SL Green Realty (SLG) 10-K 29 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 22, 2016	Jun. 30, 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-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		100,055,035
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 10,300,000,000
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-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		959,844
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Commercial real estate properties, at cost:
Land and land interests	$ 4,779,159	$ 3,844,518
Building and improvements	10,423,739	8,778,593
Building leasehold and improvements	1,431,259	1,418,585
Properties under capital lease	47,445	27,445
Total commercial real estate properties, at cost	16,681,602	14,069,141
Less: accumulated depreciation	(2,060,706)	(1,905,165)
Total commercial real estate properties, net	14,620,896	12,163,976
Assets held for sale	34,981	462,430
Cash and cash equivalents	255,399	281,409
Restricted cash	233,578	149,176
Investments in marketable securities	45,138	39,429
Tenant and other receivables, net of allowance of $17,618 and $18,068 in 2015 and 2014, respectively	63,491	57,369
Related party receivables	10,650	11,735
Deferred rents receivable, net of allowance of $21,730 and $27,411 in 2015 and 2014, respectively	498,776	374,944
Debt and preferred equity investments, net of discounts and deferred origination fees of $18,759 and $19,172 in 2015 and 2014, respectively	1,670,020	1,408,804
Investments in unconsolidated joint ventures	1,203,858	1,172,020
Deferred costs, net	370,435	327,962
Other assets	850,719	647,333
Total assets	19,857,941	17,096,587
Liabilities
Mortgages and other loans payable	6,992,504	5,586,709
Revolving credit facility	994,000	385,000
Term loan and senior unsecured notes	2,319,244	2,107,078
Accrued interest payable and other liabilities	210,883	137,634
Accounts payable and accrued expenses	196,213	173,246
Deferred revenue	399,102	187,148
Capital lease obligations	41,360	20,822
Deferred land leases payable	1,783	1,215
Dividend and distributions payable	79,790	64,393
Security deposits	68,023	66,614
Liabilities related to assets held for sale	29,000	266,873
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities	100,000	100,000
Total liabilities	$ 11,431,902	$ 9,096,732
Commitments and contingencies
Noncontrolling interests in Operating Partnership	$ 424,206	$ 469,524
Preferred units	282,516	71,115
Equity
Common stock, $0.01 par value, 160,000 shares authorized and 100,063 and 97,325 issued and outstanding at December 31, 2015 and 2014, respectively (including 87 shares held in treasury at December 31, 2015)	1,001	974
Additional paid-in-capital	5,439,735	5,113,759
Treasury stock at cost	(10,000)	0
Accumulated other comprehensive loss	(8,749)	(6,980)
Retained earnings	1,643,546	1,607,689
Total SL Green stockholders' equity	7,287,465	6,937,374
Noncontrolling interests in other partnerships	431,852	521,842
Total equity	7,719,317	7,459,216
SL Green stockholders equity:
Total liabilities and equity/capital	19,857,941	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 December 31, 2015 and 2014	221,932	221,932
SL Green Operating Partnership
Commercial real estate properties, at cost:
Land and land interests	4,779,159	3,844,518
Building and improvements	10,423,739	8,778,593
Building leasehold and improvements	1,431,259	1,418,585
Properties under capital lease	47,445	27,445
Total commercial real estate properties, at cost	16,681,602	14,069,141
Less: accumulated depreciation	(2,060,706)	(1,905,165)
Total commercial real estate properties, net	14,620,896	12,163,976
Assets held for sale	34,981	462,430
Cash and cash equivalents	255,399	281,409
Restricted cash	233,578	149,176
Investments in marketable securities	45,138	39,429
Tenant and other receivables, net of allowance of $17,618 and $18,068 in 2015 and 2014, respectively	63,491	57,369
Related party receivables	10,650	11,735
Deferred rents receivable, net of allowance of $21,730 and $27,411 in 2015 and 2014, respectively	498,776	374,944
Debt and preferred equity investments, net of discounts and deferred origination fees of $18,759 and $19,172 in 2015 and 2014, respectively	1,670,020	1,408,804
Investments in unconsolidated joint ventures	1,203,858	1,172,020
Deferred costs, net	370,435	327,962
Other assets	850,719	647,333
Total assets	19,857,941	17,096,587
Liabilities
Mortgages and other loans payable	6,992,504	5,586,709
Revolving credit facility	994,000	385,000
Term loan and senior unsecured notes	2,319,244	2,107,078
Accrued interest payable and other liabilities	210,883	137,634
Accounts payable and accrued expenses	196,213	173,246
Deferred revenue	399,102	187,148
Capital lease obligations	41,360	20,822
Deferred land leases payable	1,783	1,215
Dividend and distributions payable	79,790	64,393
Security deposits	68,023	66,614
Liabilities related to assets held for sale	29,000	266,873
