nine months ended September 30, 2015 , the Company issued 775,529 shares of SL Green's common stock and received net proceeds of $99.5 million of proceeds from dividend reinvestments and/or stock purchases under the DRSPP. DRSPP shares may be issued at a discount to the market price. Earnings per Share SL Green's earnings per share for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic Earnings: Income attributable to SL Green common stockholders $ 163,658 $ 64,688 $ 167,829 $ 446,319 Effect of Dilutive Securities: Redemption of units to common shares 6,468 2,636 6,634 16,010 Diluted Earnings: Income attributable to SL Green common stockholders $ 170,126 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic Shares: Weighted average common stock outstanding 99,621 95,734 99,205 95,437 Effect of Dilutive Securities: Redemption of units to common shares 3,901 3,585 3,924 3,423 Stock-based compensation plans 407 387 480 462 Diluted weighted average common stock outstanding 103,929 99,706 103,609 99,322 SL Green has excluded 263,236 , 233,586 , 231,970 and 769,790 common stock equivalents from the diluted shares outstanding for the three and nine months ended September 30, 2015 and 2014, respectively, as they were anti-dilutive.
SL Green Operating Partnership
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Loss of the Company/Operating Partnership	Partners' Capital of the Operating Partnership The Company is the sole general partner of the Operating Partnership and at September 30, 2015 owned 99,659,376 general and limited partnership interests in the Operating Partnership and 9,200,000 Series I Preferred Units. Partnership interests in the Operating Partnership are denominated as “common units of limited partnership interest” (also referred to as “OP Units”) or “preferred units of limited partnership interest” (also referred to as “Preferred Units”). All references to OP Units and Preferred Units outstanding exclude such units held by the Company. A holder of an OP Unit may present such OP Unit to the Operating Partnership for redemption at any time (subject to restrictions agreed upon at the issuance of OP Units to particular holders that may restrict such right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, the Operating Partnership must redeem such OP Unit in exchange for the cash equal to the then value of a share of common stock of the Company, except that the Company may, at its election, in lieu of cash redemption, acquire such OP Unit for one share of common stock. Because the number of shares of common stock outstanding at all times equals the number of OP Units that the Company owns, one share of common stock is generally the economic equivalent of one OP Unit, and the quarterly distribution that may be paid to the holder of an OP Unit equals the quarterly dividend that may be paid to the holder of a share of common stock. Each series of Preferred Units makes a distribution that is set in accordance with an amendment to the partnership agreement of the Operating Partnership. Preferred Units may also be convertible into OP Units at the election of the holder thereof or the Company, subject to the terms of such Preferred Units. Net income (loss) allocated to the preferred unitholders and common unitholders reflects their pro rata share of net income (loss) and distributions. Limited Partner Units As of September 30, 2015 , limited partners other than SL Green owned 3.74% , or 3,874,750 common units, of the Operating Partnership. Preferred Units Preferred units not owned by SL Green are further described in Note 11, “Noncontrolling Interests on the Company’s Consolidated Financial Statements - Preferred Units of Limited Partnership Interest in the Operating Partnership.” Earnings per Unit The Operating Partnership's earnings per unit for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic and Diluted Earnings: Income attributable to SLGOP common unitholders $ 170,125 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic units: Weighted average common units outstanding 103,522 99,319 103,129 98,860 Effect of Dilutive Securities: Stock-based compensation plans 407 387 480 462 Diluted weighted average common units outstanding 103,929 99,706 103,609 99,322 The Operating Partnership has excluded 263,236 , 233,586 , 231,970 and 769,790 common unit equivalents from the diluted units outstanding for the three and nine months ended September 30, 2015 and 2014, respectively, as they were anti-dilutive. Accumulated Other Comprehensive Loss of the Operating Partnership The following tables set forth the changes in accumulated other comprehensive income (loss) by component as of September 30, 2015 (in thousands): Net unrealized (loss) gain on derivative instruments ( 1 ) SLGOP’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Unrealized gain (loss) on marketable securities Total Balance at December 31, 2014 $ (9,845 ) $ (100 ) $ 2,689 $ (7,256 ) Other comprehensive loss before reclassifications (15,537 ) (2,486 ) (337 ) (18,360 ) Amounts reclassified from accumulated other comprehensive income 8,221 949 — 9,170 Balance at September 30, 2015 $ (17,161 ) $ (1,637 ) $ 2,352 $ (16,446 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of September 30, 2015 and December 31, 2014, the deferred net losses from these terminated hedges, which is included in accumulated other comprehensive loss relating to net unrealized loss on derivative instrument, was $10.7 million and $12.2 million , respectively. (2) Amount reclassified from accumulated other comprehensive income (loss) is included in equity in net income from unconsolidated joint ventures in the respective consolidated statements of operations.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We are required to disclose fair value information with regard to our financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practical to estimate fair value. The FASB guidance defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. We measure and/or disclose the estimated fair value of financial assets and liabilities based on a hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consist of three broad levels: Level 1 - quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date; Level 2 - inputs other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly; and Level 3 - unobservable inputs for the asset or liability that are used when little or no market data is available. We follow this hierarchy for our assets and liabilities measured at fair value on a recurring and nonrecurring basis. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. Our assessment of the significance of the particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The following tables set forth the assets and liabilities that we measure at fair value on a recurring and non-recurring basis by their levels in the fair value hierarchy at September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 Total Level 1 Level 2 Level 3 Assets: Marketable securities $ 46,432 $ 4,115 $ 42,317 $ — Interest rate cap and swap agreements (included in other assets) $ 7 $ — $ 7 $ — Liabilities: Interest rate cap swap agreements (included in accrued interest payable and other liabilities) $ 18,019 $ — $ 18,019 $ — December 31, 2014 Total Level 1 Level 2 Level 3 Assets: Marketable securities $ 39,429 $ 4,332 $ 35,097 $ — Interest rate swap agreements (included in other assets) $ 2,174 $ — $ 2,174 $ — Liabilities: Interest rate swap agreements (included in accrued interest payable and other liabilities) $ 14,728 $ — $ 14,728 $ — We determine other than temporary impairment in real estate investments and debt and preferred equity investments, including intangibles utilizing cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, which are classified as Level 3 inputs. The marketable securities classified as Level 1 were derived from quoted prices in active markets. The valuation technique used to measure the fair value of the marketable securities classified as Level 2 were valued based on quoted market prices or model driven valuations using the significant inputs derived from or corroborated by observable market data. Marketable securities in an unrealized loss position are not considered to be other than temporarily impaired. We do not intend to sell these securities and it is not more likely than not that we will be required to sell the investments before recovery of their amortized cost bases. The fair value of derivative instruments is based on current market data received from financial sources that trade such instruments and are based on prevailing market data and derived from third party proprietary models based on well-recognized financial principles and reasonable estimates about relevant future market conditions, which are classified as Level 2 inputs. The financial assets and liabilities that are not measured at fair value on our consolidated balance sheets include cash and cash equivalents, restricted cash, accounts receivable, accounts payable and accrued expenses, debt and preferred equity investments, mortgages and other loans payable and other secured and unsecured debt. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, and accounts payable and accrued expenses reported in our consolidated balance sheets approximates fair value due to the short term nature of these instruments. The fair value of debt and preferred equity investments, which is classified as Level 3, is estimated by discounting the future cash flows using current interest rates at which similar loans with the same maturities would be made to borrowers with similar credit ratings. The fair value of borrowings, which is classified as Level 3, is estimated by discounting the contractual cash flows of each debt to their present value using adjusted market interest rates, which is provided by a third-party specialist. The following table provides the carrying value and fair value of these financial instruments as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Carrying Value Fair Value Carrying Value Fair Value Debt and preferred equity investments $ 1,501,619 (1) $ 1,408,804 (1) Fixed rate debt $ 7,137,995 $ 7,610,830 $ 6,140,786 $ 6,565,236 Variable rate debt 2,992,508 3,015,758 2,291,943 2,315,952 $ 10,130,503 $ 10,626,588 $ 8,432,729 $ 8,881,188 ____________________________________________________________________ (1) At September 30, 2015 , debt and preferred equity investments had an estimated fair value ranging between $1.7 billion and $1.9 billion . At December 31, 2014, debt and preferred equity investments had an estimated fair value ranging between $1.5 billion and $1.8 billion . Disclosure about fair value of financial instruments was based on pertinent information available to us as of September 30, 2015 and December 31, 2014. Although we are not aware of any factors that would significantly affect the reasonable fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since that date and current estimates of fair value may differ significantly from the amounts presented herein.

Financial Instruments_ Derivati

Financial Instruments: Derivatives and Hedging	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments: Derivatives and Hedging	Financial Instruments: Derivatives and Hedging In the normal course of business, we use a variety of commonly used derivative instruments, such as interest rate swaps, caps, collar and floors, to manage, or hedge interest rate risk. We hedge our exposure to variability in future cash flows for forecasted transactions in addition to anticipated future interest payments on existing debt. We recognize all derivatives on the balance sheets at fair value. Derivatives that are not hedges are adjusted to fair value through earnings. If a derivative is a hedge, depending on the nature of the hedge, changes in the fair value of the derivative will either be offset against the change in fair value of the hedge asset, liability, or firm commitment through earnings, or recognized in other comprehensive income until the hedged item is recognized in earnings. The ineffective portion of a derivative's change in fair value will be immediately recognized in earnings. Reported net income and equity may increase or decrease prospectively, depending on future levels of interest rates and other variables affecting the fair values of derivative instruments and hedged items, but will have no effect on cash flows. Currently, all of our designated derivative instruments are effective hedging instruments. The following table summarizes the notional value at inception and fair value of our consolidated derivative financial instruments at September 30, 2015 based on Level 2 information. The notional value is an indication of the extent of our involvement in these instruments at that time, but does not represent exposure to credit, interest rate or market risks (amounts in thousands). Notional Value Strike Rate Effective Date Expiration Date Balance Sheet Location Fair Value Interest Rate Cap - Sold $ 504,000 4.750 % May 2014 May 2016 Other Liabilities $ — Interest Rate Cap 504,000 4.750 % May 2014 May 2016 Other Assets — Interest Rate Cap 500,000 4.750 % October 2014 May 2016 Other Liabilities — Interest Rate Cap - Sold 500,000 4.750 % November 2014 May 2016 Other Assets — Interest Rate Cap 446,000 4.750 % October 2014 May 2016 Other Liabilities — Interest Rate Cap 263,426 6.000 % November 2013 November 2015 Other Liabilities — Interest Rate Swap 200,000 0.938 % October 2014 December 2017 Other Liabilities (1,087 ) Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Liabilities (821 ) Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Liabilities (821 ) Interest Rate Swap 144,000 2.236 % December 2012 December 2017 Other Liabilities (4,812 ) Interest Rate Swap 86,400 1.948 % December 2012 December 2017 Other Liabilities (2,345 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (2,522 ) Interest Rate Swap 72,000 1.345 % December 2012 December 2017 Other Liabilities (1,012 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (2,522 ) Interest Rate Swap 57,600 1.990 % December 2012 December 2017 Other Liabilities (1,616 ) Interest Rate Swap 30,000 2.295 % July 2010 June 2016 Other Liabilities (415 ) Interest Rate Swap 14,409 0.500 % January 2015 January 2017 Other Liabilities (7 ) Interest Rate Swap 8,018 0.852 % February 2015 February 2017 Other Liabilities (39 ) Interest Rate Cap 137,500 4.000 % September 2015 September 2017 Other Assets 7 $ (18,012 ) During the three and nine months ended September 30, 2015 , we recorded a gain on the changes in the fair value of $44,000 and $43,000 respectively, which is included in interest expense on the consolidated statements of operations. During the three and nine months ended September 30, 2014 , we recorded a loss on the changes in the fair value of $7,000 and $49,000 , respectively, which is included in interest expense on the consolidated statements of operations. The Company has agreements with each of its derivative counterparties that contain a provision where if the Company either defaults or is capable of being declared in default on any of its indebtedness, then the Company could also be declared in default on its derivative obligations. As of September 30, 2015 , the fair value of derivatives in a net liability position including accrued interest but excluding any adjustment for nonperformance risk related to these agreements was $18.9 million . As of September 30, 2015 , the Company has not posted any collateral related to these agreements and was not in breach of any agreement provisions. If the Company had breached any of these provisions, it could have been required to settle its obligations under the agreements at their aggregate termination value of $18.9 million at September 30, 2015 . Gains and losses on terminated hedges are included in the accumulated other comprehensive loss, and are recognized into earnings over the term of the related mortgage obligation. Over time, the realized and unrealized gains and losses held in accumulated other comprehensive loss will be reclassified into earnings as an adjustment to interest expense in the same periods in which the hedged interest payments affect earnings. We estimate that $8.7 million of the current balance held in accumulated other comprehensive loss will be reclassified into interest expense and $1.0 million of the portion related to our share of joint venture accumulated other comprehensive loss will be reclassified into equity in net income from unconsolidated joint ventures within the next 12 months. The following table presents the effect of our derivative financial instruments and our share of our joint ventures' derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the three months ended September 30, 2015 and 2014, respectively (in thousands): Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion) Location of (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Location of (Loss) or Gain Recognized in Income on Derivative Amount of (Loss) or Gain Recognized into Income (Ineffective Portion) Three Months Ended September 30, Three Months Ended September 30, Three Months Ended September 30, Derivative 2015 2014 2015 2014 2015 2014 Interest Rate Swaps/Caps $ (6,921 ) $ 1,761 Interest expense $ 2,737 $ 1,826 Interest expense $ (31 ) $ 1 Share of unconsolidated joint ventures' derivative instruments (1,526 ) 291 Equity in net income from unconsolidated joint ventures 287 41 Equity in net income from unconsolidated joint ventures (21 ) — $ (8,447 ) $ 2,052 $ 3,024 $ 1,867 $ (52 ) $ 1 The following table presents the effect of our derivative financial instruments and our share of our joint ventures' derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the nine months ended September 30, 2015 and 2014, respectively (in thousands): Amount of (Loss) or Gain Location of(Loss) Reclassified from Accumulated Other Comprehensive Loss into Income Amount of Loss Location of (Loss) or Gain Recognized in Income on Derivative Amount of (Loss) or Gain Nine Months Ended September 30, Nine Months Ended September 30, Nine Months Ended September 30, Derivative 2015 2014 2015 2014 2015 2014 Interest Rate Swaps/Caps $ (15,537 ) $ 1,245 Interest expense $ 8,221 $ 3,790 Interest expense $ (455 ) $ 3 Share of unconsolidated joint ventures' derivative instruments (2,486 ) 4,475 Equity in net income from unconsolidated joint ventures 949 1,870 Equity in net income from unconsolidated joint ventures (21 ) — $ (18,023 ) $ 5,720 $ 9,170 $ 5,660 $ (476 ) $ 3

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings As of September 30, 2015 , the Company and the Operating Partnership were not involved in any material litigation nor, to management's knowledge, was any material litigation threatened against us or our portfolio which if adversely determined could have a material adverse impact on us other than routine litigation arising in the ordinary course of business or litigation that is adequately covered by insurance. Environmental Matters Our management believes that the properties are in compliance in all material respects with applicable Federal, state and local ordinances and regulations regarding environmental issues. Management is not aware of any environmental liability that it believes would have a materially adverse impact on our financial position, results of operations or cash flows. Management is unaware of any instances in which it would incur significant environmental cost if any of our properties were sold. Capital and Ground Leases Arrangements During the three months ended September 30, 2015 , we entered into a ground lease for the land and building located at 30 East 40th Street with a lease term ending in August 2114. Based on our evaluation of the arrangement under ASC 840, land was estimated to be approximately 63.6% of the fair market value of the property. The portion attributable to land was classified as operating lease and the remainder as a capital lease in the amount of $20.0 million . The following is a schedule of future minimum lease payments under capital leases and non-cancellable operating leases with initial terms in excess of one year as of September 30, 2015 (in thousands): Capital lease Non-cancellable operating leases Remaining 2015 $ 560 $ 7,675 2016 2,266 30,816 2017 2,387 31,049 2018 2,387 31,049 2019 2,411 31,066 Thereafter 828,103 795,787 Total minimum lease payments 838,114 $ 927,442 Less amount representing interest (796,943 ) Capital lease obligations $ 41,171

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information The Company is a REIT engaged in all aspects of property ownership and management including investment, leasing operations, capital improvements, development and redevelopment, financing, construction and maintenance in the New York Metropolitan area and have two reportable segments, real estate and debt and preferred equity. We evaluate real estate performance and allocate resources based on earnings contribution to income from continuing operations. The primary sources of revenue are generated from tenant rents and escalations and reimbursement revenue. Real estate property operating expenses consist primarily of security, maintenance, utility costs, real estate taxes and ground rent expense (at certain applicable properties). See Note 5, "Debt and Preferred Equity Investments," for additional details on our debt and preferred equity investments. Selected results of operations for the three and nine months ended September 30, 2015 and 2014, and selected asset information as of September 30, 2015 and December 31, 2014, regarding our operating segments are as follows (in thousands): Real Estate Segment Debt and Preferred Equity Segment Total Company Total revenues Three months ended: September 30, 2015 $ 382,738 $ 49,328 $ 432,066 September 30, 2014 346,305 43,969 390,274 Nine months ended: September 30, 2015 $ 1,100,851 $ 136,588 $ 1,237,439 September 30, 2014 995,584 137,767 1,133,351 (Loss) income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate and purchase price fair value adjustment Three months ended: September 30, 2015 $ (22,486 ) $ 43,480 $ 20,994 September 30, 2014 (10,542 ) 38,098 27,556 Nine months ended: September 30, 2015 $ (81,405 ) $ 114,677 $ 33,272 September 30, 2014 13,148 117,673 130,821 Total assets As of: September 30, 2015 $ 17,966,608 $ 1,523,961 $ 19,490,569 December 31, 2014 15,671,662 1,424,925 17,096,587 Income from continuing operations represents total revenues less total expenses for the real estate segment and total investment income less allocated interest expense for the debt and preferred equity segment. Interest costs for the debt and preferred equity segment are imputed assuming the portfolio is 100% leveraged by our 2012 revolving credit facility and corporate borrowing cost. We also allocate loan loss reserves, net of recoveries, and transaction related costs to the debt and preferred equity segment. We do not allocate marketing, general and administrative expenses (totaling $23.5 million , $72.1 million , $22.6 million and $69.8 million for the three and nine months ended September 30, 2015 and 2014, respectively) to the debt and preferred equity segment since we base performance on the individual segments prior to allocating marketing, general and administrative expenses. All other expenses, except interest, relate entirely to the real estate assets. There were no transactions between the above two segments. The table below reconciles income from continuing operations to net income for the three and nine months ended September 30, 2015 and 2014 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate and purchase price fair value adjustment $ 20,994 $ 27,556 $ 33,272 $ 130,821 Equity in net gain on sale of interest in unconsolidated joint venture/real estate 15,281 16,496 16,050 122,580 Purchase price fair value adjustment — (4,000 ) — 67,446 Gain on sale of real estate 159,704 — 159,704 — Depreciable real estate reserves (19,226 ) — (19,226 ) — Income from continuing operations 176,753 40,052 189,800 320,847 Net income from discontinued operations — 4,035 427 15,449 Gain on sale of discontinued operations — 29,507 12,983 144,242 Net income $ 176,753 $ 73,594 $ 203,210 $ 480,538