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities	100,000	100,000
Total liabilities	$ 11,431,902	$ 9,096,732
Commitments and contingencies
Preferred units	$ 282,516	$ 71,115
Equity
Accumulated other comprehensive loss	(8,749)	(6,980)
Noncontrolling interests in other partnerships		469,524
SL Green stockholders equity:
Limited partner interests in SLGOP (3,746 and 3,973 limited partner common units outstanding at December 31, 2015 and 2014, respectively)	424,206	469,524
SL Green partners' capital (1,035 and 1,013 general partner common units and 98,941 and 96,312 limited partner common units outstanding at December 31, 2015 2014, respectively)	7,074,282	6,722,422
Total SLGOP partners' capital	7,287,465	6,937,374
Noncontrolling interests in other partnerships	431,852	521,842
Total capital	7,719,317	7,459,216
Total liabilities and equity/capital	19,857,941	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 December 31, 2015 and 2014	$ 221,932	$ 221,932

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Tenant and other receivables, allowance	$ 17,618	$ 18,068
Deferred rents receivable, allowance	21,730	27,411
Debt and preferred equity investments, discount and deferred origination fees	$ 18,759	$ 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	100,063,000	97,325,000
Common stock, shares outstanding	100,063,000	97,325,000
Treasury stock, shares	87,000
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	$ 17,618	$ 18,068
Deferred rents receivable, allowance	21,730	27,411
Debt and preferred equity investments, discount and deferred origination fees	$ 18,759	$ 19,172
Limited partner interests in Operating Partnership, limited partner common units outstanding (shares)	3,746,000	3,973,000
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)	98,941,000	96,312,000
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	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Rental revenue, net	$ 1,245,981	$ 1,121,066	$ 996,782
Escalation and reimbursement	178,512	164,376	155,965
Investment income	181,128	178,815	193,843
Other income	57,208	55,721	24,475
Total revenues	1,662,829	1,519,978	1,371,065
Expenses
Operating expenses, including $20,071 in 2015, $19,308 in 2014, and $19,152 in 2013 of related party expenses	301,624	282,283	276,589
Real estate taxes	232,702	217,843	203,076
Ground rent	32,834	32,307	31,951
Interest expense, net of interest income	323,870	317,400	310,894
Amortization of deferred financing costs	27,348	22,377	15,855
Depreciation and amortization	560,887	371,610	324,461
Transaction related costs	11,430	8,707	3,985
Marketing, general and administrative	94,873	92,488	86,192
Total expenses	1,585,568	1,345,015	1,253,003
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, gain (loss) on sale of marketable securities and loss on early extinguishment of debt	77,261	174,963	118,062
Equity in net income from unconsolidated joint ventures	13,028	26,537	9,921
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Purchase price fair value adjustment	40,078	67,446	(2,305)
Gain on sale of real estate, net	175,974	0	0
Depreciable real estate reserves	(19,226)	0	0
Gain (loss) on sale of investment in marketable securities	0	3,895	(65)
Loss on early extinguishment of debt	(49)	(32,365)	(18,518)
Income from continuing operations	302,910	363,729	110,696
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Net income	317,459	545,863	151,283
Net income attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(10,565)	(18,467)	(3,023)
Net income attributable to noncontrolling interests in other partnerships	(15,843)	(6,590)	(10,629)
Preferred unit distributions	(6,967)	(2,750)	(2,260)
Net income (loss) attributable to SL Green/SLGOP	284,084	518,056	135,371
Preferred stock/unit redemption costs	0	0	(12,160)
Perpetual preferred stock dividends	(14,952)	(14,952)	(21,881)
Amounts attributable to SL Green common stockholders:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	50,502	143,466	60,654
Purchase price fair value adjustment	38,563	65,059	(2,239)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,245	118,891	3,497
Net income from discontinued operations	411	18,400	24,947
Gain on sale of discontinued operations	13,588	157,288	14,471
Gain on sale of real estate	169,322	0	0
Depreciable real estate reserves	(18,499)	0	0
Net income attributable to SL Green common stockholders	$ 269,132	$ 503,104	$ 101,330
Basic earnings per share:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	$ 0.51	$ 1.50	$ 0.66
Purchase price fair value adjustment (usd per share)	0.39	0.68	(0.02)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.64	0.15
Gain on sale of real estate (in dollars per share)	1.71	0	0
Depreciable real estate reserves (in dollars per share)	(0.19)	0	0
Net income attributable to SL Green common stockholders (usd per share)	2.71	5.25	1.10