Significant Accounting Polici32

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include our accounts and those of our subsidiaries, which are wholly-owned or controlled by us. Entities which we do not control through our voting interest and entities which are variable interest entities, but where we are not the primary beneficiary, are accounted for under the equity method or as debt and preferred equity investments. See Note 5, "Debt and Preferred Equity Investments" and Note 6, "Investments in Unconsolidated Joint Ventures." All significant intercompany balances and transactions have been eliminated. We consolidate a variable interest entity, or VIE, in which we are considered the primary beneficiary. The primary beneficiary is the entity that has (i) the power to direct the activities that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. Included in commercial real estate properties on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 are $198.6 million and $198.4 million , respectively, related to our consolidated VIEs. Included in mortgages and other loans payable on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 are $105.0 million and $106.5 million , respectively, related to our consolidated VIEs. As of September 30, 2015, assets held for sale and liabilities related to assets held for sale on the consolidated balance sheets did not include amounts related to consolidated VIEs. As of December 31, 2014, assets held for sale and liabilities related to assets held for sale on the consolidated balance sheets included $445.0 million of commercial real estate and $253.9 million of mortgage related to the consolidated VIEs. A noncontrolling interest in a consolidated subsidiary is defined as the portion of the equity (net assets) in a subsidiary not attributable, directly or indirectly, to us. Noncontrolling interests are required to be presented as a separate component of equity in the consolidated balance sheet and the presentation of net income is modified to present earnings and other comprehensive income attributed to controlling and noncontrolling interests. We assess the accounting treatment for each joint venture and debt and preferred equity investment. This assessment includes a review of each joint venture or limited liability company agreement to determine which party has what rights and whether those rights are protective or participating. For all VIEs, we review such agreements in order to determine which party has the power to direct the activities that most significantly impact the entity's economic performance. In situations where we and our partner approve, among other things, the annual budget, receive a detailed monthly reporting package, meet on a quarterly basis to review the results of the joint venture, review and approve the joint venture's tax return before filing, and approve all leases that cover more than a nominal amount of space relative to the total rentable space at each property, we do not consolidate the joint venture as we consider these to be substantive participation rights that result in shared power of the activities that most significantly impact the performance of the joint venture. Our joint venture agreements typically contain certain protective rights such as the requirement of partner approval to sell, finance or refinance the property and the payment of capital expenditures and operating expenditures outside of the approved budget or operating plan.
Investment in Commercial Real Estate Properties	Investment in Commercial Real Estate Properties On a periodic basis, we assess whether there are any indications that the value of our real estate properties may be other than temporarily impaired or that their carrying value may not be recoverable. A property's value is considered impaired if management's estimate of the aggregate future cash flows (undiscounted and without interest charges for consolidated properties) to be generated by the property is less than the carrying value of the property. To the extent impairment has occurred, the loss will be measured as the excess of the carrying amount of the property over the calculated fair value of the property. We also evaluate our real estate properties for potential impairment when a real estate property has been classified as held for sale. Real estate assets held for sale are valued at the lower of either their carrying value or fair value less costs to sell. During the three months ended September 30, 2015 , we recorded a $19.2 million charge in connection with the expected sale of two of our properties. This charge is included in depreciable real estate reserves in the consolidated statements of operations. Prior to the quarter ended September 30, 2015, we do not believe that there were any indicators of impairment at these two properties. See Note 4, "Properties Held for Sale and Property Dispositions." Except as noted above, we do not believe that there were any indicators of impairment at any of our consolidated properties at September 30, 2015 . We allocate the purchase price of real estate to land and building (inclusive of tenant improvements) and, if determined to be material, intangibles, such as the value of above- and below-market leases and origination costs associated with the in-place leases. We depreciate the amount allocated to building (inclusive of tenant improvements) over their estimated useful lives, which generally range from three to 40 years . We amortize the amount allocated to the above- and below-market leases over the remaining term of the associated lease, which generally range from one to 14 years, and record it as either an increase (in the case of below-market leases) or a decrease (in the case of above-market leases) to rental income. We amortize the amount allocated to the values associated with in-place leases over the expected term of the associated lease, which generally ranges from one to 14 years. If a tenant vacates its space prior to the contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related intangible will be written off. The tenant improvements and origination costs are amortized as an expense over the remaining life of the lease (or charged against earnings if the lease is terminated prior to its contractual expiration date). We assess fair value of the leases based on estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends, and market/economic conditions that may affect the property. To the extent acquired leases contain fixed rate renewal options that are below-market and determined to be material, we amortize such below-market lease value into rental income over the renewal period.
Fair Value Measurements	Fair Value Measurements We are required to disclose fair value information with regard to our financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practical to estimate fair value. The FASB guidance defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. We measure and/or disclose the estimated fair value of financial assets and liabilities based on a hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity and the reporting entity’s own assumptions about market participant assumptions. This hierarchy consist of three broad levels: Level 1 - quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date; Level 2 - inputs other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly; and Level 3 - unobservable inputs for the asset or liability that are used when little or no market data is available. We follow this hierarchy for our assets and liabilities measured at fair value on a recurring and nonrecurring basis. In instances in which the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level of input that is significant to the fair value measurement in its entirety. Our assessment of the significance of the particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. We determine other than temporary impairment in real estate investments and debt and preferred equity investments, including intangibles utilizing cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, which are classified as Level 3 inputs. The marketable securities classified as Level 1 were derived from quoted prices in active markets. The valuation technique used to measure the fair value of the marketable securities classified as Level 2 were valued based on quoted market prices or model driven valuations using the significant inputs derived from or corroborated by observable market data. Marketable securities in an unrealized loss position are not considered to be other than temporarily impaired. We do not intend to sell these securities and it is not more likely than not that we will be required to sell the investments before recovery of their amortized cost bases. The fair value of derivative instruments is based on current market data received from financial sources that trade such instruments and are based on prevailing market data and derived from third party proprietary models based on well-recognized financial principles and reasonable estimates about relevant future market conditions, which are classified as Level 2 inputs. The financial assets and liabilities that are not measured at fair value on our consolidated balance sheets include cash and cash equivalents, restricted cash, accounts receivable, accounts payable and accrued expenses, debt and preferred equity investments, mortgages and other loans payable and other secured and unsecured debt. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, and accounts payable and accrued expenses reported in our consolidated balance sheets approximates fair value due to the short term nature of these instruments. The fair value of debt and preferred equity investments, which is classified as Level 3, is estimated by discounting the future cash flows using current interest rates at which similar loans with the same maturities would be made to borrowers with similar credit ratings. The fair value of borrowings, which is classified as Level 3, is estimated by discounting the contractual cash flows of each debt to their present value using adjusted market interest rates, which is provided by a third-party specialist.
Investment in Marketable Securities	Investment in Marketable Securities We designate a security as held-to-maturity, available-for-sale, or trading at acquisition. As of September 30, 2015 , we do not have any securities designated as held-to-maturity or trading. We account for our available-for-sale securities at fair value pursuant to Accounting Standards Codification, or ASC, 820-10, with the net unrealized gains or losses reported as a component of accumulated other comprehensive income or loss. Any unrealized losses that are determined to be other-than-temporary are recognized in earnings up to their credit component. The cost of bonds and marketable securities sold is determined using the specific identification method.
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures We assess our investments in unconsolidated joint ventures for recoverability, and if it is determined that a loss in value of the investment is other than temporary, we write down the investment to its fair value. We evaluate our equity investments for impairment based on the joint venture's projected discounted cash flows. We do not believe that the values of any of our equity investments were impaired at September 30, 2015 . We may originate loans for real estate acquisition, development and construction, where we expect to receive some of the residual profit from such projects. When the risk and rewards of these arrangements are essentially the same as an investor or joint venture partner, we account for these arrangements as real estate investments under the equity method of accounting for investments. Otherwise, we account for these arrangements consistent with our loan accounting for our debt and preferred equity investments.
Revenue Recognition	Revenue Recognition Rental revenue is recognized on a straight-line basis over the term of the lease. Rental revenue recognition commences when the tenant takes possession or controls the physical use of the leased space. In order for the tenant to take possession, the leased space must be substantially ready for its intended use. To determine whether the leased space is substantially ready for its intended use, management evaluates whether we are or the tenant is the owner of tenant improvements for accounting purposes. When management concludes that we are the owner of tenant improvements, rental revenue recognition begins when the tenant takes possession of the finished space, which is when such tenant improvements are substantially complete. In certain instances, when management concludes that we are not the owner (the tenant is the owner) of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space. When management concludes that we are the owner of tenant improvements for accounting purposes, we record amounts funded to construct the tenant improvements as a capital asset. For these tenant improvements, we record amounts reimbursed by tenants as a reduction of the capital asset. When management concludes that the tenant is the owner of tenant improvements for accounting purposes, we record our contribution towards those improvements as a lease incentive, which is included in deferred costs, net on our consolidated balance sheets and amortized as a reduction to rental revenue on a straight-line basis over the term of the lease. The excess of rents recognized over amounts contractually due pursuant to the underlying leases are included in deferred rents receivable on the consolidated balance sheets. We establish, on a current basis, an allowance for future potential tenant credit losses, which may occur against this account. The balance reflected on the consolidated balance sheets is net of such allowance. In addition to base rent, our tenants also generally will pay their pro rata share of increases in real estate taxes and operating expenses for the building over a base year. In some leases, in lieu of paying additional rent based upon increases in building operating expenses, the tenant will pay additional rent based upon increases in the wage rate paid to porters over the porters' wage rate in effect during a base year or increases in the consumer price index over the index value in effect during a base year. In addition, many of our leases contain fixed percentage increases over the base rent to cover escalations. Electricity is most often supplied by the landlord either on a sub-metered basis, or rent inclusion basis (i.e., a fixed fee is included in the rent for electricity, which amount may increase based upon increases in electricity rates or increases in electrical usage by the tenant). Base building services other than electricity (such as heat, air conditioning and freight elevator service during business hours, and base building cleaning) are typically provided at no additional cost, with the tenant paying additional rent only for services which exceed base building services or for services which are provided outside normal business hours. These escalations are based on actual expenses incurred in the prior calendar year. If the expenses in the current year are different from those in the prior year, then during the current year, the escalations will be adjusted to reflect the actual expenses for the current year. We record a gain on sale of real estate when title is conveyed to the buyer, subject to the buyer's financial commitment being sufficient to provide economic substance to the sale and we have no substantial economic involvement with the buyer. Interest income on debt and preferred equity investments is accrued based on the outstanding principal amount and contractual terms of the instruments and when, in the opinion of management, it is deemed collectible. Several of the debt and preferred equity investments provide for accrual of interest at specified rates, which differ from current payment terms. Interest is recognized on such loans at the accrual rate subject to management's determination that accrued interest is ultimately collectible, based on the underlying collateral and operations of the borrower. If management cannot make this determination, interest income above the current pay rate is recognized only upon actual receipt. Deferred origination fees, original issue discounts and loan origination costs, if any, are recognized as a reduction to the interest income over the terms of the related investments using the effective interest method. Fees received in connection with loan commitments are also deferred until the loan is funded and are then recognized over the term of the loan as an adjustment to yield. Discounts or premiums associated with the purchase of loans are amortized or accreted into interest income as a yield adjustment on the effective interest method based on expected cashflows through the expected maturity date of the related investment. If we purchase a debt or preferred equity investment at a discount, intend to hold it until maturity and expect to recover the full value of the investment, we accrete the discount into income as an adjustment to yield over the term of the investment. If we purchase a debt or preferred equity investment at a discount with the intention of foreclosing on the collateral, we do not accrete the discount. For debt investments acquired at a discount for credit quality, the difference between contractual cash flows and expected cash flows at acquisition is not accreted. Anticipated exit fees, the collection of which is expected, are also recognized over the term of the loan as an adjustment to yield. Debt and preferred equity investments are placed on a non-accrual status at the earlier of the date at which payments become 90 days past due or when, in the opinion of management, a full recovery of interest income becomes doubtful. Interest income recognition on any non-accrual debt or preferred equity investment is resumed when such non-accrual debt or preferred equity investment becomes contractually current and performance is demonstrated to be resumed. Interest is recorded as income on impaired loans only to the extent cash is received. We may syndicate a portion of the loans that we originate or sell these loans individually. When a transaction meets the criteria of sale accounting, we derecognize the loan sold and recognize gain or loss based on the difference between the sales price and the carrying value of the loan sold. Any related unamortized deferred origination fees, original issue discounts, loan origination costs, discounts or premiums at the time of sale are recognized as an adjustment to the gain or loss on sale, which is included in investment income on the consolidated statement of income. Any fees received at the time of sale or syndication are recognized as part of investment income. Asset management fees are recognized on a straight-line basis over the term of the asset management agreement.
Reserve for Possible Credit Losses	Reserve for Possible Credit Losses The expense for possible credit losses in connection with debt and preferred equity investments is the charge to earnings to increase the allowance for possible credit losses to the level that we estimate to be adequate, based on Level 3 data, considering delinquencies, loss experience and collateral quality. Other factors considered relate to geographic trends and product diversification, the size of the portfolio and current economic conditions. Based upon these factors, we establish the provision for possible credit losses on each individual investment. When it is probable that we will be unable to collect all amounts contractually due, the investment is considered impaired. Where impairment is indicated on an investment that is held to maturity, a valuation allowance is measured based upon the excess of the recorded investment amount over the net fair value of the collateral. Any deficiency between the carrying amount of an asset and the calculated value of the collateral is charged to expense. We continue to assess or adjust our estimates based on circumstances of a loan and the underlying collateral. If the additional information obtained reflects increased recovery of our investment, we will adjust our reserves accordingly. There were no loan reserves recorded during three and nine months ended September 30, 2015 and 2014 . Debt and preferred equity investments held for sale are carried at the lower of cost or fair market value using available market information obtained through consultation with dealers or other originators of such investments as well as discounted cash flow models based on Level 3 data pursuant to ASC 820-10. As circumstances change, management may conclude not to sell an investment designated as held for sale. In such situations, the investment will be reclassified at its net carrying value to debt and preferred equity investments held to maturity. For these reclassified investments, the difference between the current carrying value and the expected cash to be collected at maturity will be accreted into income over the remaining term of the investment.
Income Taxes	Income Taxes SL Green is taxed as a REIT under Section 856(c) of the Code. As a REIT, SL Green generally is not subject to Federal income tax. To maintain its qualification as a REIT, SL Green must distribute at least 90% of its REIT taxable income to its stockholders and meet certain other requirements. If SL Green fails to qualify as a REIT in any taxable year, SL Green will be subject to Federal income tax on SL Green's taxable income at regular corporate rates. SL Green may also be subject to certain state, local and franchise taxes. Under certain circumstances, Federal income and excise taxes may be due on SL Green's undistributed taxable income. The Operating Partnership is a partnership and, as a result, all income and losses of the partnership are allocated to the partners for inclusion in their respective income tax returns. The only provision for income taxes included in the consolidated statements of operations relates to the Operating Partnership’s consolidated taxable REIT subsidiaries. The Operating Partnership may also be subject to certain state, local and franchise taxes. Pursuant to amendments to the Code that became effective January 1, 2001, we have elected, and may elect in the future, to treat certain of our existing or newly created corporate subsidiaries as taxable REIT subsidiaries, or TRSs. In general, TRSs may perform non-customary services for the tenants of the Company, hold assets that we cannot hold directly and generally may engage in any real estate or non-real estate related business. The TRSs generate income, resulting in Federal and state income tax liability for these entities. During the three and nine months ended September 30, 2015 and 2014 , we recorded Federal, state and local tax provisions of $1.1 million , $2.5 million , $1.6 million and $6.6 million , respectively. We follow a two-step approach for evaluating uncertain tax positions. Recognition (step one) occurs when an enterprise concludes that a tax position, based solely on its technical merits, is more-likely-than-not to be sustained upon examination. Measurement (step two) determines the amount of benefit that is more-likely-than-not to be realized upon settlement. Derecognition of a tax position that was previously recognized would occur when a company subsequently determines that a tax position no longer meets the more-likely-than-not threshold of being sustained. The use of a valuation allowance as a substitute for derecognition of tax positions is prohibited.
Stock-Based Employee Compensation Plans	Stock-Based Employee Compensation Plans We have a stock-based employee compensation plan, described more fully in Note 14, "Share-based Compensation." The Company's stock options are recorded at fair value at the time of issuance. Fair value of the stock options is determined using the Black-Scholes option pricing model. The Black-Scholes model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of highly subjective assumptions including the expected stock price volatility. Because our plan has characteristics significantly different from those of traded options and because changes in the subjective input assumptions can materially affect the fair value estimate, in our opinion, the existing models do not necessarily provide a reliable single measure of the fair value of the employee stock options. Compensation cost for stock options, if any, is recognized over the vesting period of the award. Our policy is to grant options with an exercise price equal to the quoted closing market price of the Company's common stock on the grant date. Awards of stock or restricted stock are expensed as compensation over the benefit period based on the fair value of the stock on the grant date. For share-based awards with a performance or market measure, we recognize compensation cost over the requisite service period, using the accelerated attribution expense method. The requisite service period begins on the date the compensation committee of SL Green's board of directors authorizes the award, adopts any relevant performance measures and communicates the award to the employees. For programs with awards that vest based on the achievement of a performance condition or market condition, we determine whether it is probable that the performance condition will be met, and estimate compensation cost based on the fair value of the award at the applicable reporting date estimated using a binomial model or market quotes. For share-based awards for which there is no pre-established performance measure, we recognize compensation cost over the service vesting period, which represents the requisite service period, on a straight-line basis. In accordance with the provisions of our share-based incentive compensation plans, we accept the return of shares of the Company's common stock, at the current quoted market price, from certain key employees to satisfy minimum statutory tax-withholding requirements related to shares that vested during the period. Awards can also be made in the form of a separate series of units of limited partnership interest in the Operating Partnership called long-term incentive plan units, or LTIP units. LTIP units, which can be granted either as free-standing awards or in tandem with other awards under our stock incentive plan, are valued by reference to the value of the Company's common stock at the time of grant, and are subject to such conditions and restrictions as the compensation committee of the Company's board of directors may determine, including continued employment or service, computation of financial metrics and/or achievement of pre-established performance goals and objectives.
Earnings per Share of the Company	Earnings per Share of the Company The Company presents both basic and diluted earnings per share, or EPS. Basic EPS excludes dilution and is computed by dividing net income or loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Basic EPS includes participating securities, consisting of unvested restricted stock that receive nonforfeitable dividends similar to shares of common stock. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, where such exercise or conversion would result in a lower EPS amount. Diluted EPS also includes units of limited partnership interest. The dilutive effect of stock options is reflected in the weighted average diluted outstanding shares calculation by application of the treasury stock method. There is no dilutive effect for the exchangeable senior notes as the conversion premium will be paid in cash.
Earnings per Unit of the Operating Partnership	Earnings per Unit of the Operating Partnership The Operating Partnership presents both basic and diluted earnings per unit, or EPU. Basic EPU excludes dilution and is computed by dividing net income or loss attributable to common unitholders by the weighted average number of common units outstanding during the period. Basic EPU includes participating securities, consisting of unvested restricted units that receive nonforfeitable dividends similar to shares of common units. Diluted EPU reflects the potential dilution that could occur if securities or other contracts to issue common units were exercised or converted into common units, where such exercise or conversion would result in a lower EPU amount. The dilutive effect of unit options is reflected in the weighted average diluted outstanding units calculation by application of the treasury stock method. There is no dilutive effect for the exchangeable senior notes as the conversion premium will be paid in cash.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash investments, debt and preferred equity investments and accounts receivable. We place our cash investments in excess of insured amounts with high quality financial institutions. The collateral securing our debt and preferred equity investments is located in New York City. See Note 5, "Debt and Preferred Equity Investments." We perform ongoing credit evaluations of our tenants and require most tenants to provide security deposits or letters of credit. Though these security deposits and letters of credit are insufficient to meet the total value of a tenant's lease obligation, they are a measure of good faith and a source of funds to offset the economic costs associated with lost rent and the costs associated with re-tenanting a space. Although the properties in our real estate portfolio are primarily located in Manhattan, we also have properties located in Brooklyn, Long Island, Westchester County, Connecticut and New Jersey. The tenants located in our buildings operate in various industries.
Reclassification	Reclassification Certain prior year balances have been reclassified to conform to our current year presentation primarily in order to eliminate discontinued operations from income from continuing operations.
Accounting Standards Updates	Accounting Standards Updates In September 2015, the Financial Accounting Standards Board, or FASB, issued final guidance to simplify the measurement-period adjustments in business combinations (Accounting Standards Update, or ASU, No. 2015-62). The guidance eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, acquirers must recognize measurement-period adjustments in the period in which they determine the amounts, including the effect on earnings of any amounts they would have recorded in previously periods if the accounting had been completed at the acquisition date. The guidance is effective for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the guidance is permitted. The Company adopted the guidance during the third quarter of 2015. In April 2015, the FASB issued final guidance to simplify the presentation of debt issuance costs by requiring debt issuance costs to be presented as a deduction from the corresponding debt liability (ASU No. 2015-03). The guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. The guidance is effective for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the guidance is permitted. Upon adoption, an entity must apply the new guidance retrospectively for all prior periods presented in the financial statements. The Company expects to adopt the guidance effective January 1, 2016 and the guidance is not anticipated to have a material impact on our consolidated financial statements. In February 2015, the FASB issued new guidance that amends the current consolidation guidance, including introducing a separate consolidation analysis specific to limited partnerships and other similar entities (ASU No. 2015-02). Under this analysis, limited partnerships and other similar entities will be considered a VIE unless the limited partners hold substantive kick-out rights or participating rights. The guidance is effective for annual and interim periods beginning after December 15, 2015. Early adoption of this guidance is permitted. The Company is currently evaluating the new guidance to determine the impact it may have on our consolidated financial statements. In June 2014, the FASB issued final guidance that requires repurchase-to-maturity transactions to be accounted for as secured borrowings as if the transferor retains effective control, even though the transferred financial assets are not returned to the transferor at settlement and also eliminates existing guidance for repurchase financings (ASU No. 2014-11). New disclosures are required for (1) certain transactions accounted for as secured borrowings and (2) transfers accounted for as sales when the transferor also retains substantially all of the exposure to the economic return on the transferred financial assets throughout the term of the transaction. The guidance was effective for the first interim or annual period beginning after December 15, 2014, except for the disclosures related to transactions accounted for as secured borrowings, which are effective for periods beginning after March 15, 2015. Early adoption of this guidance is prohibited. The Company adopted the standard beginning in the first quarter of 2015. The adoption of this guidance did not have a material impact on our consolidated financial statements. The Company has adopted the presentation and disclosures related to transactions accounted for as secured borrowings during the second quarter of 2015. In May 2014, the FASB issued a new comprehensive revenue recognition guidance which requires us to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods and services (ASU No. 2014-09). The guidance also requires enhanced disclosures to help users of financial statements better understand the nature, amount, timing, and uncertainty of revenue that is recognized. The guidance is effective for annual and interim periods beginning after December 15, 2016 and early adoption is not permitted. In July 2015, the FASB voted to defer by one year the effective date of ASU 2014-09 for both public and nonpublic entities and give both public and private companies the option to early adopt using the original effective date. The new guidance can be applied either retrospectively to each prior reporting period presented, or as a cumulative-effect adjustment as of the date of adoption. The Company is currently evaluating the new guidance to determine the impact it may have on our consolidated financial statements. In April 2014, the FASB issued new guidance on reporting discontinued operations which raises the threshold for disposals to qualify as discontinued operations (ASU No. 2014-08). The guidance also allows us to have a significant continuing involvement and continuing cash flows with the discontinued operations. Additionally, the guidance requires additional disclosures for discontinued operations and new disclosures for individually material disposal transactions that do not meet the definition of a discontinued operation. The guidance was effective for calendar year public companies beginning in the first quarter of 2015 and is to be applied on a prospective basis for new disposals. Early adoption of this guidance was permitted. The Company adopted the standard beginning in the first quarter of 2015. The adoption of this guidance will change the presentation of discontinued operations for all properties held for sale and/or disposed of subsequent to January 1, 2015.

Organization and Basis of Pre33

Organization and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of commercial office properties	As of September 30, 2015 , we owned the following interests in commercial and residential properties in the New York Metropolitan area, primarily in midtown Manhattan. Our investments in the New York Metropolitan area also include investments in Brooklyn, Long Island, Westchester County, Connecticut and New Jersey, which are collectively known as the Suburban properties: Consolidated Unconsolidated Total Location Type Number of Properties Approximate Square Feet Number of Properties Approximate Square Feet Number of Properties Approximate Square Feet Weighted Average Occupancy (1) Commercial: Manhattan Office 26 20,700,091 6 3,328,496 32 24,028,587 94.5 % Retail 9 (3) 408,993 9 347,970 18 756,963 91.2 % Development/Redevelopment (2) 5 72,962 4 1,952,782 9 2,025,744 53.8 % Fee Interest 2 783,530 — — 2 783,530 100.0 % 42 21,965,576 19 5,629,248 61 27,594,824 91.5 % Suburban Office (2) 28 4,450,400 3 705,641 31 5,156,041 80.1 % Retail 1 52,000 — — 1 52,000 100.0 % Development/Redevelopment 1 1,000 1 — 2 1,000 100.0 % 30 4,503,400 4 705,641 34 5,209,041 80.3 % Total commercial properties 72 26,468,976 23 6,334,889 95 32,803,865 89.8 % Residential: Manhattan Residential 4 (3) 762,587 18 2,210,233 22 2,972,820 94.6 % Suburban Residential 1 66,611 — — 1 66,611 95.8 % Total residential properties 5 829,198 18 2,210,233 23 3,039,431 94.6 % Total portfolio 77 27,298,174 41 8,545,122 118 35,843,296 90.2 % ____________________________________________________________________ (1) The weighted average occupancy for commercial properties represents the total occupied square feet divided by total available rentable square feet. The weighted average occupancy for residential properties represents the total occupied units divided by total available units. (2) Includes two Manhattan redevelopment properties and two suburban office properties held for sale as of September 30, 2015. (3) As of September 30, 2015 , we owned a building that was comprised of approximately 270,132 square feet of retail space and approximately 222,855 square feet of residential space. For the purpose of this report, we have included the building in the retail properties count and have bifurcated the square footage into the retail and residential components.