Diluted earnings per share:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	0.51	1.52	0.66
Purchase price fair value adjustment (usd per share)	0.39	0.65	(0.03)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.63	0.16
Gain on sale of real estate (in dollars per share)	1.70	0	0
Depreciable real estate reserves (in dollars per share)	(0.19)	0	0
Net income attributable to SL Green common stockholders (usd per share)	2.70	5.23	1.10
Dividends per share/unit (usd per share)	$ 2.52	$ 2.10	$ 1.49
Basic weighted average common shares outstanding (in shares)	99,345	95,774	92,269
Diluted weighted average common shares and common share equivalents outstanding (in shares)	103,734	99,696	95,266
SL Green Operating Partnership
Revenues
Rental revenue, net	$ 1,245,981	$ 1,121,066	$ 996,782
Escalation and reimbursement	178,512	164,376	155,965
Investment income	181,128	178,815	193,843
Other income	57,208	55,721	24,475
Total revenues	1,662,829	1,519,978	1,371,065
Expenses
Operating expenses, including $20,071 in 2015, $19,308 in 2014, and $19,152 in 2013 of related party expenses	301,624	282,283	276,589
Real estate taxes	232,702	217,843	203,076
Ground rent	32,834	32,307	31,951
Interest expense, net of interest income	323,870	317,400	310,894
Amortization of deferred financing costs	27,348	22,377	15,855
Depreciation and amortization	560,887	371,610	324,461
Transaction related costs	11,430	8,707	3,985
Marketing, general and administrative	94,873	92,488	86,192
Total expenses	1,585,568	1,345,015	1,253,003
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, gain (loss) on sale of marketable securities and loss on early extinguishment of debt	77,261	174,963	118,062
Equity in net income from unconsolidated joint ventures	13,028	26,537	9,921
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Purchase price fair value adjustment	40,078	67,446	(2,305)
Gain on sale of real estate, net	175,974	0	0
Depreciable real estate reserves	(19,226)	0	0
Gain (loss) on sale of investment in marketable securities	0	3,895	(65)
Loss on early extinguishment of debt	(49)	(32,365)	(18,518)
Income from continuing operations	302,910	363,729	110,696
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Net income	317,459	545,863	151,283
Net income attributable to noncontrolling interests:
Net income attributable to noncontrolling interests in other partnerships	(15,843)	(6,590)	(10,629)
Preferred unit distributions	(6,967)	(2,750)	(2,260)
Net income (loss) attributable to SL Green/SLGOP	294,649	536,523	138,394
Preferred stock/unit redemption costs	0	0	(12,160)
Perpetual preferred unit distributions	(14,952)	(14,952)	(21,881)
Net income attributable to SLGOP common unitholders	279,697	521,571	104,353
Amounts attributable to SL Green common stockholders:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	52,478	148,738	62,470
Purchase price fair value adjustment	40,078	67,446	(2,305)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Gain on sale of real estate	175,974	0	0
Depreciable real estate reserves	$ (19,226)	$ 0	$ 0
Basic earnings per share:
Income from continuing operations before gains on sale and discontinued operations (usd per share)	$ 0.51	$ 1.50	$ 0.66
Purchase price fair value adjustment (usd per share)	0.39	0.68	(0.02)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.64	0.15
Gain on sale of real estate (in dollars per share)	1.71	0	0
Depreciable real estate reserves (in dollars per share)	(0.19)	0	0
Net income attributable to SLGOP common unitholders (usd per share)	2.71	5.25	1.10
Diluted earnings per share:
Income from continuing operations before gains on sale and discontinued operations (usd per share)	0.51	1.52	0.66
Purchase price fair value adjustment (usd per share)	0.39	0.65	(0.03)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.63	0.16
Gain on sale of real estate (in dollars per share)	1.70	0	0
Depreciable real estate reserves (in dollars per share)	(0.19)	0	0
Net income attributable to SLGOP common unitholders (usd per share)	2.70	5.23	1.10
Dividends per share/unit (usd per share)	$ 2.52	$ 2.10	$ 1.49
Basic weighted average common units outstanding (in shares)	103,244	99,288	95,004
Diluted weighted average common units and common unit equivalents outstanding (in shares)	103,734	99,696	95,266

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating expenses, paid to related parties	$ 20,071	$ 19,308	$ 19,152
SL Green Operating Partnership
Operating expenses, paid to related parties	$ 20,071	$ 19,308	$ 19,152

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income	$ 317,459	$ 545,863	$ 151,283
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	(1,229)	10,643	13,490
Change in unrealized (loss) gain on marketable securities	(607)	(2,237)	1,497
Other comprehensive (loss) income	(1,836)	8,406	14,987
Comprehensive income	315,623	554,269	166,270
Net income attributable to noncontrolling interests and preferred units distributions	(33,375)	(27,807)	(15,912)
Other comprehensive income (loss) attributable to noncontrolling interests	67	(175)	(611)
Comprehensive income attributable to SL Green/SLGOP	282,315	526,287	149,747
SL Green Operating Partnership
Net income	317,459	545,863	151,283
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	(1,229)	10,643	13,490
Change in unrealized (loss) gain on marketable securities	(607)	(2,237)	1,497
Other comprehensive (loss) income	(1,836)	8,406	14,987
Comprehensive income	315,623	554,269	166,270
Net income attributable to noncontrolling interests and preferred units distributions	(15,843)	(6,590)	(10,629)
Other comprehensive income (loss) attributable to noncontrolling interests	67	(175)	(611)
Comprehensive income attributable to SL Green/SLGOP	$ 299,847	$ 547,504	$ 155,030

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid- In-Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Noncontrolling Interests	Series C Preferred StockPreferred Stock	Series I Preferred StockPreferred Stock
Beginning Balance at Dec. 31, 2012	$ 6,907,103	$ 913	$ 4,490,084	$ 0	$ (29,587)	$ 1,556,087	$ 487,301	$ 180,340	$ 221,965
Beginning Balance (in shares) at Dec. 31, 2012		91,250
Increase (Decrease) in Stockholders' Equity
Net income	146,000					135,371	10,629
Other comprehensive loss	14,376				14,376
Preferred dividends	(21,881)					(21,881)
DRSPP proceeds	67		67
Conversion of units of the Operating Partnership to common stock (in shares)		239
Conversion of units of the Operating Partnership to common stock	17,287	$ 2	17,285
Redemption of preferred stock	(192,500)					(12,160)		(180,340)
Preferred units issuance costs	(33)								(33)
Reallocation of noncontrolling interest in the Operating Partnership	(45,618)					(45,618)
Deferred compensation plan and stock award, net (in shares)		135
Deferred compensation plan and stock award, net	166	$ 3	4,464	(6,090)		1,789
Amortization of deferred compensation plan	26,329		26,329
Issuance of common stock (in shares)		3,062
Issuance of common stock	290,699	$ 30	290,669
Proceeds from stock options exercised (in shares)		224
Proceeds from stock options exercised	12,904	$ 2	12,902
Sale of treasury stock (in shares)		83
Sale of treasury stock	7,120			6,090		1,030
Contributions to consolidated joint venture interests	8,164						8,164
Cash distributions to noncontrolling interests	(14,623)						(14,623)
Cash distributions declared ($2.52, $2.10, and $1.49 per common share, respectively, none of which represented a return of capital for federal income tax purposes)	(138,684)					(138,684)
Ending Balance at Dec. 31, 2013	7,016,876	$ 950	4,841,800	0	(15,211)	1,475,934	491,471	0	221,932
Ending Balance (in shares) at Dec. 31, 2013		94,993
Increase (Decrease) in Stockholders' Equity
Net income	524,646					518,056	6,590
Other comprehensive loss	8,231				8,231
Preferred dividends	(14,952)					(14,952)
DRSPP proceeds	64		64
Conversion of units of the Operating Partnership to common stock (in shares)		315
Conversion of units of the Operating Partnership to common stock	31,653	$ 3	31,650
Reallocation of noncontrolling interest in the Operating Partnership	(168,439)					(168,439)
Deferred compensation plan and stock award, net (in shares)		15
Deferred compensation plan and stock award, net	(1,514)		(15)			(1,499)
Amortization of deferred compensation plan	29,749		29,749
Issuance of common stock (in shares)		1,654
Issuance of common stock	185,321	$ 17	185,304
Proceeds from stock options exercised (in shares)		348
Proceeds from stock options exercised	25,211	$ 4	25,207
Contributions to consolidated joint venture interests	30,800						30,800
Cash distributions to noncontrolling interests	(7,019)						(7,019)
Cash distributions declared ($2.52, $2.10, and $1.49 per common share, respectively, none of which represented a return of capital for federal income tax purposes)	(201,411)					(201,411)
Ending Balance at Dec. 31, 2014	7,459,216	$ 974	5,113,759	0	(6,980)	1,607,689	521,842	0	221,932
Ending Balance (in shares) at Dec. 31, 2014		97,325
Increase (Decrease) in Stockholders' Equity
Net income	299,927					284,084	15,843
Acquisition of subsidiary interest from noncontrolling interest	(20,650)		(9,566)				(11,084)
Other comprehensive loss	(1,769)				(1,769)
Preferred dividends	(14,952)					(14,952)
DRSPP (in shares)		776
DRSPP proceeds	99,555	$ 8	99,547
Conversion of units of the Operating Partnership to common stock (in shares)		483
Conversion of units of the Operating Partnership to common stock	55,697	$ 5	55,692
Reallocation of noncontrolling interest in the Operating Partnership	20,915					20,915
Reallocation of capital account relating to sale	(10,143)						(10,143)
Deferred compensation plan and stock award, net (in shares)		168
Deferred compensation plan and stock award, net	(2,982)	$ 2	243			(3,227)
Amortization of deferred compensation plan	26,721		26,721