Significant Accounting Polici34

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases)	The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Identified intangible assets (included in other assets): Gross amount $ 939,518 $ 664,297 Accumulated amortization (392,854 ) (383,236 ) Net (1) $ 546,664 $ 281,061 Identified intangible liabilities (included in deferred revenue): Gross amount $ 866,561 $ 655,755 Accumulated amortization (476,272 ) (483,948 ) Net (1) $ 390,289 $ 171,807 ____________________________________________________________________ (1) As of September 30, 2015, $0.2 million and $0.1 million of net intangible assets and net intangible liabilities, respectively, were reclassed to assets held for sale and liabilities related to assets held for sale.
Schedule of marketable securities	At September 30, 2015 and December 31, 2014 , we held the following marketable securities (in thousands): September 30, 2015 December 31, 2014 Equity marketable securities $ 4,115 $ 4,332 Mortgage-backed securities 42,317 35,097 Total marketable securities available-for-sale $ 46,432 $ 39,429

Property Acquisitions (Tables)

Property Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2015
Property Acquisitions
Summary of Unaudited Pro Forma Basis Results of Operations	The following table summarizes, on an unaudited pro forma basis, the results of operations of 11 Madison Avenue, which are included in the consolidated statements of operations, and our consolidated results of operations for the three and nine months ended September 30, 2015 and 2014 as though the acquisition of 11 Madison Avenue was completed on January 1, 2014. The supplemental pro forma data is not necessarily indicative of what the actual results of operations would have been assuming the transactions had been completed as set forth above, nor do they purport to represent our results of operations for future periods. Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2015 2014 2015 2014 Actual revenues since acquisition $ 9,051 $ 9,051 Actual net income since acquisition (4,202 ) (4,202 ) Pro forma revenues 432,822 397,684 1,255,507 1,146,697 Pro forma income from continuing operations 25,299 31,197 26,645 350,125 Pro forma basic earnings per share $ 0.18 $ 0.59 $ 0.11 $ 6.39 Pro forma diluted earnings per share $ 0.18 $ 0.59 $ 0.11 $ 6.36 Pro forma basic earnings per unit $ 0.18 $ 0.59 $ 0.11 $ 6.39 Pro forma diluted earnings per unit $ 0.18 $ 0.59 $ 0.11 $ 6.36 ______________________________________________________________________ (1) The pro forma income from continuing operations for the three and nine months ended September 30, 2015 and 2014 includes the effect of the incremental borrowings, including a $1.4 billion , 10 -year, interest only, fixed rate mortgage financing carrying a per annum stated interest rate of 3.838% to complete the acquisition and the preliminary allocation of purchase price. In addition, the pro forma net income for the nine months ended September 30, 2014 was adjusted to include the sale of real estate assets for properties that have closed either subsequent to June 30, 2015 or we are currently under contract to sell, as if the sales were completed on January 1, 2014. The pro forma net income for the three and nine months ended September 30, 2015 excludes these sales.
Schedule of Fair Value of Equity Interest Immediately Before Acquisition Date	The acquisition-date fair value of the equity interest in 388-390 Greenwich Street immediately before the acquisition date as well as the purchase price fair value, as determined in accordance with the methodology set out in the prior sentence, is as follows (in thousands): 388-390 Greenwich Street Contract purchase price $ 1,585,000 Net consideration funded by us at closing, excluding consideration financed by debt (208,614 ) Debt assumed (1,162,379 ) Fair value of retained equity interest 214,007 Equity and/or debt investment held (148,025 ) Other (1) 5,464 Purchase price fair value adjustment $ 71,446 ___________________________________________________________________ (1) Includes the acceleration of a deferred leasing commission from the joint venture to the Company.
2015 Acquisitions
Property Acquisitions
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following summarizes our preliminary allocation of the purchase price of the assets acquired and liabilities assumed upon the closing of these acquisitions (in thousands): 187 Broadway and 5 & 7 Dey Street (1)(2) 11 Madison Avenue (1)(3) 110 Greene Street (1)(4) Upper East Side Residential (1)(5) 1640 Flatbush Avenue (1) Acquisition Date August 2015 August 2015 July 2015 June 2015 March 2015 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Property Type Residential/Retail Office Office Residential/Retail Retail Purchase Price Allocation: Land $ 22,101 $ 849,926 $ 89,250 $ 17,500 $ 6,120 Building and building leasehold 41,045 1,579,118 165,750 32,500 680 Above-market lease value — — — — — Acquired in-place leases — — — — — Other assets, net of other liabilities — — — — — Assets acquired 63,146 2,429,044 255,000 50,000 6,800 Mark-to-market assumed debt — — — — — Below-market lease value — — — — — Derivatives — — — — — Liabilities assumed — — — — — Purchase price $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Net consideration funded by us at closing, excluding consideration financed by debt $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Equity and/or debt investment held $ — $ — $ — $ — $ — Debt assumed $ — $ — $ — $ — $ — ____________________________________________________________________ (1) We are currently in the process of analyzing the purchase price allocation and, as such, we have not allocated any value to intangible assets such as above- and below-market lease or in-place leases. (2) We acquired this property for consideration that included the issuance of $10.0 million and $26.9 million aggregate liquidation preferences of Series R and S Preferred Units, respectively, of limited partnership interest of the Operating Partnership and cash. (3) In August 2015, we acquired this property from a partnership of the Sapir Organization and CIM Group, with whom we have no other relationship. (4) We acquired a 90.0% controlling interest in this property for consideration that included the issuance of $5.0 million and $6.7 million aggregate liquidation preferences of Series P and Q Preferred Units, respectively, of limited partnership interest of the Operating Partnership and cash. (5) We, along with our joint venture partner, acquired this property for consideration that included the issuance of $13.8 million aggregate liquidation preference of Series N Preferred Units of limited partnership interest of the Operating Partnership and cash. We hold a 95.1% controlling interest in this joint venture.
2014 Acquisitions
Property Acquisitions
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	During the nine months ended September 30, 2015 , we finalized the purchase price allocations based on third party appraisal and additional facts and circumstances that existed at the acquisition dates for the following 2014 acquisitions (in thousands): 102 Greene Street (1) 635 Madison Avenue (1) 719 Seventh Avenue (1)(2) 115 Spring Street (1) 388-390 Greenwich Street (1)(3) Acquisition Date October 2014 September 2014 July 2014 July 2014 May 2014 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Property Type Retail Land Development Retail Office Purchase Price Allocation: Land $ 8,215 $ 205,632 $ 41,850 $ 11,078 $ 516,292 Building and building leasehold 26,717 15,805 — 44,799 964,434 Above-market lease value — — — — — Acquired in-place leases 1,015 17,345 — 2,037 302,430 Other assets, net of other liabilities 3 — — — 6,495 Assets acquired 35,950 238,782 41,850 57,914 1,789,651 Mark-to-market assumed debt — — — — — Below-market lease value 3,701 85,036 — 4,789 186,782 Derivatives — — — — 18,001 Liabilities assumed 3,701 85,036 — 4,789 204,783 Purchase price $ 32,249 $ 153,746 $ 41,850 $ 53,125 $ 1,584,868 Net consideration funded by us at closing, excluding consideration financed by debt $ 32,249 $ 153,746 $ 41,850 $ 53,125 $ 208,614 Equity and/or debt investment held $ — $ — $ — $ — $ 148,025 Debt assumed $ — $ — $ — $ — $ 1,162,379 ____________________________________________________________________ (1) Based on our preliminary analysis of the purchase price, we had allocated $11.3 million and $21.0 million to land and building, respectively, at 102 Greene Street, $153.7 million to land at 635 Madison Avenue, $14.4 million and $26.7 million to land and building, respectively, at 719 Seventh Avenue, $15.9 million and $37.2 million to land and building, respectively, at 115 Spring Street and $558.7 million and $1.0 billion to land and building, respectively, at 388-390 Greenwich. The impact to our consolidated statement of income for the nine months ended September 30, 2015 was $7.6 million in rental revenue for the amortization of aggregate below-market leases and $10.3 million of depreciation expense. (2) We, along with our joint venture partner, acquired this property for consideration that included the issuance of $14.1 million aggregate liquidation preference of Series L Preferred Units of limited partnership interest of the Operating Partnership and $9.5 million aggregate liquidation preference of Series K Preferred Units of limited partnership interest of the Operating Partnership. We hold a 75.0% controlling interest in this joint venture. (3) In May 2014, we acquired Ivanhoe Cambridge, Inc.'s 49.65% economic interest in this property, thereby consolidating full ownership of the property. The transaction valued the consolidated interests at $1.585 billion . Simultaneous with the closing, we refinanced the previous mortgage with a $1.45 billion mortgage. We also assumed the existing derivative instruments, which swapped $504.0 million of the mortgage to fixed rate (in October 2014, we entered into multiple swap agreements to hedge our interest rate exposure on an additional $500.0 million portion of this mortgage. See Note 8, "Mortgages and Other Loans Payable" for further details). We recognized a purchase price fair value adjustment of $71.4 million upon closing of this transaction. This property, which we initially acquired in December 2007, was previously accounted for as an investment in unconsolidated joint ventures.

Properties Held for Sale and 36

Properties Held for Sale and Property Dispositions (Tables)	9 Months Ended
	Sep. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Summary of properties sold and income from discontinued operations	The following table summarizes the properties sold during the nine months ended September 30, 2015 : Property Disposition Date Property Type Approximate Usable Square Feet Sales Price (1) (in millions) Gain on Sale (2) (in millions) 180 Maiden Lane January 2015 Office 1,090,000 $ 470.0 $ 17.0 131-137 Spring Street (3) August 2015 Office 68,342 277.8 101.1 120 West 45th Street September 2015 Office 440,000 365.0 58.6 ____________________________________________________________________ (1) Sales price represents the actual sales price for a property or the gross asset valuation for interests in a property. (2) The gain on sale for 180 Maiden Lane, 131-137 Spring Street, and 120 West 45th Street are net of employee compensation awards accrued in connection with the realization of these investment gains as a bonus to certain employees that were instrumental in realizing the gain on sale. Additionally, amounts do not include adjustments for expenses recorded in subsequent periods. (3) We sold an 80% interest in 131-137 Spring Street and have subsequently accounted for our interest in the properties as an investment in unconsolidated joint ventures. See Note 6, "Investments in Unconsolidated Joint Ventures." The following table summarizes net income from discontinued operations for the three and nine months ended September 30, 2015 and 2014 , respectively (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Revenues Rental revenue $ — $ 9,504 $ 236 $ 44,676 Escalation and reimbursement revenues — (194 ) (127 ) 4,413 Other income — — — 21 Total revenues — 9,310 109 49,110 Operating expenses — 773 (631 ) 7,101 Real estate taxes — 787 250 6,618 Ground rent — — — 3,001 Transaction related costs — 115 (49 ) 155 Interest expense, net of interest income — 2,874 109 10,983 Amortization of deferred financing costs — 48 3 369 Depreciation and amortization — 678 — 5,434 Total expenses — 5,275 (318 ) 33,661 Net income from discontinued operations $ — $ 4,035 $ 427 $ 15,449

Debt and Preferred Equity Inv37

Debt and Preferred Equity Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of debt investments	As of September 30, 2015 and December 31, 2014, we held the following debt investments with an aggregate weighted average current yield of 10.32% at September 30, 2015 (in thousands): Loan Type September 30, 2015 Future Funding Obligations September 30, 2015 Senior Financing September 30, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Fixed Rate Investments: Jr. Mortgage Participation $ — $ 205,000 $ 72,541 $ 70,688 February 2016 Jr. Mortgage Participation/Mezzanine Loan (2)(3) — — 23,371 45,611 May 2016 Jr. Mortgage Participation — 133,000 49,000 49,000 June 2016 Mezzanine Loan — 165,000 72,031 71,656 November 2016 Jr. Mortgage Participation/Mezzanine Loan — 1,109,000 102,709 98,934 March 2017 Mezzanine Loan (3) — — 66,075 65,770 March 2017 Mezzanine Loan (4) 155 502,100 40,938 24,608 June 2017 Mezzanine Loan — 539,000 49,666 49,629 July 2018 Mortgage Loan (5) — — 26,249 26,209 February 2019 Mortgage Loan — — 545 637 August 2019 Loan Type September 30, 2015 Future Funding Obligations September 30, 2015 Senior Financing September 30, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Mezzanine Loan — 15,000 3,500 3,500 September 2021 Mezzanine Loan (6) — 90,000 19,934 19,930 November 2023 Mezzanine Loan — 95,000 30,000 30,000 January 2025 Mezzanine Loan (7) — — — 14,068 Jr. Mortgage Participation (8) — — — 11,934 Total fixed rate $ 155 $ 2,853,100 $ 556,559 $ 582,174 Floating Rate Investments: Mezzanine Loan — 775,000 74,349 73,402 March 2016 Mortgage/Mezzanine Loan 14,981 — 81,730 — April 2016 Mezzanine Loan (9) — 160,000 22,612 22,573 June 2016 Jr. Mortgage Participation — 30,000 15,000 — July 2016 Mezzanine Loan — 115,000 24,914 24,910 July 2016 Mezzanine Loan (10) — 110,000 50,000 49,614 September 2016 Mezzanine Loan — 360,000 99,398 99,023 November 2016 Mezzanine Loan 9,726 304,610 64,430 — November 2016 Mezzanine Loan (11) 12,885 127,824 48,226 42,750 December 2016 Mezzanine Loan 461 38,687 13,539 11,835 December 2016 Mortgage/Mezzanine Loan (12) 66,314 — 124,789 — January 2017 Mezzanine Loan 1,851 118,718 27,956 20,651 January 2017 Jr. Mortgage Participation/Mezzanine Loan 1,508 117,460 40,034 38,524 July 2017 Mortgage/Mezzanine Loan — — 22,858 22,803 July 2017 Mortgage/Mezzanine Loan — — 16,887 16,848 September 2017 Mezzanine Loan — 60,000 14,892 14,859 November 2017 Mortgage/Mezzanine Loan (13) 795 — 14,917 14,845 December 2017 Jr. Mortgage Participation — 40,000 19,830 — April 2018 Mezzanine Loan — 350,000 34,698 — April 2018 Jr. Mortgage Participation/Mezzanine Loan — 55,000 20,516 20,533 July 2018 Mortgage/Mezzanine Loan 1,500 — 31,185 — August 2018 Mortgage/Mezzanine Loan — — 18,316 18,083 February 2019 Mezzanine Loan — 38,000 21,835 21,807 March 2019 Mezzanine Loan (14) — — — 33,726 Mezzanine Loan (14) — — — 37,322 Mortgage/Mezzanine Loan (15) — — — 109,527 Total floating rate $ 110,021 $ 2,800,299 $ 902,911 $ 693,635 Total $ 110,176 $ 5,653,399 $ 1,459,470 $ 1,275,809 ____________________________________________________________________ (1) Carrying value is net of discounts, premiums, original issue discounts and deferred origination fees. (2) The $22.9 million junior mortgage participation, which matures in February 2016, was sold in July 2015. (3) These loans are collateralized by defeasance securities. (4) Carrying value is net of $41.3 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (5) In September 2014, we acquired a $26.4 million mortgage loan at a $0.2 million discount and a $5.7 million junior mortgage participation at a $5.7 million discount. The junior mortgage participation was a nonperforming loan at acquisition and is currently on non-accrual status. (6) Carrying value is net of $5.0 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (7) This loan was repaid in February 2015. (8) This loan was repaid in March 2015. (9) Carrying value is net of $7.4 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (10) In August 2015, the maturity date was extended to September 2016. (11) In February 2015, the maturity date was extended to December 2016. (12) Carrying value is net of $25.0 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (13) Carrying value is net of $5.1 million that was participated out, which is included in other assets and other liabilities on the consolidated balance sheets as a result of the transfer not meeting the conditions for sale accounting. (14) These loans were repaid in April 2015. (15) This loan was repaid in August 2015.
Summary of preferred equity investments	As of September 30, 2015 and December 31, 2014 , we held the following preferred equity investments with an aggregate weighted average current yield of 7.77% at September 30, 2015 (in thousands): Type September 30, 2015 Future Funding Obligations September 30, 2015 Senior Financing September 30, 2015 Carrying Value (1) December 31, 2014 (1) Initial Mandatory Redemption Preferred equity (2) $ — $ 70,000 $ 9,964 $ 9,954 March 2018 Preferred equity 5,580 60,387 32,185 — November 2018 Preferred equity (3) — — — 123,041 $ 5,580 $ 130,387 $ 42,149 $ 132,995 ____________________________________________________________________ (1) Carrying value is net of deferred origination fees. (2) In March 2015, the redemption date was extended to March 2018. (3) This investment was redeemed in July 2015.

Investments in Unconsolidated38

Investments in Unconsolidated Joint Ventures (Tables)	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Schedule of general information on joint ventures	As of September 30, 2015 and December 31, 2014 , the carrying value for acquisition, development and construction arrangements were as follows (in thousands): Loan Type September 30, 2015 December 31, 2014 Initial Maturity Date Mezzanine loan and preferred equity $ 99,856 $ 99,629 March 2016 Mezzanine loan (1) 45,907 46,246 February 2022 $ 145,763 $ 145,875 ____________________________________________________________________ (1) We have an option to convert our loan to equity interest subject to certain conditions. In addition, we have determined that our option to convert the loan to equity is not a derivative financial instrument pursuant to Generally Accepted Accounting Principles, or GAAP. As such, the embedded feature is not required to be bifurcated and the fair value accounting for the embedded feature at each reporting date is not applicable. The table below provides general information on each of our joint ventures as of September 30, 2015 : Property Partner Ownership Interest Economic Interest Approximate Square Feet Acquisition Date Acquisition Price (1) (in thousands) 100 Park Avenue Prudential Real Estate Investors 49.90% 49.90% 834,000 January 2000 $ 95,800 717 Fifth Avenue Jeff Sutton/Private Investor 10.92% 10.92% 119,500 September 2006 251,900 800 Third Avenue (2) Private Investors 60.52% 60.52% 526,000 December 2006 285,000 1745 Broadway Ivanhoe Cambridge, Inc. 56.88% 56.88% 674,000 April 2007 520,000 Jericho Plaza Onyx Equities/Credit Suisse 20.26% 20.26% 640,000 April 2007 210,000 600 Lexington Avenue Canadian Pension Plan Investment Board 55.00% 55.00% 303,515 May 2010 193,000 11 West 34th Street Private Investor/ Jeff Sutton 30.00% 30.00% 17,150 December 2010 10,800 7 Renaissance Louis Cappelli 50.00% 50.00% 65,641 December 2010 4,000 3 Columbus Circle (3) The Moinian Group 48.90% 48.90% 741,500 January 2011 500,000 280 Park Avenue Vornado Realty Trust 50.00% 50.00% 1,219,158 March 2011 400,000 1552-1560 Broadway (4) Jeff Sutton 50.00% 50.00% 35,897 August 2011 136,550 724 Fifth Avenue Jeff Sutton 50.00% 50.00% 65,040 January 2012 223,000 10 East 53rd Street Canadian Pension Plan Investment Board 55.00% 55.00% 354,300 February 2012 252,500 33 Beekman (5) Harel Insurance and Finance/TNG 33 LLC 45.90% 45.90% 163,500 August 2012 31,000 521 Fifth Avenue Plaza Global Real Estate Partners LP 50.50% 50.50% 460,000 November 2012 315,000 21 East 66th Street (6) Private Investors 32.28% 32.28% 16,736 December 2012 75,000 650 Fifth Avenue (7) Jeff Sutton 50.00% 50.00% 32,324 November 2013 — 121 Greene Street Jeff Sutton 50.00% 50.00% 7,131 September 2014 27,400 175-225 Third Street Brooklyn, New York KCLW 3rd Street LLC/LIVWRK LLC 95.00% 95.00% — October 2014 74,600 55 West 46th Street Prudential Real Estate Investors 25.00% 25.00% 347,000 November 2014 295,000 Stonehenge Portfolio (8) Various Various Various 2,046,733 February 2015 36,668 131-137 Spring Street (9) Invesco Real Estate 20.00% 20.00% 68,342 August 2015 277,750 ____________________________________________________________________ (1) Acquisition price represents the actual or implied gross purchase price for the joint venture, which is not adjusted for subsequent acquisitions of additional interest. (2) In March 2015, we acquired an additional 17.56% interest in this joint venture for $67.5 million . (3) As a result of the sale of a condominium interest in September 2012, Young & Rubicam, Inc., or Y&R, owns floors three through eight at the property. Because the joint venture has an option to repurchase these floors, the gain associated with this sale was deferred. (4) The purchase price represents only the purchase of the 1552 Broadway interest which comprised approximately 13,045 square feet. The joint venture also owns a long-term leasehold interest in the retail space and certain other spaces at 1560 Broadway, which is adjacent to 1552 Broadway. (5) The redevelopment project was substantially complete during the second quarter of 2015 and was conveyed to Pace University during the third quarter of 2015. In October 2015, we entered into an agreement to sell the property for $196.0 million . The transaction is expected to be completed in the first half of 2016, subject to customary closing conditions. (6) We hold a 32.28% interest in three retail and two residential units at the property and a 16.14% interest in three residential units at the property. (7) The joint venture owns a long-term leasehold interest in the retail space at 650 Fifth Avenue. In connection with the ground lease obligation, SLG provided a performance guaranty and our joint venture partner executed a contribution agreement to reflect its pro rata obligation. In the event the property is converted into a condominium unit and the landlord elects the purchase option, the joint venture shall be obligated to acquire the unit at the then fair value. (8) In February 2015, we acquired an interest in a portfolio of Manhattan residential and retail properties for $40.2 million , of which $3.5 million represented an increase in ownership interest in six of our existing consolidated joint venture properties. The $40.2 million of consideration included the issuance of $40.0 million aggregate liquidation preference of 3.75% Series M Preferred Units of limited partnership interest of the Operating Partnership. In July 2015, we acquired less than 1.0% of additional interest in the Stonehenge Portfolio for a net purchase price of $1.1 million . (9) In August 2015, we sold an 80% interest in 131-137 Spring Street. These properties, which were previously wholly-owned, were accounted for in the consolidated financial statements. See Note 4, "Properties Held for Sale and Property Dispositions." The following table summarizes the investments in unconsolidated joint ventures sold during the nine months ended September 30, 2015: Property Ownership Percentage Disposition Date Type of Sale Gross Asset Valuation (in millions) (1) Gain (Loss) on Sale (in millions) (2) The Meadows 50.00% August 2015 Property $ 121.1 $ (1.6 ) 315 West 36th Street 35.50% September 2015 Ownership Interest 115.0 16.3 ___________________________________________________________________ (1) Represents implied gross valuation of the property. (2) Represents our share of the gain or loss. The gain on sale for 315 West 36th Street is net of employee compensation awards accrued in connection with the realization of this investment gain as a bonus to certain employees that were instrumental in realizing the gain on sale.
Schedule of first mortgage notes payable collateralized by the respective joint venture properties and assignment of leases	The first mortgage notes and other loans payable collateralized by the respective joint venture properties and assignment of leases at September 30, 2015 and December 31, 2014 , respectively, are as follows (amounts in thousands): Property Maturity Date Interest Rate (1) September 30, 2015 December 31, 2014 Fixed Rate Debt: 7 Renaissance December 2015 10.00 % $ 2,927 $ 2,147 11 West 34th Street January 2016 4.82 % 16,671 16,905 280 Park Avenue June 2016 6.57 % 694,846 700,171 1745 Broadway January 2017 5.68 % 340,000 340,000 Jericho Plaza (2) May 2017 5.65 % 163,750 163,750 800 Third Avenue August 2017 6.00 % 20,910 20,910 521 Fifth Avenue November 2019 3.73 % 170,000 170,000 Property Maturity Date Interest Rate (1) September 30, 2015 December 31, 2014 717 Fifth Avenue (3) July 2022 4.45 % 300,000 300,000 21 East 66th Street April 2023 3.60 % 12,000 12,000 717 Fifth Avenue (3) July 2024 9.00 % 322,769 314,381 3 Columbus Circle (4) March 2025 3.61 % 350,000 — Stonehenge Portfolio (5) Various 4.18 % 433,031 — 315 West 36th Street (6) — 25,000 Total fixed rate debt $ 2,826,904 $ 2,065,264 Floating Rate Debt: 1552 Broadway (7) April 2016 4.32 % 188,409 184,210 Other loan payable June 2016 1.09 % 30,000 30,000 650 Fifth Avenue (8) October 2016 3.70 % 65,000 65,000 175-225 Third Street December 2016 4.25 % 40,000 40,000 10 East 53rd Street February 2017 2.70 % 125,000 125,000 724 Fifth Avenue April 2017 2.62 % 275,000 275,000 33 Beekman (9) August 2017 2.94 % 71,378 52,283 600 Lexington Avenue October 2017 2.29 % 113,786 116,740 55 West 46th Street (10) October 2017 2.50 % 150,000 150,000 Stonehenge Portfolio December 2017 3.25 % 10,500 — 121 Greene Street November 2019 1.70 % 15,000 15,000 131-137 Spring Street August 2020 1.75 % 141,000 — 100 Park Avenue February 2021 1.95 % 360,000 360,000 21 East 66th Street June 2033 3.00 % 1,825 1,883 3 Columbus Circle (4) — 230,974 The Meadows (11) — 67,350 Total floating rate debt $ 1,586,898 $ 1,713,440 Total joint venture mortgages and other loans payable $ 4,413,802 $ 3,778,704 ____________________________________________________________________ (1) Effective weighted average interest rate for the three months ended September 30, 2015 , taking into account interest rate hedges in effect during the period. (2) This loan is in default as of June 30, 2015 due to the non-payment of debt service. (3) These loans are comprised of a $300.0 million fixed rate mortgage loan and $290.0 million mezzanine loan. The mezzanine loan is subject to accretion based on the difference between contractual interest rate and contractual pay rate. (4) In March 2015, the joint venture refinanced the previous mortgage and incurred a net loss on early extinguishment of debt of $0.8 million . (5) Amount is comprised of $13.4 million , $55.8 million , $35.0 million , $7.4 million , $142.1 million , and $179.4 million in fixed-rate mortgages that mature in July 2016, June 2017, November 2017, February 2018, August 2019, and June 2024, respectively. (6) In July 2015, the joint venture refinanced the previous mortgage. In September 2015, the interest in the property was sold for a gross asset valuation of $115.0 million . (7) These loans are comprised of a $150.0 million mortgage loan and a $41.5 million mezzanine loan. As of September 30, 2015 , $1.7 million of the mortgage loan and $1.4 million of the mezzanine loan was unfunded. (8) This loan has a committed amount of $97.0 million , of which $32.0 million was unfunded as of September 30, 2015 . (9) This loan has a committed amount of $75.0 million , of which $18.4 million is recourse to us. Our partner has indemnified us for its pro rata share of the recourse guarantee. A portion of the guarantee terminates upon the joint venture reaching certain milestones. We believe it is unlikely that we will be required to perform under this guarantee. (10) This loan has a committed amount of $190.0 million , of which $40.0 million was unfunded as of September 30, 2015 . (11) In August 2015, these properties were sold and the debt was repaid.
Schedule of combined balance sheets for the unconsolidated joint ventures	The combined balance sheets for the unconsolidated joint ventures, at September 30, 2015 and December 31, 2014, are as follows (in thousands): September 30, 2015 December 31, 2014 Assets Commercial real estate property, net $ 6,282,267 $ 5,275,632 Other assets 906,955 810,567 Total assets $ 7,189,222 $ 6,086,199 Liabilities and members' equity Mortgages and other loans payable $ 4,413,802 $ 3,778,704 Other liabilities 501,637 485,572 Members' equity 2,273,783 1,821,923 Total liabilities and members' equity $ 7,189,222 $ 6,086,199 Company's investments in unconsolidated joint ventures $ 1,239,008 $ 1,172,020
Schedule of combined statements of income for the unconsolidated joint ventures	The combined statements of income for the unconsolidated joint ventures, from acquisition date through the three and nine months ended September 30, 2015 and 2014 are as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Total revenues $ 150,638 $ 114,831 $ 423,089 $ 406,464 Operating expenses 27,647 18,530 79,478 63,575 Ground rent 4,677 2,638 9,841 7,295 Real estate taxes 23,494 15,867 65,205 48,209 Interest expense, net of interest income 51,430 40,885 147,152 137,949 Amortization of deferred financing costs 3,473 2,837 9,628 9,496 Transaction related costs 604 501 615 565 Depreciation and amortization 38,144 28,324 109,022 107,786 Total expenses 149,469 109,582 420,941 374,875 Loss on early extinguishment of debt (248 ) — (1,081 ) (6,743 ) Net income before gain on sale $ 921 $ 5,249 $ 1,067 $ 24,846 Company's equity in net income from unconsolidated joint ventures $ 3,627 $ 6,034 $ 10,651 $ 20,781