Issuance of common stock (in shares)		1,007
Issuance of common stock	126,989	$ 10	136,979	(10,000)
Proceeds from stock options exercised (in shares)		217
Proceeds from stock options exercised	16,362	$ 2	16,360
Contributions to consolidated joint venture interests	35,178						35,178
Cash distributions to noncontrolling interests	(119,784)						(119,784)
Cash distributions declared ($2.52, $2.10, and $1.49 per common share, respectively, none of which represented a return of capital for federal income tax purposes)	(250,963)					(250,963)
Ending Balance at Dec. 31, 2015	$ 7,719,317	$ 1,001	$ 5,439,735	$ (10,000)	$ (8,749)	$ 1,643,546	$ 431,852	$ 0	$ 221,932
Ending Balance (in shares) at Dec. 31, 2015		99,976

Consolidated Statement of Equi8

Consolidated Statement of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Cash distribution declared, per common share (in dollars per share)	$ 2.52	$ 2.10	$ 1.49

Consolidated Statement of Capit

Consolidated Statement of Capital - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) in Partner's Capital
Acquisition of subsidiary interest from noncontrolling interest	$ (20,650)
Conversion of common units	55,697	$ 31,653	$ 17,287
DRSPP proceeds	99,555	64	67
Redemption of preferred units			(192,500)
Preferred units issuance costs			(33)
Reallocation of capital account relating to sale	(10,143)
Reallocation of noncontrolling interests in the operating partnership	20,915	(168,439)	(45,618)
Deferred compensation plan and stock award, net	(2,982)	(1,514)	166
Amortization of deferred compensation plan	26,721	29,749	26,329
Consolidation of Joint Venture Interest	35,178	30,800	8,164
Contributions-treasury shares			7,120
Cash distributions to noncontrolling interests	$ (119,784)	$ (7,019)	(14,623)
Preferred Units | Series C Preferred Stock
Increase (Decrease) in Partner's Capital
Redemption of preferred units			(180,340)
Preferred Units | Series I Preferred Stock
Increase (Decrease) in Partner's Capital
Preferred units issuance costs			$ (33)
Common Stock
Increase (Decrease) in Partner's Capital
DRSPP (in units)	776
DRSPP proceeds	$ 8
Deferred compensation plan and stock award, net, as adjusted (in units)	168	15	135
Deferred compensation plan and stock award, net	$ 2		$ 3
Contributions - net proceeds from common stock offering (in units)	1,007	1,654	3,062
Contributions-treasury shares (in units)			83
Contributions - proceeds from stock options exercised (in units)	217	348	224
Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Acquisition of subsidiary interest from noncontrolling interest	$ (11,084)
Reallocation of capital account relating to sale	(10,143)
Consolidation of Joint Venture Interest	35,178	$ 30,800	$ 8,164
Cash distributions to noncontrolling interests	(119,784)	(7,019)	(14,623)
SL Green Operating Partnership
Increase (Decrease) in Partner's Capital
Beginning Balance	7,459,216	7,016,876	6,907,103
Net income	299,927	524,646	146,000
Acquisition of subsidiary interest from noncontrolling interest	(20,650)
Other comprehensive income (loss)	(1,769)	8,231	14,376
Preferred distributions	(14,952)	(14,952)	(21,881)
Conversion of common units	55,697	31,653	17,287
DRSPP proceeds	99,555	64	67
Redemption of preferred units			(192,500)
Preferred units issuance costs			(33)
Reallocation of capital account relating to sale	(10,143)
Reallocation of noncontrolling interests in the operating partnership	20,915	(168,439)	(45,618)
Deferred compensation plan and stock award, net	(2,982)	(1,514)	166
Amortization of deferred compensation plan	26,721	29,749	26,329
Consolidation of Joint Venture Interest			8,164
Contribution to consolidated joint venture interests	35,178	30,800
Contributions - net proceeds from common stock offering	126,989	185,321	290,699
Contributions-treasury shares			7,120
Contributions - proceeds from stock options exercised	16,362	25,211	12,904
Cash distributions to noncontrolling interests	(119,784)	(7,019)	(14,623)
Cash distributions declared ($2.52, $2.10, and $1.49 per common unit, respectively, none of which represented a return of capital for federal income tax purposes)	(250,963)	(201,411)	(138,684)
Ending Balance	7,719,317	7,459,216	7,016,876
SL Green Operating Partnership | Preferred Units | Series C Preferred Stock
Increase (Decrease) in Partner's Capital
Beginning Balance	0	0	180,340
Redemption of preferred units			(180,340)
Ending Balance	0	0	0
SL Green Operating Partnership | Preferred Units | Series I Preferred Stock
Increase (Decrease) in Partner's Capital
Beginning Balance	221,932	221,932	221,965
Preferred units issuance costs			(33)
Ending Balance	$ 221,932	221,932	221,932
SL Green Operating Partnership | Common Stock
Increase (Decrease) in Partner's Capital
Issuance of common units (in units)	483
Conversion of common units	$ 55,697
SL Green Operating Partnership | Common Stock | Partners' Interest
Increase (Decrease) in Partner's Capital
Beginning Balance	$ 6,722,422	$ 6,318,684	$ 6,047,084
Beginning Balance (units)	97,325	94,993	91,250
Net income	$ 284,084	$ 518,056	$ 135,371
Acquisition of subsidiary interest from noncontrolling interest	(9,566)
Preferred distributions	$ (14,952)	$ (14,952)	$ (21,881)
Issuance of common units (in units)		315	239
Conversion of common units		$ 31,653	$ 17,287
DRSPP (in units)	776
DRSPP proceeds	$ 99,555	64	67
Redemption of preferred units			(12,160)
Reallocation of noncontrolling interests in the operating partnership	$ 20,915	$ (168,439)	$ (45,618)
Deferred compensation plan and stock award, net, as adjusted (in units)	168	15	135
Deferred compensation plan and stock award, net	$ (2,982)	$ (1,514)	$ 166
Amortization of deferred compensation plan	$ 26,721	$ 29,749	$ 26,329
Contributions - net proceeds from common stock offering (in units)	1,007	1,654	3,062
Contributions - net proceeds from common stock offering	$ 126,989	$ 185,321	$ 290,699
Contributions-treasury shares (in units)			83
Contributions-treasury shares			$ 7,120
Contributions - proceeds from stock options exercised (in units)	217	348	224
Contributions - proceeds from stock options exercised	$ 16,362	$ 25,211	$ 12,904
Cash distributions declared ($2.52, $2.10, and $1.49 per common unit, respectively, none of which represented a return of capital for federal income tax purposes)	(250,963)	(201,411)	(138,684)
Ending Balance	$ 7,074,282	$ 6,722,422	$ 6,318,684
Ending Balance (units)	99,976	97,325	94,993
SL Green Operating Partnership | Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partner's Capital
Beginning Balance	$ (6,980)	$ (15,211)	$ (29,587)
Other comprehensive income (loss)	(1,769)	8,231	14,376
Ending Balance	(8,749)	(6,980)	(15,211)
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Beginning Balance	521,842	491,471	487,301
Net income	15,843	6,590	10,629
Acquisition of subsidiary interest from noncontrolling interest	(11,084)
Reallocation of capital account relating to sale	(10,143)
Consolidation of Joint Venture Interest			8,164
Contribution to consolidated joint venture interests	35,178	30,800
Cash distributions to noncontrolling interests	(119,784)	(7,019)	(14,623)
Ending Balance	$ 431,852	$ 521,842	$ 491,471

Consolidated Statement of Cap10

Consolidated Statement of Capital (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash distribution declared, per common share (in dollars per share)	$ 2.52	$ 2.10	$ 1.49
SL Green Operating Partnership
Cash distribution declared, per common share (in dollars per share)	$ 2.52	$ 2.10	$ 1.49

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income	$ 317,459	$ 545,863	$ 151,283
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	588,238	400,001	357,599
Equity in net income from unconsolidated joint ventures	(13,028)	(26,537)	(9,921)
Distributions of cumulative earnings from unconsolidated joint ventures	40,759	28,859	34,997
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(15,844)	(123,253)	(3,601)
Purchase price fair value adjustment	(40,078)	(71,446)	2,305
Depreciable real estate reserves	19,226	0	2,150
Gain on sale of real estate	(175,974)	0	0
Gain on sale of discontinued operations	(14,122)	(163,059)	(14,900)
Gain on sale of investments in marketable securities	0	(3,895)	0
Loss on early extinguishment of debt	49	32,365	10,963
Deferred rents receivable	(136,924)	(56,362)	(56,739)
Other non-cash adjustments	(20,671)	(28,559)	(37,843)
Changes in operating assets and liabilities:
Restricted cash—operations	11,289	861	2,037
Tenant and other receivables	(6,405)	1,978	(7,570)
Related party receivables	1,278	(3,673)	(917)
Deferred lease costs	(61,005)	(53,333)	(52,228)
Other assets	18,501	9,340	2,904
Accounts payable, accrued expenses and other liabilities and security deposits	8,634	(7,796)	(1,473)
Deferred revenue and land leases payable	5,102	9,027	7,157
Net cash provided by operating activities	526,484	490,381	386,203
Investing Activities
Acquisitions of real estate property	(2,653,311)	(1,039,530)	(594,595)
Additions to land, buildings and improvements	(406,442)	(369,887)	(196,571)
Escrowed cash—capital improvements/acquisition deposits/deferred purchase price	(101,000)	(8,461)	(7,672)
Investments in unconsolidated joint ventures	(161,712)	(382,010)	(150,274)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	98,639	236,181	42,720
Proceeds from disposition of real estate/joint venture interest	1,216,785	820,599	227,615
Proceeds from sale of marketable securities	1,426	8,248	2,370
Purchases of marketable securities	(7,769)	(14,364)	(11,493)
Other investments	(15,806)	(7,448)	(43,163)
Origination of debt and preferred equity investments	(756,939)	(617,090)	(555,137)
Repayments or redemption of debt and preferred equity investments	520,218	576,927	657,765
Net cash used in investing activities	(2,265,911)	(796,835)	(628,435)
Financing Activities
Proceeds from mortgages and other loans payable	1,849,293	2,151,603	1,257,172