Deferred Costs (Tables)

Deferred Costs (Tables)	9 Months Ended
	Sep. 30, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of components of deferred costs	Deferred costs at September 30, 2015 and December 31, 2014 consisted of the following (in thousands): September 30, 2015 December 31, 2014 Deferred leasing $ 405,278 $ 385,555 Deferred financing 211,552 193,776 616,830 579,331 Less accumulated amortization (273,894 ) (251,369 ) Deferred costs, net $ 342,936 $ 327,962

Mortgages and Other Loans Pay40

Mortgages and Other Loans Payable (Tables)	9 Months Ended
	Sep. 30, 2015
Mortgages and Other Loans Payable
Schedule of first mortgages and other loans payable collateralized by the respective properties and assignment of leases	The first mortgages and other loans payable collateralized by the respective properties and assignment of leases at September 30, 2015 and December 31, 2014 , respectively, were as follows (amounts in thousands): Property Maturity Date Interest Rate (1) September 30, 2015 December 31, 2014 Fixed Rate Debt: FHLB Facility October 2015 (2) 0.46 % $ 1,000 $ — 500 West Putnam Avenue January 2016 5.52 % 22,527 22,968 Landmark Square December 2016 4.00 % 79,995 81,269 485 Lexington Avenue February 2017 5.61 % 450,000 450,000 762 Madison Avenue (3) February 2017 3.86 % 7,916 8,045 885 Third Avenue July 2017 6.26 % 267,650 267,650 1745 Broadway June 2018 4.81 % 16,000 16,000 388-390 Greenwich Street (4) June 2018 3.25 % 1,004,000 1,004,000 One Madison Avenue May 2020 5.91 % 548,699 565,742 100 Church Street July 2022 4.68 % 226,000 228,612 919 Third Avenue (5) June 2023 5.12 % 500,000 500,000 400 East 57th Street February 2024 4.13 % 67,962 68,896 400 East 58th Street February 2024 4.13 % 29,126 29,527 420 Lexington Avenue October 2024 3.99 % 300,000 300,000 1515 Broadway March 2025 3.93 % 900,000 900,000 11 Madison Avenue September 2025 3.84 % 1,400,000 — Series J Preferred Units (6) April 2051 3.75 % 4,000 4,000 711 Third Avenue (7) — 120,000 120 West 45th Street (8) — 170,000 Total fixed rate debt $ 5,824,875 $ 4,736,709 Floating Rate Debt: Master Repurchase Agreement June 2016 3.35 % 285,508 100,000 FHLB Facility June 2016 0.53 % 5,000 — 388-390 Greenwich Street (4) June 2018 1.94 % 446,000 446,000 248-252 Bedford Avenue June 2019 1.70 % 29,000 29,000 220 East 42nd Street October 2020 1.80 % 275,000 275,000 180 Maiden Lane (9) — 253,942 Total floating rate debt $ 1,040,508 $ 1,103,942 Total fixed rate and floating rate debt $ 6,865,383 $ 5,840,651 Mortgages reclassed to liabilities related to assets held for sale — (253,942 ) Total mortgages and other loans payable $ 6,865,383 $ 5,586,709 ____________________________________________________________________ (1) Effective weighted average interest rate for the three months ended September 30, 2015 , taking into account interest rate hedges in effect during the period. (2) In October 2015, the maturity date was extended to April 2016. (3) In February 2015, we entered into a new swap agreement with a fixed interest rate of 3.86% per annum, which replaced the previous swap agreement with a fixed interest rate of 3.75% per annum. (4) In connection with the acquisition of our joint venture partner's interest, we assumed the existing derivative instruments, which swapped $504.0 million of the mortgage to a fixed rate mortgage which bears interest at 3.80% per annum. In October 2014, we entered into multiple swap agreements to hedge our interest rate exposure on the additional $500.0 million portion of this mortgage, which was swapped to a fixed rate of 2.69% per annum. Including the as-of right extension option, this loan matures in June 2021. (5) We own a 51.0% controlling interest in the joint venture that is the borrower on this loan. (6) In connection with the acquisition of a commercial real estate property, the Operating Partnership issued $4.0 million , or 4,000 , 3.75% Series J Preferred Units of limited partnership interest, or the Series J Preferred Units, with a mandatory liquidation preference of $1,000.00 per unit. The Series J Preferred Units are accounted for as debt because they can be redeemed in cash by the Operating Partnership on the earlier of (i) the date of the sale of the property or (ii) April 30, 2051 or at the option of the unitholders as further prescribed in the related agreement. (7) In March 2015, we repaid the mortgage. (8) This property was sold in September 2015 and all obligations related to the property accruing on and after the closing date were assumed by the purchaser. (9) This property was held for sale at December 31, 2014 and the related mortgage is included in liabilities related to assets held for sale. In January 2015, the property was sold and the debt was repaid.

Corporate Indebtedness (Tables)

Corporate Indebtedness (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Schedule of senior unsecured notes and other related disclosures by scheduled maturity date	The following table sets forth our senior unsecured notes and other related disclosures as of September 30, 2015 and December 31, 2014 , respectively, by scheduled maturity date (dollars in thousands): Issuance September 30, 2015 Unpaid Principal Balance September 30, 2015 Accreted Balance December 31, 2014 Accreted Balance Coupon Rate (1) Effective Rate Term (in Years) Maturity Date March 31, 2006 (2) $ 255,308 $ 255,284 $ 255,250 6.00 % 6.00 % 10 March 31, 2016 October 12, 2010 (3) 345,000 318,035 309,069 3.00 % 3.00 % 7 October 15, 2017 August 5, 2011 (4) 250,000 249,793 249,744 5.00 % 5.00 % 7 August 15, 2018 March 16, 2010 (4) 250,000 250,000 250,000 7.75 % 7.75 % 10 March 15, 2020 November 15, 2012 (4) 200,000 200,000 200,000 4.50 % 4.50 % 10 December 1, 2022 March 26, 2007 (5) 10,008 10,008 10,008 3.00 % 3.00 % 20 March 30, 2027 June 27, 2005 (2)(6) — — 7 $ 1,310,316 $ 1,283,120 $ 1,274,078 ____________________________________________________________________ (1) Interest on the senior unsecured notes is payable semi-annually with principal and unpaid interest due on the scheduled maturity dates. (2) Issued by ROP. (3) Issued by the Operating Partnership. Interest on these exchangeable notes is payable semi-annually on April 15 and October 15. The notes had an initial exchange rate representing an exchange price that was set at a 30.0% premium to the last reported sale price of SL Green's common stock on October 6, 2010, or $85.81 . The initial exchange rate is subject to adjustment under certain circumstances. The current exchange rate is 12.2732 shares of SL Green's common stock per $1,000 principal amount of these notes. The notes are senior unsecured obligations of the Operating Partnership and are exchangeable upon the occurrence of specified events and during the period beginning on the twenty-second scheduled trading day prior to the maturity date and ending on the second business day prior to the maturity date, into cash or a combination of cash and shares of SL Green's common stock, if any, at our option. As a result of meeting specified events (as defined in the Indenture Agreement), these notes became exchangeable commencing January 1, 2015 and will remain exchangeable through September 30, 2015. The notes are guaranteed by ROP. On the issuance date, $78.3 million of the debt balance was recorded in equity. As of September 30, 2015 , $27.0 million remained to be amortized into the debt balance. (4) Issued by the Company, the Operating Partnership and ROP, as co-obligors. (5) Issued by the Operating Partnership. Interest on these remaining exchangeable notes is payable semi-annually on March 30 and September 30. The notes have an initial exchange rate representing an exchange price that was set at a 25.0% premium to the last reported sale price of the Company's common stock on March 20, 2007, or $173.30 . The initial exchange rate is subject to adjustment under certain circumstances. The current exchange rate is 5.7952 shares of SL Green's common stock per $1,000 principal amount of these notes. The notes are senior unsecured obligations of the Operating Partnership and are exchangeable upon the occurrence of specified events and during the period beginning on the twenty-second scheduled trading day prior to the maturity date and ending on the second business day prior to the maturity date, into cash or a combination of cash and shares of SL Green's common stock, if any, at our option. The notes are currently redeemable at the Operating Partnership’s option. The Operating Partnership may be required to repurchase the notes on March 30, 2017 and 2022, and upon the occurrence of certain designated events. (6) In April 2015, we redeemed the remaining outstanding debentures.
Schedule of combined aggregate principal maturities	Combined aggregate principal maturities of mortgages and other loans payable, 2012 credit facility, trust preferred securities, senior unsecured notes and our share of joint venture debt as of September 30, 2015 , including as-of-right extension options and put options, were as follows (in thousands): Scheduled Amortization Principal Repayments Revolving Credit Facility Unsecured Term Loan Trust Preferred Securities Senior Unsecured Notes Total Joint Venture Debt Remaining 2015 $ 7,716 $ 1,000 $ — $ — $ — $ — $ 8,716 $ 2,961 2016 47,360 390,819 — — — 255,308 693,487 534,036 2017 61,063 725,329 — — — 355,008 1,141,400 580,044 2018 64,462 16,000 — — — 250,000 330,462 2,196 2019 70,409 28,317 — 933,000 — — 1,031,726 104,687 Thereafter 200,403 5,252,505 949,000 — 100,000 450,000 6,951,908 474,942 $ 451,413 $ 6,413,970 $ 949,000 $ 933,000 $ 100,000 $ 1,310,316 $ 10,157,699 $ 1,698,866
Schedule of consolidated interest expense, excluding capitalized interest	Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Interest expense $ 84,917 $ 83,158 $ 237,847 $ 238,285 Interest income (776 ) (782 ) (2,153 ) (1,861 ) Interest expense, net $ 84,141 $ 82,376 $ 235,694 $ 236,424 Interest capitalized $ 7,327 $ 7,972 $ 23,496 $ 18,689

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Schedule of amounts due from/to related parties	Amounts due from related parties at September 30, 2015 and December 31, 2014 consisted of the following (in thousands): September 30, 2015 December 31, 2014 Due from joint ventures $ 1,343 $ 1,254 Other 9,746 10,481 Related party receivables $ 11,089 $ 11,735

Noncontrolling Interests on t43

Noncontrolling Interests on the Company's Consolidated Financial Statements (Tables)	9 Months Ended
	Sep. 30, 2015
Noncontrolling Interest [Abstract]
Schedule of Noncontrolling Interest	Below is the rollforward analysis of the activity relating to the noncontrolling interests in the Operating Partnership as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Balance at beginning of period $ 469,524 $ 265,476 Distributions (7,017 ) (7,849 ) Issuance of common units 27,898 56,469 Redemption of common units (41,605 ) (31,653 ) Net income 6,634 18,467 Accumulated other comprehensive income allocation (349 ) 175 Fair value adjustment (31,664 ) 168,439 Balance at end of period $ 423,421 $ 469,524
Schedule of Preferred Unit Activity	Below is the rollforward analysis of the activity relating to the preferred units in the Operating Partnership as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Balance at beginning of period $ 71,115 $ 49,550 Issuance of preferred units 211,601 23,565 Redemption of preferred units (200 ) (2,000 ) Balance at end of period $ 282,516 $ 71,115

Stockholders' Equity of the C44

Stockholders' Equity of the Company (Tables)	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Schedule of Earnings Per Share	SL Green's earnings per share for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic Earnings: Income attributable to SL Green common stockholders $ 163,658 $ 64,688 $ 167,829 $ 446,319 Effect of Dilutive Securities: Redemption of units to common shares 6,468 2,636 6,634 16,010 Diluted Earnings: Income attributable to SL Green common stockholders $ 170,126 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic Shares: Weighted average common stock outstanding 99,621 95,734 99,205 95,437 Effect of Dilutive Securities: Redemption of units to common shares 3,901 3,585 3,924 3,423 Stock-based compensation plans 407 387 480 462 Diluted weighted average common stock outstanding 103,929 99,706 103,609 99,322

Partners' Capital of the Oper45

Partners' Capital of the Operating Partnership (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Schedule of calculation of numerator and denominator in earnings per unit	The Operating Partnership's earnings per unit for the three and nine months ended September 30, 2015 and 2014 are computed as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2015 2014 2015 2014 Basic and Diluted Earnings: Income attributable to SLGOP common unitholders $ 170,125 $ 67,324 $ 174,463 $ 462,329 Three Months Ended September 30, Nine Months Ended September 30, Denominator 2015 2014 2015 2014 Basic units: Weighted average common units outstanding 103,522 99,319 103,129 98,860 Effect of Dilutive Securities: Stock-based compensation plans 407 387 480 462 Diluted weighted average common units outstanding 103,929 99,706 103,609 99,322

Share-based Compensation (Table

Share-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of weighted average assumptions used to estimate the grant date fair value of options granted	The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes option pricing model based on historical information with the following weighted average assumptions for grants during the nine months ended September 30, 2015 and year ended December 31, 2014 . September 30, 2015 December 31, 2014 Dividend yield 1.74 % 1.60 % Expected life of option 3.5 years 3.6 years Risk-free interest rate 1.17 % 1.29 % Expected stock price volatility 34.59 % 33.97 %
Summary of the status of stock options and changes during the period	A summary of the status of the Company's stock options as of September 30, 2015 and December 31, 2014 and changes during the nine months ended September 30, 2015 and the year ended December 31, 2014 are as follows: September 30, 2015 December 31, 2014 Options Outstanding Weighted Average Exercise Price Options Outstanding Weighted Average Exercise Price Balance at beginning of year 1,462,726 $ 87.98 1,765,034 $ 83.24 Granted 40,500 117.50 102,050 119.12 Exercised (170,035 ) 75.33 (348,156 ) 72.76 Lapsed or cancelled (30,417 ) 98.41 (56,202 ) 90.03 Balance at end of period 1,302,774 $ 90.30 1,462,726 $ 87.98 Options exercisable at end of period 594,624 $ 88.44 428,951 $ 90.32 Weighted average fair value of options granted during the period $ 1,112,152 $ 2,841,678
Summary of restricted stock and charges during the period	A summary of the Company's restricted stock as of September 30, 2015 and December 31, 2014 and charges during the nine months ended September 30, 2015 and the year ended December 31, 2014 are as follows: September 30, 2015 December 31, 2014 Balance at beginning of period 3,000,979 2,994,197 Granted 6,053 9,550 Cancelled (3,717 ) (2,768 ) Balance at end of period 3,003,315 3,000,979 Vested during the period 87,081 75,043 Compensation expense recorded $ 5,663,196 $ 9,658,019 Weighted average fair value of restricted stock granted during the period $ 735,011 $ 1,141,675

Accumulated Other Comprehensi47

Accumulated Other Comprehensive Loss of the Company (Tables)	9 Months Ended
	Sep. 30, 2015
SL Green Realty Corp
Accumulated Other Comprehensive Income (Loss) [Line Items]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following tables set forth the changes in accumulated other comprehensive income (loss) by component as of September 30, 2015 (in thousands): Net unrealized (loss) gain on derivative instruments ( 1 ) SL Green’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Unrealized gain (loss) on marketable securities Total Balance at December 31, 2014 $ (9,498 ) $ (95 ) $ 2,613 $ (6,980 ) Other comprehensive loss before reclassifications (14,918 ) (2,393 ) (351 ) (17,662 ) Amounts reclassified from accumulated other comprehensive income 7,908 913 — 8,821 Balance at September 30, 2015 $ (16,508 ) $ (1,575 ) $ 2,262 $ (15,821 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of September 30, 2015 and December 31, 2014 , the deferred net losses from these terminated hedges, which is included in accumulated other comprehensive loss relating to net unrealized loss on derivative instrument, was $10.3 million and $11.8 million , respectively. (2) Amount reclassified from accumulated other comprehensive income (loss) is included in equity in net income from unconsolidated joint ventures in the respective consolidated statements of operations.

Accumulated Other Comprehensi48

Accumulated Other Comprehensive Loss of the Operating Partnership (Tables)	9 Months Ended
	Sep. 30, 2015
SL Green Operating Partnership
Accumulated Other Comprehensive Income (Loss) [Line Items]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following tables set forth the changes in accumulated other comprehensive income (loss) by component as of September 30, 2015 (in thousands): Net unrealized (loss) gain on derivative instruments ( 1 ) SLGOP’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Unrealized gain (loss) on marketable securities Total Balance at December 31, 2014 $ (9,845 ) $ (100 ) $ 2,689 $ (7,256 ) Other comprehensive loss before reclassifications (15,537 ) (2,486 ) (337 ) (18,360 ) Amounts reclassified from accumulated other comprehensive income 8,221 949 — 9,170 Balance at September 30, 2015 $ (17,161 ) $ (1,637 ) $ 2,352 $ (16,446 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of September 30, 2015 and December 31, 2014, the deferred net losses from these terminated hedges, which is included in accumulated other comprehensive loss relating to net unrealized loss on derivative instrument, was $10.7 million and $12.2 million , respectively. (2) Amount reclassified from accumulated other comprehensive income (loss) is included in equity in net income from unconsolidated joint ventures in the respective consolidated statements of operations.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The following tables set forth the assets and liabilities that we measure at fair value on a recurring and non-recurring basis by their levels in the fair value hierarchy at September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 Total Level 1 Level 2 Level 3 Assets: Marketable securities $ 46,432 $ 4,115 $ 42,317 $ — Interest rate cap and swap agreements (included in other assets) $ 7 $ — $ 7 $ — Liabilities: Interest rate cap swap agreements (included in accrued interest payable and other liabilities) $ 18,019 $ — $ 18,019 $ — December 31, 2014 Total Level 1 Level 2 Level 3 Assets: Marketable securities $ 39,429 $ 4,332 $ 35,097 $ — Interest rate swap agreements (included in other assets) $ 2,174 $ — $ 2,174 $ — Liabilities: Interest rate swap agreements (included in accrued interest payable and other liabilities) $ 14,728 $ — $ 14,728 $ —
Fair Value, by Balance Sheet Grouping	The following table provides the carrying value and fair value of these financial instruments as of September 30, 2015 and December 31, 2014 (in thousands): September 30, 2015 December 31, 2014 Carrying Value Fair Value Carrying Value Fair Value Debt and preferred equity investments $ 1,501,619 (1) $ 1,408,804 (1) Fixed rate debt $ 7,137,995 $ 7,610,830 $ 6,140,786 $ 6,565,236 Variable rate debt 2,992,508 3,015,758 2,291,943 2,315,952 $ 10,130,503 $ 10,626,588 $ 8,432,729 $ 8,881,188 ____________________________________________________________________ (1) At September 30, 2015 , debt and preferred equity investments had an estimated fair value ranging between $1.7 billion and $1.9 billion . At December 31, 2014, debt and preferred equity investments had an estimated fair value ranging between $1.5 billion and $1.8 billion .

Financial Instruments_ Deriva50

Financial Instruments: Derivatives and Hedging (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of notional and fair value of derivative financial instruments and foreign currency hedges	The following table summarizes the notional value at inception and fair value of our consolidated derivative financial instruments at September 30, 2015 based on Level 2 information. The notional value is an indication of the extent of our involvement in these instruments at that time, but does not represent exposure to credit, interest rate or market risks (amounts in thousands). Notional Value Strike Rate Effective Date Expiration Date Balance Sheet Location Fair Value Interest Rate Cap - Sold $ 504,000 4.750 % May 2014 May 2016 Other Liabilities $ — Interest Rate Cap 504,000 4.750 % May 2014 May 2016 Other Assets — Interest Rate Cap 500,000 4.750 % October 2014 May 2016 Other Liabilities — Interest Rate Cap - Sold 500,000 4.750 % November 2014 May 2016 Other Assets — Interest Rate Cap 446,000 4.750 % October 2014 May 2016 Other Liabilities — Interest Rate Cap 263,426 6.000 % November 2013 November 2015 Other Liabilities — Interest Rate Swap 200,000 0.938 % October 2014 December 2017 Other Liabilities (1,087 ) Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Liabilities (821 ) Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Liabilities (821 ) Interest Rate Swap 144,000 2.236 % December 2012 December 2017 Other Liabilities (4,812 ) Interest Rate Swap 86,400 1.948 % December 2012 December 2017 Other Liabilities (2,345 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (2,522 ) Interest Rate Swap 72,000 1.345 % December 2012 December 2017 Other Liabilities (1,012 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (2,522 ) Interest Rate Swap 57,600 1.990 % December 2012 December 2017 Other Liabilities (1,616 ) Interest Rate Swap 30,000 2.295 % July 2010 June 2016 Other Liabilities (415 ) Interest Rate Swap 14,409 0.500 % January 2015 January 2017 Other Liabilities (7 ) Interest Rate Swap 8,018 0.852 % February 2015 February 2017 Other Liabilities (39 ) Interest Rate Cap 137,500 4.000 % September 2015 September 2017 Other Assets 7 $ (18,012 )
Schedule of effect of derivative financial instruments on consolidated statements of income	The following table presents the effect of our derivative financial instruments and our share of our joint ventures' derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the three months ended September 30, 2015 and 2014, respectively (in thousands): Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion) Location of (Loss) Reclassified from Accumulated Other Comprehensive Loss into Income Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Location of (Loss) or Gain Recognized in Income on Derivative Amount of (Loss) or Gain Recognized into Income (Ineffective Portion) Three Months Ended September 30, Three Months Ended September 30, Three Months Ended September 30, Derivative 2015 2014 2015 2014 2015 2014 Interest Rate Swaps/Caps $ (6,921 ) $ 1,761 Interest expense $ 2,737 $ 1,826 Interest expense $ (31 ) $ 1 Share of unconsolidated joint ventures' derivative instruments (1,526 ) 291 Equity in net income from unconsolidated joint ventures 287 41 Equity in net income from unconsolidated joint ventures (21 ) — $ (8,447 ) $ 2,052 $ 3,024 $ 1,867 $ (52 ) $ 1 The following table presents the effect of our derivative financial instruments and our share of our joint ventures' derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the nine months ended September 30, 2015 and 2014, respectively (in thousands): Amount of (Loss) or Gain Location of(Loss) Reclassified from Accumulated Other Comprehensive Loss into Income Amount of Loss Location of (Loss) or Gain Recognized in Income on Derivative Amount of (Loss) or Gain Nine Months Ended September 30, Nine Months Ended September 30, Nine Months Ended September 30, Derivative 2015 2014 2015 2014 2015 2014 Interest Rate Swaps/Caps $ (15,537 ) $ 1,245 Interest expense $ 8,221 $ 3,790 Interest expense $ (455 ) $ 3 Share of unconsolidated joint ventures' derivative instruments (2,486 ) 4,475 Equity in net income from unconsolidated joint ventures 949 1,870 Equity in net income from unconsolidated joint ventures (21 ) — $ (18,023 ) $ 5,720 $ 9,170 $ 5,660 $ (476 ) $ 3

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The following is a schedule of future minimum lease payments under capital leases and non-cancellable operating leases with initial terms in excess of one year as of September 30, 2015 (in thousands): Capital lease Non-cancellable operating leases Remaining 2015 $ 560 $ 7,675 2016 2,266 30,816 2017 2,387 31,049 2018 2,387 31,049 2019 2,411 31,066 Thereafter 828,103 795,787 Total minimum lease payments 838,114 $ 927,442 Less amount representing interest (796,943 ) Capital lease obligations $ 41,171
Schedule of Future Minimum Lease Payments for Capital Leases	The following is a schedule of future minimum lease payments under capital leases and non-cancellable operating leases with initial terms in excess of one year as of September 30, 2015 (in thousands): Capital lease Non-cancellable operating leases Remaining 2015 $ 560 $ 7,675 2016 2,266 30,816 2017 2,387 31,049 2018 2,387 31,049 2019 2,411 31,066 Thereafter 828,103 795,787 Total minimum lease payments 838,114 $ 927,442 Less amount representing interest (796,943 ) Capital lease obligations $ 41,171

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of selected results of operations and selected asset information	Selected results of operations for the three and nine months ended September 30, 2015 and 2014, and selected asset information as of September 30, 2015 and December 31, 2014, regarding our operating segments are as follows (in thousands): Real Estate Segment Debt and Preferred Equity Segment Total Company Total revenues Three months ended: September 30, 2015 $ 382,738 $ 49,328 $ 432,066 September 30, 2014 346,305 43,969 390,274 Nine months ended: September 30, 2015 $ 1,100,851 $ 136,588 $ 1,237,439 September 30, 2014 995,584 137,767 1,133,351 (Loss) income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate and purchase price fair value adjustment Three months ended: September 30, 2015 $ (22,486 ) $ 43,480 $ 20,994 September 30, 2014 (10,542 ) 38,098 27,556 Nine months ended: September 30, 2015 $ (81,405 ) $ 114,677 $ 33,272 September 30, 2014 13,148 117,673 130,821 Total assets As of: September 30, 2015 $ 17,966,608 $ 1,523,961 $ 19,490,569 December 31, 2014 15,671,662 1,424,925 17,096,587
Schedule of reconciliation of income from continuing operations to net income attributable to SL Green common stockholders	The table below reconciles income from continuing operations to net income for the three and nine months ended September 30, 2015 and 2014 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate and purchase price fair value adjustment $ 20,994 $ 27,556 $ 33,272 $ 130,821 Equity in net gain on sale of interest in unconsolidated joint venture/real estate 15,281 16,496 16,050 122,580 Purchase price fair value adjustment — (4,000 ) — 67,446 Gain on sale of real estate 159,704 — 159,704 — Depreciable real estate reserves (19,226 ) — (19,226 ) — Income from continuing operations 176,753 40,052 189,800 320,847 Net income from discontinued operations — 4,035 427 15,449 Gain on sale of discontinued operations — 29,507 12,983 144,242 Net income $ 176,753 $ 73,594 $ 203,210 $ 480,538

Organization and Basis of Pre53

Organization and Basis of Presentation (Details) - SL Green Operating Partnership	Sep. 30, 2015	Dec. 31, 2014
Organization
Percentage of ownership in SL Green Management LLC owned by operating partnership (percent)	100.00%
Noncontrolling interest in the operating partnership (as a percent)	3.74%	3.92%
Service Corporation
Organization
Economic interest in variable interest entity (as a percent)	95.00%

Organization and Basis of Pre54

Organization and Basis of Presentation (Details 2) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)ft²buildingpropertyshares	Dec. 31, 2014USD ($)
Real estate properties
Number of Properties | building	118
Approximate Square Feet (sqft)	35,843,296
Weighted Average Occupancy (as a percent)	90.20%
Carrying Value, Net of Discounts and Deferred Origination Fees | $	$ 1,501,619	$ 1,408,804
Number of shares to be received on redemption of one unit of limited partnership interests (shares) | shares	1
Commercial properties
Real estate properties
Number of Properties | building	95
Approximate Square Feet (sqft)	32,803,865
Weighted Average Occupancy (as a percent)	89.80%
Residential
Real estate properties
Number of Properties | building	23
Approximate Square Feet (sqft)	3,039,431
Weighted Average Occupancy (as a percent)	94.60%
Managed office properties
Real estate properties
Approximate Square Feet (sqft)	336,201
Consolidated properties
Real estate properties
Number of Properties | building	77
Approximate Square Feet (sqft)	27,298,174
Consolidated properties | Commercial properties
Real estate properties
Number of Properties | building	72
Approximate Square Feet (sqft)	26,468,976
Consolidated properties | Residential
Real estate properties
Number of Properties | building	5
Approximate Square Feet (sqft)	829,198
Unconsolidated properties
Real estate properties
Number of Properties | building	41
Approximate Square Feet (sqft)	8,545,122
Unconsolidated properties | Commercial properties
Real estate properties
Number of Properties | building	23
Approximate Square Feet (sqft)	6,334,889
Unconsolidated properties | Residential
Real estate properties
Number of Properties | building	18
Approximate Square Feet (sqft)	2,210,233
Manhattan
Real estate properties
Number of Properties | building	61
Approximate Square Feet (sqft)	27,594,824
Weighted Average Occupancy (as a percent)	91.50%
Manhattan | Office
Real estate properties
Number of Properties | building	32
Approximate Square Feet (sqft)	24,028,587
Weighted Average Occupancy (as a percent)	94.50%
Manhattan | Retail
Real estate properties
Number of Properties | building	18
Approximate Square Feet (sqft)	756,963
Weighted Average Occupancy (as a percent)	91.20%
Manhattan | Development/Redevelopment
Real estate properties
Number of Properties | building	9
Approximate Square Feet (sqft)	2,025,744
Weighted Average Occupancy (as a percent)	53.80%
Number of properties held for sale | property	2
Manhattan | Fee Interest
Real estate properties
Number of Properties | building	2
Approximate Square Feet (sqft)	783,530
Weighted Average Occupancy (as a percent)	100.00%
Manhattan | Residential
Real estate properties
Number of Properties | building	22
Approximate Square Feet (sqft)	2,972,820
Weighted Average Occupancy (as a percent)	94.60%
Manhattan | Consolidated properties
Real estate properties
Number of Properties | building	42
Approximate Square Feet (sqft)	21,965,576
Manhattan | Consolidated properties | Office
Real estate properties
Number of Properties | building	26
Approximate Square Feet (sqft)	20,700,091
Manhattan | Consolidated properties | Retail
Real estate properties
Number of Properties | building	9
Approximate Square Feet (sqft)	408,993
Manhattan | Consolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	5
Approximate Square Feet (sqft)	72,962
Manhattan | Consolidated properties | Fee Interest
Real estate properties
Number of Properties | building	2
Approximate Square Feet (sqft)	783,530
Manhattan | Consolidated properties | Residential
Real estate properties
Number of Properties | building	4
Approximate Square Feet (sqft)	762,587
Manhattan | Consolidated properties | Dual property type, retail portion
Real estate properties
Approximate Square Feet (sqft)	270,132
Manhattan | Consolidated properties | Dual property type, residential portion
Real estate properties
Approximate Square Feet (sqft)	222,855
Manhattan | Unconsolidated properties
Real estate properties
Number of Properties | building	19
Approximate Square Feet (sqft)	5,629,248
Manhattan | Unconsolidated properties | Office
Real estate properties
Number of Properties | building	6
Approximate Square Feet (sqft)	3,328,496
Manhattan | Unconsolidated properties | Retail
Real estate properties
Number of Properties | building	9
Approximate Square Feet (sqft)	347,970
Manhattan | Unconsolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	4
Approximate Square Feet (sqft)	1,952,782
Manhattan | Unconsolidated properties | Fee Interest
Real estate properties
Number of Properties | building	0
Approximate Square Feet (sqft)	0
Manhattan | Unconsolidated properties | Residential
Real estate properties
Number of Properties | building	18
Approximate Square Feet (sqft)	2,210,233
Suburban
Real estate properties
Number of Properties | building	34
Approximate Square Feet (sqft)	5,209,041
Weighted Average Occupancy (as a percent)	80.30%
Suburban | Office
Real estate properties
Number of Properties | building	31
Approximate Square Feet (sqft)	5,156,041
Weighted Average Occupancy (as a percent)	80.10%
Suburban | Retail
Real estate properties
Number of Properties | building	1
Approximate Square Feet (sqft)	52,000
Weighted Average Occupancy (as a percent)	100.00%
Number of properties held for sale | property	2
Suburban | Development/Redevelopment
Real estate properties
Number of Properties | building	2
Approximate Square Feet (sqft)	1,000
Weighted Average Occupancy (as a percent)	100.00%
Suburban | Residential
Real estate properties
Number of Properties | building	1
Approximate Square Feet (sqft)	66,611
Weighted Average Occupancy (as a percent)	95.80%
Suburban | Consolidated properties
Real estate properties
Number of Properties | building	30
Approximate Square Feet (sqft)	4,503,400
Suburban | Consolidated properties | Office
Real estate properties
Number of Properties | building	28
Approximate Square Feet (sqft)	4,450,400
Suburban | Consolidated properties | Retail
Real estate properties
Number of Properties | building	1
Approximate Square Feet (sqft)	52,000
Suburban | Consolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	1
Approximate Square Feet (sqft)	1,000
Suburban | Consolidated properties | Residential
Real estate properties
Number of Properties | building	1
Approximate Square Feet (sqft)	66,611
Suburban | Unconsolidated properties
Real estate properties
Number of Properties | building	4
Approximate Square Feet (sqft)	705,641
Suburban | Unconsolidated properties | Office
Real estate properties
Number of Properties | building	3
Approximate Square Feet (sqft)	705,641
Suburban | Unconsolidated properties | Retail
Real estate properties
Number of Properties | building	0
Approximate Square Feet (sqft)	0
Suburban | Unconsolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	1
Approximate Square Feet (sqft)	0
Suburban | Unconsolidated properties | Residential
Real estate properties
Number of Properties | building	0
Approximate Square Feet (sqft)	0

Significant Accounting Polici55

Significant Accounting Policies (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Principles of Consolidation
Commercial real estate properties	$ 14,261,102	$ 12,163,976
Mortgages and other loans payable	6,865,383	5,586,709
Assets held for sale	117,885	462,430
Liabilities related to assets held for sale	94	266,873
Consolidated VIEs
Principles of Consolidation
Commercial real estate properties	198,600	198,400
Mortgages and other loans payable	$ 105,000	106,500
Commercial properties | Consolidated VIEs
Principles of Consolidation
Assets held for sale		445,000
Liabilities related to assets held for sale		$ 253,900

Significant Accounting Polici56

Significant Accounting Policies (Details 2) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)property	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Investment in Commercial Real Estate Properties
Number of properties expected to be sold | property	2
Increase in rental revenue from amortization of acquired leases	$ 10,200	$ 5,700	$ 32,900	$ 18,200
Reduction in interest expense from amortization of above-market rate mortgages	600	$ 1,300	1,700	$ 4,100
Identified intangible assets (included in other assets):
Gross amount	939,518		939,518		$ 664,297
Accumulated amortization	(392,854)		(392,854)		(383,236)
Net	546,664		546,664		281,061
Identified intangible liabilities (included in deferred revenue):
Gross amount	866,561		866,561		655,755
Accumulated amortization	(476,272)		(476,272)		(483,948)
Net	390,289		390,289		$ 171,807
Net intangible assets reclassed to assets held for sale	200		200
Net intangible liabilities reclassed to liabilities relates to assets held for sale	100		$ 100
Above-market leases | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			1 year
Above-market leases | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			14 years
Below-market leases | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			1 year
Below-market leases | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			14 years
In-place leases | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			1 year
In-place leases | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)			14 years
Building | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)			3 years
Building | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)			40 years
140-150 Grand Street
Investment in Commercial Real Estate Properties
Impairment Charge	$ 19,200

Significant Accounting Polici57

Significant Accounting Policies (Details 3) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Investment in Marketable Securities
Marketable securities	$ 46,432		$ 39,429
Cost basis	39,700		32,400
Proceeds from sale of marketable securities	432	$ 3,669
Equity marketable securities
Investment in Marketable Securities
Marketable securities	4,115		4,332
Mortgage-backed securities
Investment in Marketable Securities
Marketable securities	42,317		35,097
Fair Value
Investment in Marketable Securities
Marketable securities	$ 46,432		$ 39,429

Significant Accounting Polici58

Significant Accounting Policies (Details 4) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accounting Policies [Abstract]
Days past due for income recognition on debt and preferred equity investments to be suspended			90 days
Income taxes
Federal, state and local tax provision	$ 1.1	$ 1.6	$ 2.5	$ 6.6

Significant Accounting Polici59

Significant Accounting Policies (Details 5) - Annualized rent - Customer concentration	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015Tenant
Concentration of Credit Risk
Number of tenants (tenants)		3
Maximum percentage of annualized rent for any one tenant not individually disclosed (percent) (more than)	5.00%	5.00%
1515 Broadway
Concentration of Credit Risk
Percentage of concentration (percent)	9.70%
388-390 Greenwich Street
Concentration of Credit Risk
Percentage of concentration (percent)	8.80%
919 Third Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	7.30%
1185 Avenue of the Americas
Concentration of Credit Risk
Percentage of concentration (percent)	7.00%
11 Madison Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	6.70%
420 Lexington Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	5.70%
1 Madison Ave
Concentration of Credit Risk
Percentage of concentration (percent)	5.40%
Tenant 1
Concentration of Credit Risk
Percentage of concentration (percent)		9.80%
Tenant 2
Concentration of Credit Risk
Percentage of concentration (percent)		9.20%
Tenant 3
Concentration of Credit Risk
Percentage of concentration (percent)		6.30%

Property Acquisitions (Details)

Property Acquisitions (Details) - USD ($) $ in Thousands	May. 15, 2014	May. 14, 2014	Aug. 31, 2015	Jul. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Oct. 31, 2014	Sep. 30, 2014	Jul. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Recognized Identifiable Assets Acquired and Liabilities Assumed
Impact to rental revenue for amortization of aggregate below-market leases										$ 318,465	$ 291,293	$ 926,020	$ 826,877
Impact to depreciation expense										146,185	94,443	454,087	274,337
Total fixed rate debt										5,824,875		5,824,875		$ 4,736,709
108 Broadway and 5 & 7 Dev Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land			$ 22,101
Building and building leasehold			41,045
Above market lease value			0
Acquired in-place leases			0
Other assets, net of other liabilities			0
Assets acquired			63,146
Mark-to-market assumed debt			0
Below market lease value			0
Derivatives			0
Liabilities assumed			0
Purchase price			63,146
Net consideration funded by us at closing, excluding consideration financed by debt			63,146
Equity and/or debt investment held			0
Debt assumed			0
108 Broadway and 5 & 7 Dev Street | Series R Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units										10,000		10,000
108 Broadway and 5 & 7 Dev Street | Series S Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units										$ 26,900		$ 26,900
11 Madison Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land			849,926
Building and building leasehold			1,579,118
Above market lease value			0
Acquired in-place leases			0
Other assets, net of other liabilities			0
Assets acquired			2,429,044
Mark-to-market assumed debt			0
Below market lease value			0
Derivatives			0
Liabilities assumed			0
Purchase price			2,429,044
Net consideration funded by us at closing, excluding consideration financed by debt			2,429,044
Equity and/or debt investment held			0
Debt assumed			$ 0
110 Greene Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land				$ 89,250
Building and building leasehold				165,750
Above market lease value				0
Acquired in-place leases				0
Other assets, net of other liabilities				0
Assets acquired				255,000
Mark-to-market assumed debt				0
Below market lease value				0
Derivatives				0
Liabilities assumed				0
Purchase price				255,000
Net consideration funded by us at closing, excluding consideration financed by debt				255,000
Equity and/or debt investment held				0
Debt assumed				$ 0
Ownership interest in consolidated joint venture (as a percent)										90.00%		90.00%
110 Greene Street | Series P Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units										$ 5,000		$ 5,000
110 Greene Street | Series Q Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units										$ 6,700		6,700
Upper East Side Residential
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land					$ 17,500
Building and building leasehold					32,500
Above market lease value					0
Acquired in-place leases					0
Other assets, net of other liabilities					0
Assets acquired					50,000
Mark-to-market assumed debt					0
Below market lease value					0
Derivatives					0
Liabilities assumed					0
Purchase price					50,000
Net consideration funded by us at closing, excluding consideration financed by debt					50,000
Equity and/or debt investment held					0
Debt assumed					$ 0
Ownership interest in consolidated joint venture (as a percent)					95.10%
Upper East Side Residential | Series N Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units					$ 13,800
1640 Flatbush Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land						$ 6,120
Building and building leasehold						680
Above market lease value						0
Acquired in-place leases						0
Other assets, net of other liabilities						0
Assets acquired						6,800
Mark-to-market assumed debt						0
Below market lease value						0
Derivatives						0
Liabilities assumed						0
Purchase price						6,800
Net consideration funded by us at closing, excluding consideration financed by debt						6,800
Equity and/or debt investment held						0
Debt assumed						$ 0
102 Greene Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land							$ 8,215
Building and building leasehold							26,717
Above market lease value							0
Acquired in-place leases							1,015
Other assets, net of other liabilities							3
Assets acquired							35,950
Mark-to-market assumed debt							0
Below market lease value							3,701
Derivatives							0
Liabilities assumed							3,701
Purchase price							32,249
Net consideration funded by us at closing, excluding consideration financed by debt							32,249
Equity and/or debt investment held							0
Debt assumed							0
102 Greene Street | Scenario, Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land							11,300
Building and building leasehold							21,000
635 Madison Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land								$ 205,632			205,632		205,632
Building and building leasehold								15,805			15,805		15,805
Above market lease value								0			0		0
Acquired in-place leases								17,345			17,345		17,345
Other assets, net of other liabilities								0			0		0
Assets acquired								238,782			238,782		238,782
Mark-to-market assumed debt								0			0		0
Below market lease value								85,036			85,036		85,036
Derivatives								0			0		0
Liabilities assumed								85,036			85,036		85,036
Purchase price								153,746			153,746		153,746
Net consideration funded by us at closing, excluding consideration financed by debt								153,746
Equity and/or debt investment held								0
Debt assumed								0
635 Madison Avenue | Scenario, Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land								$ 153,700			$ 153,700		$ 153,700
719 Seventh Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land									$ 41,850
Building and building leasehold									0
Above market lease value									0
Acquired in-place leases									0
Other assets, net of other liabilities									0
Assets acquired									41,850
Mark-to-market assumed debt									0
Below market lease value									0
Derivatives									0
Liabilities assumed									0
Purchase price									41,850
Net consideration funded by us at closing, excluding consideration financed by debt									41,850
Equity and/or debt investment held									0
Debt assumed									$ 0
Ownership interest in consolidated joint venture (as a percent)									75.00%
719 Seventh Avenue | Series L Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units									$ 14,100
719 Seventh Avenue | Series K Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units									9,500
719 Seventh Avenue | Scenario, Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land									14,400
Building and building leasehold									26,700
115 Spring Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land									11,078
Building and building leasehold									44,799
Above market lease value									0
Acquired in-place leases									2,037
Other assets, net of other liabilities									0
Assets acquired									57,914
Mark-to-market assumed debt									0
Below market lease value									4,789
Derivatives									0
Liabilities assumed									4,789
Purchase price									53,125
Net consideration funded by us at closing, excluding consideration financed by debt									53,125
Equity and/or debt investment held									0
Debt assumed									0
115 Spring Street | Scenario, Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land									15,900
Building and building leasehold									$ 37,200
388-390 Greenwich Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land	$ 516,292
Building and building leasehold	964,434
Above market lease value	0
Acquired in-place leases	302,430
Other assets, net of other liabilities	6,495
Assets acquired	1,789,651
Mark-to-market assumed debt	0
Below market lease value	186,782
Derivatives	18,001
Liabilities assumed	204,783
Purchase price	1,584,868	$ 1,585,000
Net consideration funded by us at closing, excluding consideration financed by debt	208,614	208,614
Equity and/or debt investment held	148,025	148,025
Debt assumed	$ 1,162,379	1,162,379
Economic interest (as a percent)	49.65%
Value of interest	$ 1,585,000
Face amount of loan	1,450,000
Notional value	504,000
Total fixed rate debt							$ 500,000
Purchase price fair value adjustment	71,400	$ 71,446
388-390 Greenwich Street | Scenario, Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land	558,700
Building and building leasehold	$ 1,000,000
102 Greene Street, 635 Madison Avenue, 719 Seventh Avenue, 115 Spring Street, and 388-390 Greenwich Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Impact to rental revenue for amortization of aggregate below-market leases												7,600
Impact to depreciation expense												$ 10,300

Property Acquisitions - Pro For

Property Acquisitions - Pro Forma (Details) - 11 Madison Avenue - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property Acquisitions
Actual revenues since acquisition	$ 9,051		$ 9,051
Actual net income since acquisition	(4,202)		(4,202)
Pro forma revenues	432,822	$ 397,684	1,255,507	$ 1,146,697
Pro forma income from continuing operations	$ 25,299	$ 31,197	$ 26,645	$ 350,125
Pro forma basic earnings per share (in usd per share)	$ 0.18	$ 0.59	$ 0.11	$ 6.39
Pro forma diluted earnings per share (in usd per share)	0.18	0.59	0.11	6.36
SL Green Operating Partnership
Property Acquisitions
Pro forma basic earnings per share (in usd per share)	0.18	0.59	0.11	6.39
Pro forma diluted earnings per share (in usd per share)	$ 0.18	$ 0.59	$ 0.11	$ 6.36
Mortgage loan
Property Acquisitions
Fixed rate debt	$ 1,400,000	$ 1,400,000	$ 1,400,000	$ 1,400,000
Term (in Years)	10 years	10 years	10 years	10 years
Interest rate, fixed rate debt (as a percent)	3.838%	3.838%	3.838%	3.838%

Property Acquisitions - Schedul

Property Acquisitions - Schedule of Fair Value of Equity Interest Immediately Before Acquisition Date (Details) - 388-390 Greenwich Street - USD ($) $ in Thousands	May. 15, 2014	May. 14, 2014
Property Acquisitions
Contract purchase price	$ 1,584,868	$ 1,585,000
Net consideration funded by us at closing, excluding consideration financed by debt	(208,614)	(208,614)
Debt assumed	(1,162,379)	(1,162,379)
Fair value of retained equity interest		214,007
Equity and/or debt investment held	(148,025)	(148,025)
Other		5,464
Purchase price fair value adjustment	$ 71,400	$ 71,446

Properties Held for Sale and 63

Properties Held for Sale and Property Dispositions - Properties Held for Sale (Details) $ in Millions	3 Months Ended
	Sep. 30, 2015USD ($)
570-574 Fifth Avenue
Property Dispositions and Assets Held for Sale
Agreed sale consideration	$ 125.4
140-150 Grand Street
Property Dispositions and Assets Held for Sale
Agreed sale consideration	32
Impairment Charge	$ 19.2

Properties Held for Sale and 64

Properties Held for Sale and Property Dispositions - Property Dispositions (Details) $ in Thousands	1 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)ft²	Aug. 31, 2015USD ($)ft²	Jan. 31, 2015USD ($)ft²	Sep. 30, 2015USD ($)ft²	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)ft²	Sep. 30, 2014USD ($)
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²	35,843,296			35,843,296		35,843,296
Gain on Sale				$ 0	$ 29,507	$ 12,983	$ 144,242
Revenues
Rental revenue				0	9,504	236	44,676
Escalation and reimbursement revenues				0	(194)	(127)	4,413
Other income				0	0	0	21
Total revenues				0	9,310	109	49,110
Operating expenses				0	773	(631)	7,101
Real estate taxes				0	787	250	6,618
Ground rent				0	0	0	3,001
Transaction related costs				0	115	(49)	155
Interest expense, net of interest income				0	2,874	109	10,983
Amortization of deferred financing costs				0	48	3	369
Depreciation and amortization				0	678	0	5,434
Total expenses				0	5,275	(318)	33,661
Net income from discontinued operations				$ 0	$ 4,035	$ 427	$ 15,449
180 Maiden Lane
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²			1,090,000
Sales Price			$ 470,000
Gain on Sale			$ 17,000
131-137 Spring Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²		68,342
Sales Price		$ 277,800
Gain on Sale		$ 101,100
Ownership percentage in disposed asset		80.00%
120 West 45th Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²	440,000			440,000		440,000
Sales Price	$ 365,000
Gain on Sale	$ 58,600