Repayments of mortgages and other loans payable	(781,236)	(2,201,999)	(1,085,220)
Proceeds from revolving credit facility and senior unsecured notes	2,515,000	1,908,000	1,164,000
Repayments of revolving credit facility and senior unsecured notes	(1,706,007)	(1,386,588)	(1,020,215)
Payments of debt extinguishment costs	0	(50,150)	0
Proceeds from stock options exercised and DRIP issuance	115,917	25,275	12,971
Proceeds from sale of common stock	124,761	185,321	290,699
Redemption of preferred stock	(200)	(2,000)	(192,533)
Sale or purchase of treasury stock	0	0	7,120
Distributions to noncontrolling interests in other partnerships	(119,784)	(7,019)	(14,623)
Contributions from noncontrolling interests in other partnerships	12,674	30,675	8,164
Distributions to noncontrolling interests in the Operating Partnership	(9,710)	(7,849)	(4,146)
Dividends/Distributions paid on common and preferred stock/units	(257,378)	(206,974)	(148,407)
Other obligations related to mortgage loan participations	25,000	0	0
Deferred loan costs and capitalized lease obligation	(54,913)	(57,124)	(16,042)
Net cash provided by financing activities	1,713,417	381,171	258,940
Net (decrease) increase in cash and cash equivalents	(26,010)	74,717	16,708
Cash and cash equivalents at beginning of year	281,409	206,692	189,984
Cash and cash equivalents at end of period	255,399	281,409	206,692
Supplemental Cash Flow Information [Abstract]
Interest paid	345,110	348,230	325,903
Income taxes paid	3,882	4,056	2,666
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of common stock as deferred compensation	243	1,601	164
Issuance of units in the operating partnership	30,506	56,469	24,750
Redemption of units in the operating partnership	55,697	31,653	17,287
Derivative instruments at fair value	1,816	11,230	636
Exchange of debt investment for equity in joint venture	10,151	0	0
Transfer of restricted cash to operating cash and cash equivalents as a result of sale	21,578	0	0
Acquisition of subsidiary interest from noncontrolling interest	20,630	0	0
Tenant improvements and capital expenditures payable	7,755	9,408	502
Mortgage assigned to joint venture	0	150,000	0
Fair value adjustment to noncontrolling interest in operating partnership	20,915	168,439	45,618
Assumption of mortgage loan	112,795	16,000	84,642
Investment in Joint Venture	0	88,957	0
Capital lease assets	20,000	0	9,992
Reclass of development costs from other assets to real estate	47,519	0	0
Deconsolidation of a subsidiary	27,435	112,095	0
Transfer of assets to assets held for sale	34,981	462,430	0
Transfer of liabilities related to assets held for sale	29,000	266,873	0
Transfer of financing receivable to debt investment	0	19,675	0
Deferred leasing payable	7,832	8,667	5,024
Consolidation of real estate investment	158,566	1,316,591	90,934
Removal of fully depreciated commercial real estate properties	241,910	0	0
Issuance of SLG's common stock to a consolidated joint venture	10,000	0	0
Contribution to consolidated joint venture by noncontrolling interest	22,504	0	0
SL Green Operating Partnership
Operating Activities
Net income	317,459	545,863	151,283
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	588,238	400,001	357,599
Equity in net income from unconsolidated joint ventures	(13,028)	(26,537)	(9,921)
Distributions of cumulative earnings from unconsolidated joint ventures	40,759	28,859	34,997
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(15,844)	(123,253)	(3,601)
Purchase price fair value adjustment	(40,078)	(71,446)	2,305
Depreciable real estate reserves	19,226	0	2,150
Gain on sale of real estate	(175,974)	0	0
Gain on sale of discontinued operations	(14,122)	(163,059)	(14,900)
Gain on sale of investments in marketable securities	0	(3,895)	0
Loss on early extinguishment of debt	49	32,365	10,963
Deferred rents receivable	(136,924)	(56,362)	(56,739)
Other non-cash adjustments	(20,671)	(28,559)	(37,843)
Changes in operating assets and liabilities:
Restricted cash—operations	11,289	861	2,037
Tenant and other receivables	(6,405)	1,978	(7,570)
Related party receivables	1,278	(3,673)	(917)
Deferred lease costs	(61,005)	(53,333)	(52,228)
Other assets	18,501	9,340	2,904
Accounts payable, accrued expenses and other liabilities and security deposits	8,634	(7,796)	(1,473)
Deferred revenue and land leases payable	5,102	9,027	7,157
Net cash provided by operating activities	526,484	490,381	386,203
Investing Activities
Acquisitions of real estate property	(2,653,311)	(1,039,530)	(594,595)
Additions to land, buildings and improvements	(406,442)	(369,887)	(196,571)
Escrowed cash—capital improvements/acquisition deposits/deferred purchase price	(101,000)	(8,461)	(7,672)
Investments in unconsolidated joint ventures	(161,712)	(382,010)	(150,274)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	98,639	236,181	42,720
Proceeds from disposition of real estate/joint venture interest	1,216,785	820,599	227,615