Debt and Preferred Equity Inv65

Debt and Preferred Equity Investments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Debt investment
Increase in debt and preferred equity investments (net of discounts), including investments classified as held-for-sale	$ 464,900	$ 476,600
Decrease in debt and preferred equity investments (net of discounts), including investments classified as held-for-sale	$ 372,100	348,500
Aggregate weighted average current yield (as a percent)	10.32%
Debt Investments Held [Abstract]
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,501,619		$ 1,408,804
Debt investment
Debt Investments Held [Abstract]
Future Funding Obligations	110,176
Senior Financing	5,653,399
Carrying Value, Net of Discounts and Deferred Origination Fees	1,459,470		1,275,809
Total fixed rate
Debt Investments Held [Abstract]
Future Funding Obligations	155
Senior Financing	2,853,100
Carrying Value, Net of Discounts and Deferred Origination Fees	556,559		582,174
Total fixed rate | Junior Mortgage Participation/Mezzanine Loan, February 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	205,000
Carrying Value, Net of Discounts and Deferred Origination Fees	72,541		70,688
Total fixed rate | Junior Mortgage Participation/Mezzanine Loan, May 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	23,371		45,611
Total fixed rate | Junior Mortgage Participation, June 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	133,000
Carrying Value, Net of Discounts and Deferred Origination Fees	49,000		49,000
Total fixed rate | Mezzanine Loan, November 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	165,000
Carrying Value, Net of Discounts and Deferred Origination Fees	72,031		71,656
Total fixed rate | Junior Mortgage Participation/Mezzanine Loan, March 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	1,109,000
Carrying Value, Net of Discounts and Deferred Origination Fees	102,709		98,934
Total fixed rate | Mezzanine Loan, March 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	66,075		65,770
Total fixed rate | Mezzanine Loan, June 2017
Debt Investments Held [Abstract]
Future Funding Obligations	155
Senior Financing	502,100
Carrying Value, Net of Discounts and Deferred Origination Fees	40,938		24,608
Amount participated out	41,300
Total fixed rate | Mezzanine Loan, July 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	539,000
Carrying Value, Net of Discounts and Deferred Origination Fees	49,666		49,629
Total fixed rate | Mortgage Loan, February 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	26,249		26,209
Loan acquired		26,400
Discount amount		200
Total fixed rate | Mortgage Loan, August 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	545		637
Total fixed rate | Mezzanine Loan, September 2021
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	15,000
Carrying Value, Net of Discounts and Deferred Origination Fees	3,500		3,500
Total fixed rate | Mezzanine Loan, November 2023
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	90,000
Carrying Value, Net of Discounts and Deferred Origination Fees	19,934		19,930
Amount participated out	5,000
Total fixed rate | Mezzanine Loan, January 2025
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	95,000
Carrying Value, Net of Discounts and Deferred Origination Fees	30,000		30,000
Total fixed rate | Mezzanine Loan Repaid in February 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	0		14,068
Total fixed rate | Junior Mortgage Participation Repaid in March 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	0		11,934
Total fixed rate | Junior Mortgage Participation, Sold July 2015
Debt Investments Held [Abstract]
Carrying amount of Notes	22,900
Total fixed rate | Junior Mortgage Participation, Related To Mortgage Loan, February 2019
Debt Investments Held [Abstract]
Loan acquired		5,700
Discount amount		$ 5,700
Total floating rate
Debt Investments Held [Abstract]
Future Funding Obligations	110,021
Senior Financing	2,800,299
Carrying Value, Net of Discounts and Deferred Origination Fees	902,911		693,635
Total floating rate | Mezzanine Loan, November 2016
Debt Investments Held [Abstract]
Future Funding Obligations	9,726
Senior Financing	304,610
Carrying Value, Net of Discounts and Deferred Origination Fees	64,430		0
Total floating rate | Mezzanine Loan, March 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	775,000
Carrying Value, Net of Discounts and Deferred Origination Fees	74,349		73,402
Total floating rate | Mortgage/Mezzanine Loan, April 2016
Debt Investments Held [Abstract]
Future Funding Obligations	14,981
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	81,730		0
Total floating rate | Mezzanine Loan, June 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	160,000
Carrying Value, Net of Discounts and Deferred Origination Fees	22,612		22,573
Amount participated out	7,400
Total floating rate | Jr Mortgage Participation, July 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	30,000
Carrying Value, Net of Discounts and Deferred Origination Fees	15,000		0
Total floating rate | Mezzanine Loan, July 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	115,000
Carrying Value, Net of Discounts and Deferred Origination Fees	24,914		24,910
Total floating rate | Mezzanine Loan, September 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	110,000
Carrying Value, Net of Discounts and Deferred Origination Fees	50,000		49,614
Total floating rate | Mezzanine Loan, November 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	360,000
Carrying Value, Net of Discounts and Deferred Origination Fees	99,398		99,023
Total floating rate | Mezzanine Loan, December 2016
Debt Investments Held [Abstract]
Future Funding Obligations	12,885
Senior Financing	127,824
Carrying Value, Net of Discounts and Deferred Origination Fees	48,226		42,750
Total floating rate | Mezzanine Loan, December 2016
Debt Investments Held [Abstract]
Future Funding Obligations	461
Senior Financing	38,687
Carrying Value, Net of Discounts and Deferred Origination Fees	13,539		11,835
Total floating rate | Mortgage/Mezzanine Loan, January 2017
Debt Investments Held [Abstract]
Future Funding Obligations	66,314
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	124,789		0
Amount participated out	25,000
Total floating rate | Mezzanine Loan, January 2017
Debt Investments Held [Abstract]
Future Funding Obligations	1,851
Senior Financing	118,718
Carrying Value, Net of Discounts and Deferred Origination Fees	27,956		20,651
Total floating rate | Jr. Mortgage Participation/Mezzanine Loan, July 2017
Debt Investments Held [Abstract]
Future Funding Obligations	1,508
Senior Financing	117,460
Carrying Value, Net of Discounts and Deferred Origination Fees	40,034		38,524
Total floating rate | Mortgage/Mezzanine Loan, July 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	22,858		22,803
Total floating rate | Mortgage/Mezzanine Loan, September 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	16,887		16,848
Total floating rate | Mezzanine Loan, November 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	60,000
Carrying Value, Net of Discounts and Deferred Origination Fees	14,892		14,859
Total floating rate | Mortgage Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Future Funding Obligations	795
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	14,917		14,845
Amount participated out	5,100
Total floating rate | Junior Mortgage Participation Loan, April 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	40,000
Carrying Value, Net of Discounts and Deferred Origination Fees	19,830		0
Total floating rate | Mezzanine Loan, April 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	350,000
Carrying Value, Net of Discounts and Deferred Origination Fees	34,698		0
Total floating rate | Junior Mortgage Participation/Mezzanine Loan, July 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	55,000
Carrying Value, Net of Discounts and Deferred Origination Fees	20,516		20,533
Total floating rate | Mortgage/Mezzanine Loan, August 2018
Debt Investments Held [Abstract]
Future Funding Obligations	1,500
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	31,185		0
Total floating rate | Mortgage/Mezzanine Loan, February 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	18,316		18,083
Total floating rate | Mezzanine Loan, March 2019
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	38,000
Carrying Value, Net of Discounts and Deferred Origination Fees	21,835		21,807
Total floating rate | Mezzanine Loan, Repaid April 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	0		33,726
Total floating rate | Mezzanine Loan, Repaid April 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	0		37,322
Total floating rate | Mortgage/Mezzanine Loan Repaid in August 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 0		$ 109,527

Debt and Preferred Equity Inv66

Debt and Preferred Equity Investments (Details 2) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Preferred equity investment
Aggregate weighted average current yield (as a percent)	10.32%
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,501,619	$ 1,408,804
Preferred equity investments
Preferred equity investment
Aggregate weighted average current yield (as a percent)	7.77%
Future Funding Obligations	$ 5,580
Senior Financing	130,387
Carrying Value, Net of Discounts and Deferred Origination Fees	42,149	132,995
Preferred Equity, March 2018
Preferred equity investment
Future Funding Obligations	0
Senior Financing	70,000
Carrying Value, Net of Discounts and Deferred Origination Fees	9,964	9,954
Preferred Equity, November 2018
Preferred equity investment
Future Funding Obligations	5,580
Senior Financing	60,387
Carrying Value, Net of Discounts and Deferred Origination Fees	32,185	0
Preferred Equity, Redeemed July 2015
Preferred equity investment
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 0	$ 123,041

Debt and Preferred Equity Inv67

Debt and Preferred Equity Investments (Details 3) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)segment	Dec. 31, 2014USD ($)segment
Investments, Debt and Equity Securities [Abstract]
Number of portfolio segments of financial receivables (segment) | segment	1	1
Additional amount of financing receivables included in other assets	$ 115.5	$ 133.5

Investments in Unconsolidated68

Investments in Unconsolidated Joint Ventures (Details) $ in Thousands	1 Months Ended					3 Months Ended		9 Months Ended
	Oct. 31, 2015USD ($)	Aug. 31, 2015USD ($)ft²	Jul. 31, 2015USD ($)	Mar. 31, 2015USD ($)	Feb. 28, 2015USD ($)property	Sep. 30, 2015USD ($)ft²unit	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)ft²unit	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
General information on each joint venture
Net equity investment in VIEs in which the entity is not primary beneficiary						$ 100,200		$ 100,200		$ 146,200
Approximate Square Feet (sqft) | ft²						35,843,296		35,843,296
Loans Receivable, Gross, Commercial, Acquisition						$ 145,763		$ 145,763		145,875
Gain (Loss) on Sale						$ 0	$ 29,507	$ 12,983	$ 144,242
100 Park Avenue
General information on each joint venture
Ownership Interest (as a percent)						49.90%		49.90%
Economic Interest (as a percent)						49.90%		49.90%
Approximate Square Feet (sqft) | ft²						834,000		834,000
Acquisition Price						$ 95,800		$ 95,800
717 Fifth Avenue
General information on each joint venture
Ownership Interest (as a percent)						10.92%		10.92%
Economic Interest (as a percent)						10.92%		10.92%
Approximate Square Feet (sqft) | ft²						119,500		119,500
Acquisition Price						$ 251,900		$ 251,900
800 Third Avenue
General information on each joint venture
Ownership Interest (as a percent)						60.52%		60.52%
Economic Interest (as a percent)						60.52%		60.52%
Approximate Square Feet (sqft) | ft²						526,000		526,000
Acquisition Price						$ 285,000		$ 285,000
Additional Ownership Percentage Acquired (less than for the 1.0%)				17.56%
Additional Cost for additional interest in joint venture				$ 67,500
1745 Broadway
General information on each joint venture
Ownership Interest (as a percent)						56.88%		56.88%
Economic Interest (as a percent)						56.88%		56.88%
Approximate Square Feet (sqft) | ft²						674,000		674,000
Acquisition Price						$ 520,000		$ 520,000
Jericho Plaza
General information on each joint venture
Ownership Interest (as a percent)						20.26%		20.26%
Economic Interest (as a percent)						20.26%		20.26%
Approximate Square Feet (sqft) | ft²						640,000		640,000
Acquisition Price						$ 210,000		$ 210,000
600 Lexington Avenue
General information on each joint venture
Ownership Interest (as a percent)						55.00%		55.00%
Economic Interest (as a percent)						55.00%		55.00%
Approximate Square Feet (sqft) | ft²						303,515		303,515
Acquisition Price						$ 193,000		$ 193,000
11 West 34th Street
General information on each joint venture
Ownership Interest (as a percent)						30.00%		30.00%
Economic Interest (as a percent)						30.00%		30.00%
Approximate Square Feet (sqft) | ft²						17,150		17,150
Acquisition Price						$ 10,800		$ 10,800
7 Renaissance
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Economic Interest (as a percent)						50.00%		50.00%
Approximate Square Feet (sqft) | ft²						65,641		65,641
Acquisition Price						$ 4,000		$ 4,000
3 Columbus Circle
General information on each joint venture
Ownership Interest (as a percent)						48.90%		48.90%
Economic Interest (as a percent)						48.90%		48.90%
Approximate Square Feet (sqft) | ft²						741,500		741,500
Acquisition Price						$ 500,000		$ 500,000
280 Park Avenue
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Economic Interest (as a percent)						50.00%		50.00%
Approximate Square Feet (sqft) | ft²						1,219,158		1,219,158
Acquisition Price						$ 400,000		$ 400,000
1552-1560 Broadway
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Economic Interest (as a percent)						50.00%		50.00%
Approximate Square Feet (sqft) | ft²						35,897		35,897
Acquisition Price						$ 136,550		$ 136,550
724 Fifth Avenue
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Economic Interest (as a percent)						50.00%		50.00%
Approximate Square Feet (sqft) | ft²						65,040		65,040
Acquisition Price						$ 223,000		$ 223,000
10 East 53rd Street
General information on each joint venture
Ownership Interest (as a percent)						55.00%		55.00%
Economic Interest (as a percent)						55.00%		55.00%
Approximate Square Feet (sqft) | ft²						354,300		354,300
Acquisition Price						$ 252,500		$ 252,500
33 Beekman
General information on each joint venture
Ownership Interest (as a percent)						45.90%		45.90%
Economic Interest (as a percent)						45.90%		45.90%
Approximate Square Feet (sqft) | ft²						163,500		163,500
Acquisition Price						$ 31,000		$ 31,000
521 Fifth Avenue
General information on each joint venture
Ownership Interest (as a percent)						50.50%		50.50%
Economic Interest (as a percent)						50.50%		50.50%
Approximate Square Feet (sqft) | ft²						460,000		460,000
Acquisition Price						$ 315,000		$ 315,000
21 East 66th Street
General information on each joint venture
Ownership Interest (as a percent)						32.28%		32.28%
Economic Interest (as a percent)						32.28%		32.28%
Approximate Square Feet (sqft) | ft²						16,736		16,736
Acquisition Price						$ 75,000		$ 75,000
650 Fifth Avenue
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Economic Interest (as a percent)						50.00%		50.00%
Approximate Square Feet (sqft) | ft²						32,324		32,324
Acquisition Price						$ 0		$ 0
121 Greene Street
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Economic Interest (as a percent)						50.00%		50.00%
Approximate Square Feet (sqft) | ft²						7,131		7,131
Acquisition Price						$ 27,400		$ 27,400
175-225 Third Street Brooklyn, New York
General information on each joint venture
Ownership Interest (as a percent)						95.00%		95.00%
Economic Interest (as a percent)						95.00%		95.00%
Approximate Square Feet (sqft) | ft²						0		0
Acquisition Price						$ 74,600		$ 74,600
55 West 46th Street
General information on each joint venture
Ownership Interest (as a percent)						25.00%		25.00%
Economic Interest (as a percent)						25.00%		25.00%
Approximate Square Feet (sqft) | ft²						347,000		347,000
Acquisition Price						$ 295,000		$ 295,000
Stonehenge Portfolio
General information on each joint venture
Approximate Square Feet (sqft) | ft²						2,046,733		2,046,733
Acquisition Price					$ 40,200	$ 36,668		$ 36,668
Additional Ownership Percentage Acquired (less than for the 1.0%)			1.00%
Additional Cost for additional interest in joint venture			$ 1,100
Increase in real estate investment ownership interest					$ 3,500
Number of Joint Venture Properties with an Increased Ownership Interest | property					6
131-137 Spring Street
General information on each joint venture
Ownership Interest (as a percent)						20.00%		20.00%
Economic Interest (as a percent)						20.00%		20.00%
Approximate Square Feet (sqft) | ft²						68,342		68,342
Acquisition Price						$ 277,750		$ 277,750
1552 Broadway
General information on each joint venture
Approximate Square Feet (sqft) | ft²						13,045		13,045
Three Retail and Two Residential Units | 21 East 66th Street
General information on each joint venture
Ownership Interest (as a percent)						32.28%		32.28%
Number of Stores | unit						3		3
Number Of Residential Units | unit						2		2
Three Residential Units | 21 East 66th Street
General information on each joint venture
Ownership Interest (as a percent)						16.14%		16.14%
Number Of Residential Units | unit						3		3
Series M Preferred Units
General information on each joint venture
Preferred Units (as a percent)					3.75%
Series M Preferred Units | Stonehenge Portfolio
General information on each joint venture
Issuance of aggregate liquidation preference of preferred units					$ 40,000
Mezzanine loan and preferred equity due March 2016
General information on each joint venture
Loans Receivable, Gross, Commercial, Acquisition						$ 99,856		$ 99,856		99,629
Mezzanine loan due February 2022
General information on each joint venture
Loans Receivable, Gross, Commercial, Acquisition						$ 45,907		$ 45,907		$ 46,246
Subsequent Event | 33 Beekman
General information on each joint venture
Agreed sale consideration	$ 196,000
131-137 Spring Street
General information on each joint venture
Approximate Square Feet (sqft) | ft²		68,342
Agreed sale consideration		$ 277,800
Gain (Loss) on Sale		$ 101,100
Ownership percentage in disposed asset		80.00%
The Meadows
General information on each joint venture
Ownership Interest (as a percent)						50.00%		50.00%
Gross Asset Valuation						$ 121,100		$ 121,100
Gain (Loss) on Sale								$ (1,600)
315 West 36th Street
General information on each joint venture
Ownership Interest (as a percent)						35.50%		35.50%
Gross Asset Valuation						$ 115,000		$ 115,000
Gain (Loss) on Sale								$ 16,300

Investments in Unconsolidated69

Investments in Unconsolidated Joint Ventures (Details 2) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Debt Instrument [Line Items]
Total fixed rate debt	$ 5,824,875		$ 5,824,875		$ 5,824,875		$ 4,736,709
Total floating rate debt	1,040,508		1,040,508		1,040,508		1,103,942
Total fixed rate and floating rate debt	6,865,383		6,865,383		6,865,383		5,840,651
Gain (loss) on early extinguishment of debt		$ (800)	0	$ (24,475)	(49)	$ (25,500)
1745 Broadway
Debt Instrument [Line Items]
Total fixed rate debt	16,000		16,000		16,000		16,000
315 West 36th Street
Debt Instrument [Line Items]
Agreed sale consideration	115,000
Joint venture
Debt Instrument [Line Items]
Total fixed rate debt	2,826,904		2,826,904		2,826,904		2,065,264
Total floating rate debt	1,586,898		1,586,898		1,586,898		1,713,440
Total fixed rate and floating rate debt	4,413,802		4,413,802		4,413,802		3,778,704
Maximum amount of loan recourse to entity	18,400		18,400		18,400
Joint venture | 7 Renaissance
Debt Instrument [Line Items]
Total fixed rate debt	2,927		2,927		2,927		2,147
Joint venture | 11 West 34th Street
Debt Instrument [Line Items]
Total fixed rate debt	16,671		16,671		16,671		16,905
Joint venture | 280 Park Avenue
Debt Instrument [Line Items]
Total fixed rate debt	694,846		694,846		694,846		700,171
Joint venture | 1745 Broadway
Debt Instrument [Line Items]
Total fixed rate debt	340,000		340,000		340,000		340,000
Joint venture | Jericho Plaza
Debt Instrument [Line Items]
Total fixed rate debt	163,750		163,750		163,750		163,750
Joint venture | 800 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt	20,910		20,910		20,910		20,910
Joint venture | 521 Fifth Avenue
Debt Instrument [Line Items]
Total fixed rate debt	170,000		170,000		170,000		170,000
Joint venture | 717 Fifth Avenue | Mortgage loan
Debt Instrument [Line Items]
Committed amount	300,000		300,000		300,000
Joint venture | 717 Fifth Avenue | Mezzanine loans
Debt Instrument [Line Items]
Committed amount	290,000		290,000		290,000
Joint venture | 21 East 66th Street
Debt Instrument [Line Items]
Total fixed rate debt	12,000		12,000		12,000		12,000
Total floating rate debt	1,825		1,825		1,825		1,883
Joint venture | 3 Columbus Circle
Debt Instrument [Line Items]
Total fixed rate debt	350,000		350,000		350,000		0
Total floating rate debt	0		0		0		230,974
Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	433,031		433,031		433,031		0
Total floating rate debt	10,500		10,500		10,500		0
Joint venture | 315 West 36th Street
Debt Instrument [Line Items]
Total fixed rate debt	0		0		0		25,000
Joint venture | 1552 Broadway
Debt Instrument [Line Items]
Total floating rate debt	188,409		188,409		188,409		184,210
Joint venture | 1552 Broadway | Mortgage loan
Debt Instrument [Line Items]
Committed amount	150,000		150,000		150,000
Unfunded amount	1,700		1,700		1,700
Joint venture | 1552 Broadway | Mezzanine loans
Debt Instrument [Line Items]
Committed amount	41,500		41,500		41,500
Unfunded amount	1,400		1,400		1,400
Joint venture | Other loan payable
Debt Instrument [Line Items]
Total floating rate debt	30,000		30,000		30,000		30,000
Joint venture | 650 Fifth Avenue
Debt Instrument [Line Items]
Total floating rate debt	65,000		65,000		65,000		65,000
Joint venture | 650 Fifth Avenue | Mortgage loan
Debt Instrument [Line Items]
Committed amount	97,000		97,000		97,000
Unfunded amount	32,000		32,000		32,000
Joint venture | 175-225 Third Street Brooklyn, New York
Debt Instrument [Line Items]
Total floating rate debt	40,000		40,000		40,000		40,000
Joint venture | 10 East 53rd Street
Debt Instrument [Line Items]
Total floating rate debt	125,000		125,000		125,000		125,000
Joint venture | 724 Fifth Avenue
Debt Instrument [Line Items]
Total floating rate debt	275,000		275,000		275,000		275,000
Joint venture | 33 Beekman
Debt Instrument [Line Items]
Total floating rate debt	71,378		71,378		71,378		52,283
Maximum amount of loan recourse to entity	75,000		75,000		75,000
Joint venture | 600 Lexington Avenue
Debt Instrument [Line Items]
Total floating rate debt	113,786		113,786		113,786		116,740
Joint venture | 55 West 46th Street
Debt Instrument [Line Items]
Total floating rate debt	150,000		150,000		150,000		150,000
Joint venture | 55 West 46th Street | Mortgage loan
Debt Instrument [Line Items]
Committed amount	190,000		190,000		190,000
Unfunded amount	40,000		40,000		40,000
Joint venture | 121 Greene Street
Debt Instrument [Line Items]
Total floating rate debt	15,000		15,000		15,000		15,000
Joint venture | 131-137 Spring Street
Debt Instrument [Line Items]
Total floating rate debt	141,000		141,000		141,000		0
Joint venture | 100 Park Avenue
Debt Instrument [Line Items]
Total floating rate debt	360,000		360,000		360,000		360,000
Joint venture | The Meadows
Debt Instrument [Line Items]
Total floating rate debt	0		0		0		67,350
Initial Maturity July 2022 | Joint venture | 717 Fifth Avenue
Debt Instrument [Line Items]
Total fixed rate debt	300,000		300,000		300,000		300,000
Initial Maturity July 2024 | Joint venture | 717 Fifth Avenue
Debt Instrument [Line Items]
Total fixed rate debt	322,769		322,769		322,769		$ 314,381
Initial Maturity July 2016 | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	13,400		13,400		13,400
Initial Maturity June 2017 | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	55,800		55,800		55,800
Initial Maturity November 2017 | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	35,000		35,000		35,000
Initial Maturity February 2018 | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	7,400		7,400		7,400
Initial Maturity August 2019 | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	142,100		142,100		142,100
Initial Maturity June 2024 | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt	$ 179,400		$ 179,400		$ 179,400
Weighted Average | 1745 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.81%		4.81%		4.81%
Weighted Average | Joint venture | 7 Renaissance
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	10.00%		10.00%		10.00%
Weighted Average | Joint venture | 11 West 34th Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.82%		4.82%		4.82%
Weighted Average | Joint venture | 280 Park Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	6.57%		6.57%		6.57%
Weighted Average | Joint venture | 1745 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.68%		5.68%		5.68%
Weighted Average | Joint venture | Jericho Plaza
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.65%		5.65%		5.65%
Weighted Average | Joint venture | 800 Third Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	6.00%		6.00%		6.00%
Weighted Average | Joint venture | 521 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.73%		3.73%		3.73%
Weighted Average | Joint venture | 21 East 66th Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.60%		3.60%		3.60%
Interest rate, floating rate debt (as a percent)	3.00%		3.00%		3.00%
Weighted Average | Joint venture | 3 Columbus Circle
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.61%		3.61%		3.61%
Weighted Average | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.18%		4.18%		4.18%
Interest rate, floating rate debt (as a percent)	3.25%		3.25%		3.25%
Weighted Average | Joint venture | 1552 Broadway
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	4.32%		4.32%		4.32%
Weighted Average | Joint venture | Other loan payable
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.09%		1.09%		1.09%
Weighted Average | Joint venture | 650 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	3.70%		3.70%		3.70%
Weighted Average | Joint venture | 175-225 Third Street Brooklyn, New York
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	4.25%		4.25%		4.25%
Weighted Average | Joint venture | 10 East 53rd Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	2.70%		2.70%		2.70%
Weighted Average | Joint venture | 724 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	2.62%		2.62%		2.62%
Weighted Average | Joint venture | 33 Beekman
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	2.94%		2.94%		2.94%
Weighted Average | Joint venture | 600 Lexington Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	2.29%		2.29%		2.29%
Weighted Average | Joint venture | 55 West 46th Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	2.50%		2.50%		2.50%
Weighted Average | Joint venture | 121 Greene Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.70%		1.70%		1.70%
Weighted Average | Joint venture | 131-137 Spring Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.75%		1.75%		1.75%
Weighted Average | Joint venture | 100 Park Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.95%		1.95%		1.95%
Weighted Average | Initial Maturity July 2022 | Joint venture | 717 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.45%		4.45%		4.45%
Weighted Average | Initial Maturity July 2024 | Joint venture | 717 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	9.00%		9.00%		9.00%

Investments in Unconsolidated70

Investments in Unconsolidated Joint Ventures (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Assets
Commercial real estate property, net	$ 14,261,102		$ 14,261,102		$ 12,163,976
Other assets	912,023		912,023		647,333
Liabilities and members' equity
Mortgages and other loans payable	6,865,383		6,865,383		5,586,709
Company's investments in unconsolidated joint ventures	1,239,008		1,239,008		1,172,020
Combined statements of income for the unconsolidated joint ventures
Operating expenses	78,648	$ 72,111	225,539	$ 211,118
Ground rent	8,252	8,088	24,526	24,161
Real estate taxes	61,009	55,548	173,018	159,702
Interest expense, net of interest income	84,141	82,376	235,694	236,424
Amortization of deferred financing costs	7,160	6,679	19,727	15,737
Transaction related costs	5,829	2,383	10,039	6,554
Depreciation and amortization	146,185	94,443	454,087	274,337
Total expenses	414,699	344,277	1,214,769	997,811
Company's equity in net income from unconsolidated joint ventures	3,627	6,034	10,651	20,781
Joint venture
Assets
Commercial real estate property, net	6,282,267		6,282,267		5,275,632
Other assets	906,955		906,955		810,567
Total assets	7,189,222		7,189,222		6,086,199
Liabilities and members' equity
Mortgages and other loans payable	4,413,802		4,413,802		3,778,704
Other liabilities	501,637		501,637		485,572
Members' equity	2,273,783		2,273,783		1,821,923
Total liabilities and members' equity	7,189,222		7,189,222		6,086,199
Company's investments in unconsolidated joint ventures	1,239,008		1,239,008		$ 1,172,020
Combined statements of income for the unconsolidated joint ventures
Total revenues	150,638	114,831	423,089	406,464
Operating expenses	27,647	18,530	79,478	63,575
Ground rent	4,677	2,638	9,841	7,295
Real estate taxes	23,494	15,867	65,205	48,209
Interest expense, net of interest income	51,430	40,885	147,152	137,949
Amortization of deferred financing costs	3,473	2,837	9,628	9,496
Transaction related costs	604	501	615	565
Depreciation and amortization	38,144	28,324	109,022	107,786
Total expenses	149,469	109,582	420,941	374,875
Loss on early extinguishment of debt	(248)	0	(1,081)	(6,743)
Net income before gain on sale	921	5,249	1,067	24,846
Company's equity in net income from unconsolidated joint ventures	3,627	6,034	10,651	20,781
Joint venture
Investment in Unconsolidated Joint Ventures
Management fees, base revenue	$ 1,900	$ 3,800	$ 6,800	$ 15,000

Deferred Costs (Details)

Deferred Costs (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing	$ 405,278	$ 385,555
Deferred financing	211,552	193,776
Deferred costs, gross	616,830	579,331
Less accumulated amortization	(273,894)	(251,369)
Deferred costs, net	$ 342,936	$ 327,962

Mortgages and Other Loans Pay72

Mortgages and Other Loans Payable (Details) - USD ($)	Sep. 30, 2015	Sep. 30, 2015	Feb. 28, 2015	Jan. 31, 2015	Dec. 31, 2014	Oct. 31, 2014
Debt Instrument [Line Items]
Total fixed rate debt	$ 5,824,875,000	$ 5,824,875,000			$ 4,736,709,000
Total floating rate debt	1,040,508,000	1,040,508,000			1,103,942,000
Total fixed rate and floating rate debt	6,865,383,000	6,865,383,000			5,840,651,000
Mortgages reclassed to liabilities related to assets held for sale	0	0			(253,942,000)
Total mortgages and other loans payable	6,865,383,000	6,865,383,000			5,586,709,000
Federal Home Loan Bank Advances outstanding	$ 6,000,000	$ 6,000,000
Federal Home Loan Bank, advances, weighted-average borrowing rate (as a percent)	0.52%	0.52%
Book value of collateral	$ 10,500,000,000	$ 10,500,000,000			8,200,000,000
Series J Preferred Stock
Debt Instrument [Line Items]
Total fixed rate debt	4,000,000	4,000,000			4,000,000
Temporary Equity, Carrying Amount, Attributable to Noncontrolling Interest	$ 4,000,000	$ 4,000,000
Preferred units, shares outstanding	4,000	4,000
Preferred Units (as a percent)		3.75%
Preferred Units, liquidation preference (in dollars per unit)	$ 1,000	$ 1,000
FHLB Facility
Debt Instrument [Line Items]
Total fixed rate debt	$ 1,000,000	$ 1,000,000			0
Total floating rate debt	5,000,000	5,000,000			0
Master Repurchase Agreement
Debt Instrument [Line Items]
Total floating rate debt	285,508,000	285,508,000			100,000,000
Maximum facility capacity	$ 300,000,000	300,000,000
Basis Point Fee (as a percent)	0.25%
Threshold amount for basis point fee to be applicable (less than)	$ 150,000,000
500 West Putnam Avenue
Debt Instrument [Line Items]
Total fixed rate debt	22,527,000	22,527,000			22,968,000
Landmark Square
Debt Instrument [Line Items]
Total fixed rate debt	79,995,000	79,995,000			81,269,000
485 Lexington Avenue
Debt Instrument [Line Items]
Total fixed rate debt	450,000,000	450,000,000			450,000,000
762 Madison Avenue
Debt Instrument [Line Items]
Total fixed rate debt	7,916,000	7,916,000			8,045,000
885 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt	267,650,000	267,650,000			267,650,000
1745 Broadway
Debt Instrument [Line Items]
Total fixed rate debt	16,000,000	16,000,000			16,000,000
388-390 Greenwich Street
Debt Instrument [Line Items]
Total fixed rate debt	1,004,000,000	1,004,000,000			1,004,000,000
Total floating rate debt	446,000,000	446,000,000			446,000,000
388-390 Greenwich Street | Swap One
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)						3.80%
Total fixed rate debt						$ 504,000,000
388-390 Greenwich Street | Swap Two
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)						2.69%
Total fixed rate debt						$ 500,000,000
One Madison Avenue
Debt Instrument [Line Items]
Total fixed rate debt	548,699,000	548,699,000			565,742,000
100 Church Street
Debt Instrument [Line Items]
Total fixed rate debt	226,000,000	226,000,000			228,612,000
919 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt	$ 500,000,000	$ 500,000,000			500,000,000
Interest in property (as a percent)	51.00%	51.00%
400 East 57th Street
Debt Instrument [Line Items]
Total fixed rate debt	$ 67,962,000	$ 67,962,000			68,896,000
400 East 58th Street
Debt Instrument [Line Items]
Total fixed rate debt	29,126,000	29,126,000			29,527,000
420 Lexington Avenue
Debt Instrument [Line Items]
Total fixed rate debt	300,000,000	300,000,000			300,000,000
1515 Broadway
Debt Instrument [Line Items]
Total fixed rate debt	900,000,000	900,000,000			900,000,000
11 Madison Avenue
Debt Instrument [Line Items]
Total fixed rate debt	1,400,000,000	1,400,000,000			0
711 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt	0	0			120,000,000
120 West 45th Street
Debt Instrument [Line Items]
Total fixed rate debt	0	0			170,000,000
248-252 Bedford Avenue
Debt Instrument [Line Items]
Total floating rate debt	29,000,000	29,000,000			29,000,000
220 East 42nd Street
Debt Instrument [Line Items]
Total floating rate debt	275,000,000	275,000,000			275,000,000
180 Maiden Lane
Debt Instrument [Line Items]
Total floating rate debt	$ 0	$ 0			$ 253,942,000
Weighted Average | Series J Preferred Stock
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.75%	3.75%
Weighted Average | FHLB Facility
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	0.46%	0.46%
Interest rate, floating rate debt (as a percent)	0.53%	0.53%
Weighted Average | Master Repurchase Agreement
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	3.35%	3.35%
Weighted Average | 500 West Putnam Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.52%	5.52%
Weighted Average | Landmark Square
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.00%	4.00%
Weighted Average | 485 Lexington Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.61%	5.61%
Weighted Average | 762 Madison Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.86%	3.86%	3.86%	3.75%
Weighted Average | 885 Third Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	6.26%	6.26%
Weighted Average | 1745 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.81%	4.81%
Weighted Average | 388-390 Greenwich Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.25%	3.25%
Interest rate, floating rate debt (as a percent)	1.94%	1.94%
Weighted Average | One Madison Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.91%	5.91%
Weighted Average | 100 Church Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.68%	4.68%
Weighted Average | 919 Third Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.12%	5.12%
Weighted Average | 400 East 57th Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.13%	4.13%
Weighted Average | 400 East 58th Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.13%	4.13%
Weighted Average | 420 Lexington Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.99%	3.99%
Weighted Average | 1515 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.93%	3.93%
Weighted Average | 11 Madison Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.84%	3.84%
Weighted Average | 248-252 Bedford Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.70%	1.70%
Weighted Average | 220 East 42nd Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.80%	1.80%
LIBOR | Minimum | Master Repurchase Agreement
Debt Instrument [Line Items]
Credit facility, interest rate (as a percent)		2.50%
LIBOR | Maximum | Master Repurchase Agreement
Debt Instrument [Line Items]
Credit facility, interest rate (as a percent)		3.25%

Corporate Indebtedness (Details

Corporate Indebtedness (Details) - USD ($)	1 Months Ended				9 Months Ended
	Jul. 31, 2015	Jan. 31, 2015	Nov. 30, 2014	Mar. 31, 2014	Sep. 30, 2015	Dec. 31, 2014
Corporate Indebtedness
Increase in credit facility	$ 500,000,000
Outstanding under line of credit facility					$ 949,000,000	$ 385,000,000
Term loan
Corporate Indebtedness
Increase in credit facility	100,000,000		$ 50,000,000	$ 383,000,000
Credit facility, maximum borrowing capacity	933,000,000		$ 833,000,000	$ 783,000,000	$ 933,000,000
Decrease in basis points		0.20%		0.25%
Decrease in facility fee (as a percent)		0.05%
Effective rate (as a percent)					1.66%
Term loan | LIBOR
Corporate Indebtedness
Interest rate added to base rate (as a percent)					1.40%
Term loan | LIBOR | Minimum
Corporate Indebtedness
Interest rate added to base rate (as a percent)					0.95%
Term loan | LIBOR | Maximum
Corporate Indebtedness
Interest rate added to base rate (as a percent)					1.90%
Revolving credit facility
Corporate Indebtedness
Increase in credit facility	400,000,000
Credit facility, maximum borrowing capacity	$ 1,600,000,000				$ 1,600,000,000
Maximum borrowing capacity, optional expansion					$ 3,000,000,000
Effective rate (as a percent)					1.44%
Facility fee (as a percent)					0.25%
Outstanding under line of credit facility					$ 949,000,000
Revolving credit facility | Minimum
Corporate Indebtedness
Facility fee (as a percent)					0.10%
Revolving credit facility | Maximum
Corporate Indebtedness
Facility fee (as a percent)					0.00%
Revolving credit facility | LIBOR
Corporate Indebtedness
Interest rate added to base rate (as a percent)					1.25%
Revolving credit facility | LIBOR | Minimum
Corporate Indebtedness
Interest rate added to base rate (as a percent)					0.875%
Revolving credit facility | LIBOR | Maximum
Corporate Indebtedness
Interest rate added to base rate (as a percent)					1.55%
2012 Credit Facility
Corporate Indebtedness
Letters of credit					$ 81,200,000
Ability to borrow under line of credit facility					$ 569,800,000

Corporate Indebtedness (Detai74

Corporate Indebtedness (Details 2)	9 Months Ended
	Sep. 30, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 06, 2010USD ($)$ / shares	Mar. 20, 2007$ / shares
Debt disclosures by scheduled maturity date
Accreted Balance	$ 2,216,120,000	$ 2,107,078,000
Senior unsecured notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	1,310,316,000
Accreted Balance	1,283,120,000	1,274,078,000
Senior unsecured notes | 6.00% Senior unsecured notes maturing on March 31, 2016
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	255,308,000
Accreted Balance	$ 255,284,000	255,250,000
Coupon Rate (as a percent)	6.00%
Effective rate (as a percent)	6.00%
Term (in Years)	10 years
Senior unsecured notes | 3.00% Senior unsecured notes maturing on October 15, 2017
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 345,000,000
Accreted Balance	$ 318,035,000	309,069,000
Coupon Rate (as a percent)	3.00%
Effective rate (as a percent)	3.00%
Term (in Years)	7 years
Premium on sale price to calculate exchange price of notes (as a percent)			30.00%
Exchange price (in dollars per share) | $ / shares			$ 85.81
Adjusted exchange rate for the debentures (in shares)	12.2732
Principal amount of debentures, basis for conversion	$ 1,000
Amount of convertible debt recorded in equity			$ 78,300,000
Debt Instrument, Unamortized Discount	27,000,000
Senior unsecured notes | 5.00% Senior unsecured notes maturing on August 15, 2018
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	250,000,000
Accreted Balance	$ 249,793,000	249,744,000
Coupon Rate (as a percent)	5.00%
Effective rate (as a percent)	5.00%
Term (in Years)	7 years
Senior unsecured notes | 7.75% Senior unsecured notes maturing on March 15, 2020
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 250,000,000
Accreted Balance	$ 250,000,000	250,000,000
Coupon Rate (as a percent)	7.75%
Effective rate (as a percent)	7.75%
Term (in Years)	10 years
Senior unsecured notes | 4.50% Senior unsecured notes maturing on December 1, 2022
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 200,000,000
Accreted Balance	$ 200,000,000	200,000,000
Coupon Rate (as a percent)	4.50%
Effective rate (as a percent)	4.50%
Term (in Years)	10 years
Senior unsecured notes | 3.00% Senior unsecured notes maturing on March 30, 2027
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 10,008,000
Accreted Balance	$ 10,008,000	10,008,000
Coupon Rate (as a percent)	3.00%
Effective rate (as a percent)	3.00%
Term (in Years)	20 years
Premium on sale price to calculate exchange price of notes (as a percent)				25.00%
Exchange price (in dollars per share) | $ / shares				$ 173.30
Adjusted exchange rate for the debentures (in shares)	5.7952
Principal amount of debentures, basis for conversion	$ 1,000
Senior unsecured notes | Senior unsecured notes redeemed April 2015
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	0
Accreted Balance	$ 0	$ 7,000

Corporate Indebtedness (Detai75

Corporate Indebtedness (Details 3) - USD ($)	1 Months Ended	9 Months Ended
	Jun. 30, 2005	Sep. 30, 2015
Scheduled Amortization and Principal Repayments
Remaining 2,015		$ 8,716,000
2,016		693,487,000
2,017		1,141,400,000
2,018		330,462,000
2,019		1,031,726,000
Thereafter		6,951,908,000
Total amortization of debt and principal repayments		$ 10,157,699,000
Trust Preferred Securities
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 100,000,000
Coupon Rate (as a percent)		5.61%
Number of Years from Issuance of Debt for which Fixed Rate of Interest will be in Force		10 years
Scheduled Amortization and Principal Repayments
Remaining 2,015		$ 0
2,016		0
2,017		0
2,018		0
2,019		0
Thereafter		100,000,000
Total amortization of debt and principal repayments		100,000,000
Mortgages and other loans payable
Scheduled Amortization
Remaining 2,015		7,716,000
2,016		47,360,000
2,017		61,063,000
2,018		64,462,000
2,019		70,409,000
Thereafter		200,403,000
Total amortization of debt		451,413,000
Principal Repayments and Joint Venture Debt
Remaining 2,015		1,000,000
2,016		390,819,000
2,017		725,329,000
2,018		16,000,000
2,019		28,317,000
Thereafter		5,252,505,000
Total principal repayments		6,413,970,000
2012 Credit Facility
Scheduled Amortization and Principal Repayments
Remaining 2,015		0
2,016		0
2,017		0
2,018		0
2,019		0
Thereafter		949,000,000
Total amortization of debt and principal repayments		949,000,000
Unsecured Term Loan
Scheduled Amortization and Principal Repayments
Remaining 2,015		0
2,016		0
2,017		0
2,018		0
2,019		933,000,000
Thereafter		0
Total amortization of debt and principal repayments		933,000,000
Senior Unsecured Notes
Scheduled Amortization and Principal Repayments
Remaining 2,015		0
2,016		255,308,000
2,017		355,008,000
2,018		250,000,000
2,019		0
Thereafter		450,000,000
Total amortization of debt and principal repayments		1,310,316,000
Joint venture
Principal Repayments and Joint Venture Debt
Remaining 2,015		2,961,000
2,016		534,036,000
2,017		580,044,000
2,018		2,196,000
2,019		104,687,000
Thereafter		474,942,000
Total principal repayments		$ 1,698,866,000
LIBOR | Trust Preferred Securities
Debt Instrument [Line Items]
Interest rate added to base rate (as a percent)		1.25%
LIBOR | Unsecured Term Loan
Debt Instrument [Line Items]
Interest rate added to base rate (as a percent)		1.40%

Corporate Indebtedness (Detai76

Corporate Indebtedness (Details 4) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest expense
Interest expense	$ 84,917	$ 83,158	$ 237,847	$ 238,285
Interest income	(776)	(782)	(2,153)	(1,861)
Interest expense, net	84,141	82,376	235,694	236,424
Interest capitalized	$ 7,327	$ 7,972	$ 23,496	$ 18,689

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Amounts due from/to related parties
Due from joint ventures	$ 1,343		$ 1,343		$ 1,254
Other	9,746		9,746		10,481
Related party receivables	11,089		11,089		$ 11,735
Alliance Building Services
Related Party Transactions
Profit participation from related party	900	$ 900	2,900	$ 2,800
Payments made for services	5,700	5,900	14,300	14,700
Entity with Stephen L Green ownership interest
Related Party Transactions
Property management fees from related party	$ 100	$ 100	$ 400	$ 300

Noncontrolling Interests on t78

Noncontrolling Interests on the Company's Consolidated Financial Statements (Details)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2015shares	Jan. 31, 2012$ / sharesshares	Sep. 30, 2015USD ($)unit$ / sharesshares	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)unit$ / sharesshares	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)unit	Aug. 31, 2015shares	Jul. 31, 2015shares	Jun. 30, 2015shares	Aug. 31, 2014shares
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Balance at beginning of period | $					$ 469,524,000
Distributions | $					(114,828,000)
Redemption of common units | $					(20,650,000)
Net income | $			$ 6,467,000	$ 2,636,000	6,634,000	$ 16,010,000
Accumulated other comprehensive income allocation | $			(191,000)	$ 113,000	(349,000)	347,000
Balance at end of period | $			$ 423,421,000		$ 423,421,000		$ 469,524,000
Number of company common stock issued on conversion of Series B preferred units					6.71348
Series M Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Dividend rate preferred units (as a percent)	3.75%
SL Green Operating Partnership
Organization
Noncontrolling interest in the operating partnership (as a percent)			3.74%		3.74%		3.92%
Number of units of operating partnership owned by the noncontrolling interest unit holders (shares) | unit			3,874,750		3,874,750		3,973,016
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			3,874,750		3,874,750
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Balance at beginning of period | $					$ 469,524,000	$ 265,476,000	$ 265,476,000
Distributions | $					(7,017,000)		(7,849,000)
Issuance of common units | $					27,898,000		56,469,000
Redemption of common units | $					(41,605,000)		(31,653,000)
Net income | $					6,634,000		18,467,000
Accumulated other comprehensive income allocation | $					(349,000)		175,000
Fair value adjustment | $					(31,664,000)		168,439,000
Balance at end of period | $			$ 423,421,000		$ 423,421,000		$ 469,524,000
SL Green Operating Partnership | Series G Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares		1,902,000
Dividend rate preferred units (as a percent)		4.50%
Liquidation preference of preferred units (in dollars per share)		$ 25
Annual dividends on preferred units (in dollars per share)					$ 1.125
Operating partnership common stock value use for conversion of preferred units (in dollars per share)			$ 88.50		$ 88.50
Number of company common stock issue on redemption of operation partnership common units					1
SL Green Operating Partnership | Series F Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares			60		60
Mandatory liquidation preference (in dollars per share) | $			$ 1,000		$ 1,000
SL Green Operating Partnership | Series K Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares											563,954
Dividend rate preferred units (as a percent)					3.50%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					0.875
Operating partnership common stock value use for conversion of preferred units (in dollars per share)			$ 134.67		$ 134.67
Preferred Units, shares authorized | shares			700,000		700,000
SL Green Operating Partnership | Series L Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares											378,634
Dividend rate preferred units (as a percent)					4.00%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					$ 1
Preferred Units, shares authorized | shares			500,000		500,000
SL Green Operating Partnership | Series M Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares	1,600,000
Dividend rate preferred units (as a percent)					3.75%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					$ 0.9375
Preferred Units, shares authorized | shares			1,600,000		1,600,000
SL Green Operating Partnership | Series N Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares										552,303
Dividend rate preferred units (as a percent)					3.00%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					$ 0.75
Preferred Units, shares authorized | shares			552,303		552,303
SL Green Operating Partnership | Series O Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Dividend rate preferred units (as a percent)					6.25%
Preferred Units, shares authorized | shares			1		1
SL Green Operating Partnership | Series P Preferred Units
Organization
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			200,000		200,000
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares									200,000
Dividend rate preferred units (as a percent)					4.00%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					$ 1
SL Green Operating Partnership | Series Q Preferred Units
Organization
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			268,000		268,000
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares									268,000
Dividend rate preferred units (as a percent)					3.50%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					0.875
Operating partnership common stock value use for conversion of preferred units (in dollars per share)			$ 148.95		$ 148.95
SL Green Operating Partnership | Series R Preferred Units
Organization
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			400,000		400,000
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares								400,000
Dividend rate preferred units (as a percent)					3.50%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					0.875
Operating partnership common stock value use for conversion of preferred units (in dollars per share)			$ 154.89		$ 154.89
SL Green Operating Partnership | Series S Preferred Units
Organization
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			1,077,280		1,077,280
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares								1,077,280
Dividend rate preferred units (as a percent)					4.00%
Liquidation preference of preferred units (in dollars per share)			$ 25		$ 25
Annual dividends on preferred units (in dollars per share)					$ 1
SL Green Operating Partnership | Series A Preferred Units
Organization
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			109,161		109,161
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares								109,161
Dividend rate preferred units (as a percent)					3.50%
Liquidation preference of preferred units (in dollars per share)			$ 1,000		$ 1,000
Annual dividends on preferred units (in dollars per share)					$ 35
SL Green Operating Partnership | Series B Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of preferred units issued (in shares) | shares			0		0

Noncontrolling Interests on t79

Noncontrolling Interests on the Company's Consolidated Financial Statements - Preferred Unit Activity (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	$ (20,650)
SL Green Operating Partnership
Rollforward Analysis of Preferred Unit Activity
Issuance of preferred units	27,898	$ 56,469
Redemption of preferred units	(41,605)	(31,653)
SL Green Operating Partnership | Preferred Units
Rollforward Analysis of Preferred Unit Activity
Balance at beginning of period	71,115	49,550
Issuance of preferred units	211,601	23,565
Redemption of preferred units	(200)	(2,000)
Balance at end of period	$ 282,516	$ 71,115

Stockholders' Equity of the C80

Stockholders' Equity of the Company (Details) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Authorized capital stock (shares)	260,000,000
Authorized shares, par value (in dollars per share)	$ 0.01
Common stock, shares authorized	160,000,000	160,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Excess stock, shares authorized (shares)	75,000,000
Excess stock, par value (in dollars per share)	$ 0.01
Preferred stock, shares authorized (shares)	25,000,000
Preferred stock, par value (in dollars per share)	$ 0.01
Shares issued (shares)	99,659,376
Excess shares issued (shares)	0

Stockholders' Equity of the C81

Stockholders' Equity of the Company (Details 2) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended
	Aug. 31, 2012	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Feb. 28, 2015	Dec. 31, 2014	Jun. 30, 2014
Stockholders' Equity
Proceeds from sale of common stock			$ 124,794,000	$ 42,698,000
Common stock, shares authorized			160,000,000			160,000,000
At-the-Market Equity Offering Programs
Stockholders' Equity
Aggregate value of the shares of common stock to be sold							$ 300,000,000
Contributions - net proceeds from common stock offering (in shares)		895,956
Proceeds from sale of common stock		$ 113,400,000
New At-the-Market Equity offering programs
Stockholders' Equity
Aggregate value of the shares of common stock to be sold		$ 300,000,000
Contributions - net proceeds from common stock offering (in shares)			91,180
Proceeds from sale of common stock			$ 12,000,000
Aggregate value of shares available for issuance			$ 288,000,000
Series I Preferred Stock
Stockholders' Equity
Preferred stock, shares outstanding			9,200,000			9,200,000
Dividend rate preferred units (as a percent)			6.50%
Perpetual Preferred stock, liquidation preference (in dollars per share)			$ 25			$ 25
Perpetual Preferred stock, annual dividends per share (in dollars per share)			$ 1.625
Contributions of net proceeds from sale of preferred stock	$ 221,900,000
Dividend Reinvestment and Stock Purchase Plan (DRIP)
Stockholders' Equity
Contributions - net proceeds from common stock offering (in shares)			775,529
Proceeds from sale of common stock			$ 99,500,000
Common stock, shares authorized					3,500,000

Stockholders' Equity of the C82

Stockholders' Equity of the Company (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic Earnings:
Income attributable to SL Green common stockholders	$ 163,658	$ 64,688	$ 167,829	$ 446,319
Diluted Earnings:
Income attributable to SL Green common stockholders	$ 170,126	$ 67,324	$ 174,463	$ 462,329
Basic Shares:
Weighted average common shares outstanding (shares)	99,621,000	95,734,000	99,205,000	95,437,000
Effect of Dilutive Securities:
Redemption of units to common shares (shares)	3,901,000	3,585,000	3,924,000	3,423,000
Stock-based compensation plans (shares)	407,000	387,000	480,000	462,000
Diluted weighted average common stock outstanding (shares)	103,929,000	99,706,000	103,609,000	99,322,000
Common stock shares excluded from the diluted shares outstanding (shares)	263,236	231,970	233,586	769,790
Common Stock
Effect of Dilutive Securities:
Redemption of units to common shares	$ 6,468	$ 2,636	$ 6,634	$ 16,010

Partners' Capital of the Oper83

Partners' Capital of the Operating Partnership (Details)	Sep. 30, 2015unitshares	Dec. 31, 2014unitshares
Common Stock
Stockholders' Equity
Units outstanding (units)	99,659,000	97,325,000
SL Green Operating Partnership
Stockholders' Equity
Noncontrolling interest in the operating partnership (as a percent)	3.74%	3.92%
Number of units of operating partnership owned by the noncontrolling interest unit holders (units) | unit	3,874,750	3,973,016
SL Green Operating Partnership | Series I Preferred Units
Stockholders' Equity
Units outstanding (units)	9,200,000
SL Green Operating Partnership | Common Stock
Stockholders' Equity
Units outstanding (units)	99,659,376

Partners' Capital of the Oper84

Partners' Capital of the Operating Partnership - EPS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stockholders' Equity
Income attributable to SL Green common stockholders	$ 163,658	$ 64,688	$ 167,829	$ 446,319
Weighted average common shares outstanding (shares)	99,621,000	95,734,000	99,205,000	95,437,000
Common stock shares excluded from the diluted shares outstanding (shares)	263,236	231,970	233,586	769,790
SL Green Operating Partnership
Stockholders' Equity
Income attributable to SL Green common stockholders	$ 170,125	$ 67,324	$ 174,463	$ 462,329
Weighted average common shares outstanding (shares)	103,522,000	99,319,000	103,129,000	98,860,000
Stock-based compensation plans (shares)	407,000	387,000	480,000	462,000
Diluted weighted average common units outstanding (shares)	103,929,000	99,706,000	103,609,000	99,322,000
Common stock shares excluded from the diluted shares outstanding (shares)	263,236	231,970	233,586	769,790

Share-based Compensation - Addi

Share-based Compensation - Additional Information (Details)

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Jan. 31, 2015USD ($)

Aug. 31, 2014shares

Aug. 31, 2011USD ($)

Sep. 30, 2015USD ($)unit / sharesfungible_unitshares

Sep. 30, 2014USD ($)shares

Sep. 30, 2015USD ($)unit / sharesfungible_unit$ / sharesshares

Sep. 30, 2014USD ($)shares

Dec. 31, 2014USD ($)shares

Jun. 30, 2014shares

Dec. 31, 2013shares

Dec. 11, 2013

Dec. 31, 2012shares

Dec. 17, 2012

Dec. 31, 2011shares

Dec. 31, 2010shares

Dec. 31, 2009USD ($)

Jan. 01, 2008shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options

$ 1,500,000

$ 1,700,000

$ 4,900,000

$ 5,200,000

Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Period of commencement of option vesting, from date of grant (in years)

1 year

Exercise price of options granted, low end of the range (in dollars per share) | $ / shares

$ 20.67

Exercise price of options granted, high end of the range (in dollars per share) | $ / shares

$ 137.18

Remaining weighted average contractual life of the options outstanding (in years)

3 years 6 months 24 days

Remaining weighted average contractual life of the options exercisable (in years)

3 years 4 months 11 days

Total unrecognized compensation cost related to unvested stock awards

8,800,000

$ 8,800,000

Weighted average period for recognition of compensation cost related to unvested stock awards (in years)

3 years

Weighted average fair value of options granted during the period

$ 1,112,152

$ 2,841,678

Stock options | Minimum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award expiration period (in years)

5 years

Options vesting period (in years)

1 year

Stock options | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award expiration period (in years)

10 years

Options vesting period (in years)

5 years

Restricted Stock Awards

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation expense

$ 5,663,196

9,658,019

Total unrecognized compensation cost related to unvested stock awards

$ 7,400,000

$ 7,400,000

Weighted average period for recognition of compensation cost related to unvested stock awards (in years)

1 year 8 months 24 days

Annual award vesting rate, low end of range (as a percent)

15.00%

Annual award vesting rate, high end of range (as a percent)

35.00%

Fair value of restricted stock vested during the period

$ 7,400,000

5,500,000

Weighted average fair value of options granted during the period

$ 735,011

$ 1,141,675

Awards granted (in shares) | shares

6,053

9,550

Awards outstanding (in shares) | shares

3,003,315

3,003,315

3,000,979

2,994,197

LTIP units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Weighted average fair value of options granted during the period

$ 25,400,000

$ 33,200,000

Performance Shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Total unrecognized compensation cost related to unvested stock awards

$ 4,600,000

$ 4,600,000

Weighted average period for recognition of compensation cost related to unvested stock awards (in years)

1 year

Share-based Compensation

$ 2,700,000

3,400,000

$ 19,000,000

13,700,000

Third Amendment and Restated 2005 Stock Option and Incentive Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Maximum fungible units that may be granted (in shares) | fungible_unit

17,130,000

17,130,000

Fungible units per share (in fungible units per share) | unit / shares

2.76

2.76

Shares that may be issued if equal to fungible units (shares) (less than) | shares

17,130,000

17,130,000

Fungible units (in shares) | shares

1,700,000

1,700,000

Third Amendment and Restated 2005 Stock Option and Incentive Plan | Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation expense

$ 1,900,000

2,000,000

$ 5,800,000

6,000,000

Stock options, stock appreciation rights and other awards

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Fungible units per share (in fungible units per share) | unit / shares

0.77

0.77

Award expiration period (in years)

5 years

All other awards

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Fungible units per share (in fungible units per share) | unit / shares

1

1

Award expiration period (in years)

10 years

2010 Notional Unit Long-Term Compensation Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation expense

400,000

2,300,000

Capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options

$ 31,700,000

Approximate amount of awards that may be earned by recipients after beginning of the second year if maximum performance achieved

$ 25,000,000

Approximate amount of awards that may be earned by recipients after beginning of the third year if maximum performance achieved

$ 25,000,000

Minimum stock price appreciation to earn maximum amount of awards (as a percent)

50.00%

LTIP units earned (in shares) | shares

327,416

385,583

366,815

Percentage of LTIP Units earned, vested (percent)

25.00%

50.00%

2010 Notional Unit Long-Term Compensation Plan | Minimum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Approximate amount of LTIP units that may be earned by the recipients based on stock price appreciation

$ 15,000,000

2010 Notional Unit Long-Term Compensation Plan | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Approximate amount of LTIP units that may be earned by the recipients based on stock price appreciation

$ 75,000,000

2011 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation expense

$ 600,000

$ 1,700,000

$ 4,500,000

$ 7,800,000

Capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options

26,700,000

Approximate amount of LTIP units that may be earned by the recipients based on stock price appreciation

$ 85,000,000

LTIP units earned (in shares) | shares

280,454

280,454

560,908

Value of LTIP Units that could be earned expressed as percentage of outperformance amount in excess of the 30% benchmark (percent)

10.00%

Duration period return to stockholders exceeds 25% (in years)

3 years

Cumulative return to stockholders (percent)

25.00%

Return to stockholders

$ 85,000,000

Performance period (in years)

3 years

2014 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation expense

1,500,000

4,400,000

Capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options

27,900,000

LTIP units earned (in shares) | shares

610,000

Performance period (in years)

3 years

Award period (in years)

3 years

Percentage of LTIP units that may be earned based on the Company's absolute total return to stockholders

66.67%

Percentage of LTIP units that may be earned based on relative total return to stockholders compared to constituents of the MSCI REIT index

33.33%

Deferred Stock Compensation Plan for Directors

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation expense

$ 100,000

$ 100,000

$ 1,800,000

$ 1,500,000

Maximum percentage of the annual retainer fee, chairman fees and meeting fees that may be deferred by non-employee directors (percent)

100.00%

100.00%

Awards granted (in shares) | shares

8,644

Shares issued (in shares) | shares

5,640

Awards outstanding (in shares) | shares

84,348

84,348

Employee Stock Purchase Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares of common stock available for issuance (shares) | shares

500,000

Duration of each offering period starting the first day of each calendar quarter (in months)

3 months

Purchase price as a percentage of market value of the common stock (percent)

85.00%

85.00%

Shares of common stock issued (shares) | shares

85,317

85,317

Earned anytime after beginning of second year | 2011 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of units vested

33.33%

Vested on August 31, 2014 | 2011 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of units vested

50.00%

Vesting on August 31, 2015 | 2011 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of units vested

50.00%

Earned any time after beginning of third year | 2011 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of units vested

66.67%

Vesting on August 31, 2017 | 2014 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of units vested

50.00%

Vesting on August 31, 2018 | 2014 Outperformance Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Percentage of units vested

50.00%

Share-based Compensation (Detai

Share-based Compensation (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares
Stock options
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Dividend yield (as a percent)	1.74%	1.60%
Expected life of option (in years)	3 years 6 months	3 years 7 months 6 days
Risk-free interest rate (as a percent)	1.17%	1.29%
Expected stock price volatility (as a percent)	34.59%	33.97%
Options Outstanding
Balance at beginning of year (in shares)	1,462,726	1,765,034
Granted (in shares)	40,500	102,050
Exercised (in shares)	(170,035)	(348,156)
Lapsed or cancelled (in shares)	(30,417)	(56,202)
Balance at end of period (in shares)	1,302,774	1,462,726
Options exercisable at end of period (in shares)	594,624	428,951
Weighted average fair value of options granted during the period | $	$ 1,112,152	$ 2,841,678
Weighted Average Exercise Price
Balance at beginning of year (in dollars per share) | $ / shares	$ 87.98	$ 83.24
Granted (in dollars per share) | $ / shares	117.50	119.12
Exercised (in dollars per share) | $ / shares	75.33	72.76
Lapsed or cancelled (in dollars per share) | $ / shares	98.41	90.03
Balance at end of period (in dollars per share) | $ / shares	90.30	87.98
Options exercisable at end of period (in dollars per share) | $ / shares	$ 88.44	$ 90.32
Restricted Stock Awards
Options Outstanding
Weighted average fair value of options granted during the period | $	$ 735,011	$ 1,141,675
Summary of restricted stock
Balance at beginning of year (in shares)	3,000,979	2,994,197
Granted (in shares)	6,053	9,550
Cancelled (in shares)	(3,717)	(2,768)
Balance at end of period (in shares)	3,003,315	3,000,979
Vested during the period (in shares)	87,081	75,043
Compensation expense recorded | $	$ 5,663,196	$ 9,658,019

Accumulated Other Comprehensi87

Accumulated Other Comprehensive Loss of the Company (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	$ (6,980)
Ending Balance	(15,821)
Deferred net losses from terminated hedges	10,300	$ 11,800
SL Green Realty Corp
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	(6,980)
Other comprehensive loss before reclassifications	(17,662)
Amounts reclassified from accumulated other comprehensive income	8,821
Ending Balance	(15,821)
SL Green Realty Corp | Net unrealized (loss) gain on derivative instruments
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	(9,498)
Other comprehensive loss before reclassifications	(14,918)
Amounts reclassified from accumulated other comprehensive income	7,908
Ending Balance	(16,508)
SL Green Realty Corp | Unrealized gain (loss) on marketable securities
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	2,613
Other comprehensive loss before reclassifications	(351)
Amounts reclassified from accumulated other comprehensive income	0
Ending Balance	2,262
SL Green Realty Corp | Joint venture | Net unrealized (loss) gain on derivative instruments
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	(95)
Other comprehensive loss before reclassifications	(2,393)
Amounts reclassified from accumulated other comprehensive income	913
Ending Balance	$ (1,575)

Accumulated Other Comprehensi88

Accumulated Other Comprehensive Loss of the Operating Partnership (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) of the Operating Partnership [Roll Forward]
Beginning Balance	$ (6,980)
Ending Balance	(15,821)
Deferred net losses from terminated hedges	10,300	$ 11,800
SL Green Operating Partnership
Accumulated Other Comprehensive Income (Loss) of the Operating Partnership [Roll Forward]
Beginning Balance	(7,256)
Other comprehensive loss before reclassifications	(18,360)
Amounts reclassified from accumulated other comprehensive income	9,170
Ending Balance	(16,446)
Deferred net losses from terminated hedges	10,700	$ 12,200
Net unrealized (loss) gain on derivative instruments | SL Green Operating Partnership
Accumulated Other Comprehensive Income (Loss) of the Operating Partnership [Roll Forward]
Beginning Balance	(9,845)
Other comprehensive loss before reclassifications	(15,537)
Amounts reclassified from accumulated other comprehensive income	8,221
Ending Balance	(17,161)
Unrealized gain (loss) on marketable securities | SL Green Operating Partnership
Accumulated Other Comprehensive Income (Loss) of the Operating Partnership [Roll Forward]
Beginning Balance	2,689
Other comprehensive loss before reclassifications	(337)
Amounts reclassified from accumulated other comprehensive income	0
Ending Balance	2,352
Joint venture | Net unrealized (loss) gain on derivative instruments | SL Green Operating Partnership
Accumulated Other Comprehensive Income (Loss) of the Operating Partnership [Roll Forward]
Beginning Balance	(100)
Other comprehensive loss before reclassifications	(2,486)
Amounts reclassified from accumulated other comprehensive income	949
Ending Balance	$ (1,637)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value of Financial Instruments
Marketable securities	$ 46,432	$ 39,429
Interest rate cap and swap agreements (included in other assets)	7	2,174
Interest rate cap swap agreements (included in accrued interest payable and other liabilities)	18,019	14,728
Debt and preferred equity investments	1,501,619	1,408,804
Carrying Value
Fair Value of Financial Instruments
Fixed rate debt	7,137,995	6,140,786
Variable rate debt	2,992,508	2,291,943
Total	10,130,503	8,432,729
Fair Value
Fair Value of Financial Instruments
Marketable securities	46,432	39,429
Total	10,626,588	8,881,188
Estimated fair value of debt and preferred equity investments, low end of range	1,700,000	1,500,000
Estimated fair value of debt and preferred equity investments, high end of range	1,900,000	1,800,000
Level 1
Fair Value of Financial Instruments
Interest rate cap and swap agreements (included in other assets)	0	0
Interest rate cap swap agreements (included in accrued interest payable and other liabilities)	0	0
Level 2
Fair Value of Financial Instruments
Interest rate cap and swap agreements (included in other assets)	7	2,174
Interest rate cap swap agreements (included in accrued interest payable and other liabilities)	18,019	14,728
Level 3
Fair Value of Financial Instruments
Marketable securities	0	0
Interest rate cap and swap agreements (included in other assets)	0	0
Interest rate cap swap agreements (included in accrued interest payable and other liabilities)	0	0
Level 3 | Carrying Value
Fair Value of Financial Instruments
Debt and preferred equity investments	1,501,619	1,408,804
Level 3 | Fair Value
Fair Value of Financial Instruments
Fixed rate debt	7,610,830	6,565,236
Variable rate debt	3,015,758	2,315,952
Equity marketable securities
Fair Value of Financial Instruments
Marketable securities	4,115	4,332
Equity marketable securities | Level 1
Fair Value of Financial Instruments
Marketable securities	4,115	4,332
Mortgage-backed securities
Fair Value of Financial Instruments
Marketable securities	42,317	35,097
Mortgage-backed securities | Level 2
Fair Value of Financial Instruments
Marketable securities	$ 42,317	$ 35,097

Financial Instruments_ Deriva90

Financial Instruments: Derivatives and Hedging (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Financial Instruments: Derivatives and Hedging
Fair Value	$ (18,019)		$ (18,019)		$ (14,728)
Fair Value	7		7		$ 2,174
Derivative, Fair Value, Net	(18,012)		(18,012)
Gain (loss) from settlement of hedges included in accumulated other comprehensive loss (less than)	44	$ (7)	43	$ (49)
Fair value of derivatives in a net liability position	18,900		18,900
Aggregate termination value	18,900		18,900
Estimated current balance held in accumulated other comprehensive loss to be reclassified into earnings within the next 12 months			8,700
Share of joint venture of accumulated other comprehensive loss reclassified into equity in net income from unconsolidated joint ventures within the next 12 months			1,000
Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion)	(8,447)	2,052	(18,023)	5,720
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	3,024	1,867	9,170	5,660
Amount of (Loss) or Gain Recognized into Income (Ineffective Portion)	(52)	1	(476)	3
Joint venture
Financial Instruments: Derivatives and Hedging
Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion)	(1,526)	291	(2,486)	4,475
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	287	41	949	1,870
Amount of (Loss) or Gain Recognized into Income (Ineffective Portion)	(21)	0	(21)	0
Interest Rate Cap- Sold Expiring in May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 504,000		$ 504,000
Strike Rate (as a percent)	4.75%		4.75%
Fair Value	$ 0		$ 0
Interest Rate Cap Expiring in May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 504,000		$ 504,000
Strike Rate (as a percent)	4.75%		4.75%
Fair Value	$ 0		$ 0
Interest Rate Cap Expiring In May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 500,000		$ 500,000
Strike Rate (as a percent)	4.75%		4.75%
Fair Value	$ 0		$ 0
Interest Rate Cap- Sold Expiring in May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 500,000		$ 500,000
Strike Rate (as a percent)	4.75%		4.75%
Fair Value	$ 0		$ 0
Interest Rate Cap Expiring In May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 446,000		$ 446,000
Strike Rate (as a percent)	4.75%		4.75%
Fair Value	$ 0		$ 0
Interest Rate Cap Expiring in November, 2015
Financial Instruments: Derivatives and Hedging
Notional Value	$ 263,426		$ 263,426
Strike Rate (as a percent)	6.00%		6.00%
Fair Value	$ 0		$ 0
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 200,000		$ 200,000
Strike Rate (as a percent)	0.9375%		0.9375%
Fair Value	$ (1,087)		$ (1,087)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000		$ 150,000
Strike Rate (as a percent)	0.94%		0.94%
Fair Value	$ (821)		$ (821)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000		$ 150,000
Strike Rate (as a percent)	0.94%		0.94%
Fair Value	$ (821)		$ (821)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 144,000		$ 144,000
Strike Rate (as a percent)	2.236%		2.236%
Fair Value	$ (4,812)		$ (4,812)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 86,400		$ 86,400
Strike Rate (as a percent)	1.9475%		1.9475%
Fair Value	$ (2,345)		$ (2,345)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,000		$ 72,000
Strike Rate (as a percent)	2.31%		2.31%
Fair Value	$ (2,522)		$ (2,522)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,000		$ 72,000
Strike Rate (as a percent)	1.345%		1.345%
Fair Value	$ (1,012)		$ (1,012)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,000		$ 72,000
Strike Rate (as a percent)	2.31%		2.31%
Fair Value	$ (2,522)		$ (2,522)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 57,600		$ 57,600
Strike Rate (as a percent)	1.99%		1.99%
Fair Value	$ (1,616)		$ (1,616)
Interest Rate Swap Expiring in June 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 30,000		$ 30,000
Strike Rate (as a percent)	2.295%		2.295%
Fair Value	$ (415)		$ (415)
Interest Rate Swap Expiring in January 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 14,409		$ 14,409
Strike Rate (as a percent)	0.50%		0.50%
Fair Value	$ (7)		$ (7)
Interest Rate Swap Expiring in February 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 8,018		$ 8,018
Strike Rate (as a percent)	0.852%		0.852%
Fair Value	$ (39)		$ (39)
Interest Rate Cap Expiring in September 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 137,500		$ 137,500
Strike Rate (as a percent)	4.00%		4.00%
Fair Value	$ 7		$ 7
Interest Rate Swap
Financial Instruments: Derivatives and Hedging
Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion)	(6,921)	1,761	(15,537)	1,245
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	2,737	1,826	8,221	3,790
Amount of (Loss) or Gain Recognized into Income (Ineffective Portion)	$ (31)	$ 1	$ (455)	$ 3

Commitments and Contingencies91

Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
Other Commitments [Line Items]
Capital lease obligations	$ 41,171	$ 41,171	$ 20,822
Initial term of non cancellable operating leases, minimum (in years)		1 year
Capital lease
Remaining 2,015	560	$ 560
2,016	2,266	2,266
2,017	2,387	2,387
2,018	2,387	2,387
2,019	2,411	2,411
Thereafter	828,103	828,103
Total minimum lease payments	838,114	838,114
Less amount representing interest	(796,943)	(796,943)
Capital lease obligations	41,171	41,171
Non-cancellable operating leases
Remaining 2,015	7,675	7,675
2,016	30,816	30,816
2,017	31,049	31,049
2,018	31,049	31,049
2,019	31,066	31,066
Thereafter	795,787	795,787
Total minimum lease payments	$ 927,442	927,442
30 East 40th Street
Other Commitments [Line Items]
Land as percentage of fair market value of property under lease	63.60%
Capital lease obligations	$ 20,000	$ 20,000

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)segment	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Segment information
Number of reportable segments (segment) | segment			2
Total revenues	$ 432,066	$ 390,274	$ 1,237,439	$ 1,133,351
(Loss) income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate and purchase price fair value adjustment	20,994	27,556	33,272	130,821
Total assets	19,490,569		$ 19,490,569		$ 17,096,587
Leverage rate assumption (as a percent)			100.00%
Marketing, general and administrative expenses and transaction related costs	23,500	22,600	$ 72,100	69,800
Operating Segments | Real Estate Segment
Segment information
Total revenues	382,738	346,305	1,100,851	995,584
(Loss) income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate and purchase price fair value adjustment	(22,486)	(10,542)	(81,405)	13,148
Total assets	17,966,608		17,966,608		15,671,662
Operating Segments | Debt and Preferred Equity Segment
Segment information
Total revenues	49,328	43,969	136,588	137,767
(Loss) income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate and purchase price fair value adjustment	43,480	$ 38,098	114,677	$ 117,673
Total assets	$ 1,523,961		$ 1,523,961		$ 1,424,925

Segment Information (Details 2)

Segment Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reconciliation of income from continuing operations to net income attributable to SL Green common stockholders
Income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate and purchase price fair value adjustment	$ 20,994	$ 27,556	$ 33,272	$ 130,821
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,281	16,496	16,050	122,580
Depreciable real estate reserves	(19,226)	0	(19,226)	0
Purchase price fair value adjustment	0	(4,000)	0	67,446
Gain on sale of real estate	159,704	0	159,704	0
Income from continuing operations	176,753	40,052	189,800	320,847
Net income from discontinued operations	0	4,035	427	15,449
Gain on sale of discontinued operations	0	29,507	12,983	144,242
Net income	$ 176,753	$ 73,594	$ 203,210	$ 480,538