Proceeds from sale of marketable securities	1,426	8,248	2,370
Purchases of marketable securities	(7,769)	(14,364)	(11,493)
Other investments	(15,806)	(7,448)	(43,163)
Origination of debt and preferred equity investments	(756,939)	(617,090)	(555,137)
Repayments or redemption of debt and preferred equity investments	520,218	576,927	657,765
Net cash used in investing activities	(2,265,911)	(796,835)	(628,435)
Financing Activities
Proceeds from mortgages and other loans payable	1,849,293	2,151,603	1,257,172
Repayments of mortgages and other loans payable	(781,236)	(2,201,999)	(1,085,220)
Proceeds from revolving credit facility and senior unsecured notes	2,515,000	1,908,000	1,164,000
Repayments of revolving credit facility and senior unsecured notes	(1,706,007)	(1,386,588)	(1,020,215)
Payments of debt extinguishment costs	0	(50,150)	0
Proceeds from stock options exercised and DRIP issuance	115,917	25,275	12,971
Proceeds from sale of common stock	124,761	185,321	290,699
Redemption of preferred stock	(200)	(2,000)	(192,533)
Sale or purchase of treasury stock	0	0	7,120
Distributions to noncontrolling interests in other partnerships	(119,784)	(7,019)	(14,623)
Contributions from noncontrolling interests in other partnerships	12,674	30,675	8,164
Dividends/Distributions paid on common and preferred stock/units	(267,088)	(214,823)	(152,553)
Other obligations related to mortgage loan participations	25,000	0	0
Deferred loan costs and capitalized lease obligation	(54,913)	(57,124)	(16,042)
Net cash provided by financing activities	1,713,417	381,171	258,940
Net (decrease) increase in cash and cash equivalents	(26,010)	74,717	16,708
Cash and cash equivalents at beginning of year	281,409	206,692	189,984
Cash and cash equivalents at end of period	255,399	281,409	206,692
Supplemental Cash Flow Information [Abstract]
Interest paid	345,110	348,230	325,903
Income taxes paid	3,882	4,056	2,666
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of common stock as deferred compensation	243	1,601	164
Issuance of units in the operating partnership	30,506	56,469	24,750
Redemption of units in the operating partnership	55,697	31,653	17,287
Derivative instruments at fair value	1,816	11,230	636
Exchange of debt investment for equity in joint venture	10,151	0	0
Transfer of restricted cash to operating cash and cash equivalents as a result of sale	21,578	0	0
Acquisition of subsidiary interest from noncontrolling interest	20,630	0	0
Tenant improvements and capital expenditures payable	7,755	9,408	502
Mortgage assigned to joint venture	0	150,000	0
Fair value adjustment to noncontrolling interest in operating partnership	20,915	168,439	45,618
Assumption of mortgage loan	112,795	16,000	84,642
Investment in Joint Venture	0	88,957	0
Capital lease assets	20,000	0	9,992
Reclass of development costs from other assets to real estate	47,519	0	0
Deconsolidation of a subsidiary	27,435	112,095	0
Transfer of assets to assets held for sale	34,981	462,430	0
Transfer of liabilities related to assets held for sale	29,000	266,873	0
Transfer of financing receivable to debt investment	0	19,675	0
Deferred leasing payable	7,832	8,667	5,024
Consolidation of real estate investment	158,566	1,316,591	90,934
Removal of fully depreciated commercial real estate properties	241,910	0	0
Issuance of SLG's common stock to a consolidated joint venture	10,000	0	0
Contribution to consolidated joint venture by noncontrolling interest	22,504	0	0
Common Stock
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units relating to the real estate acquisition	2,228	0	0
Common Stock | SL Green Operating Partnership
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units relating to the real estate acquisition	2,228	0	0
Preferred Units
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units relating to the real estate acquisition	211,601	0	0
Issuance of preferred units (Stonehenge)	0	27,565	0
Preferred Units | SL Green Operating Partnership
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of stock/units relating to the real estate acquisition	211,601	0	0
Issuance of preferred units (Stonehenge)	$ 0	$ 27,565	$ 0

Consolidated Statements of Ca12

Consolidated Statements of Cash Flows (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly distributions declared, per share/unit (usd per share/unit)	$ 0.72	$ 0.60	$ 0.50
SL Green Operating Partnership
Quarterly distributions declared, per share/unit (usd per share/unit)	$ 0.72	$ 0.60	$ 0.50

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 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 December 31, 2015 , noncontrolling investors held, in the aggregate, a 3.61% 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 SL Green Realty Corp. As of December 31, 2015 , we owned the following interests in 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 Property Type Number of Properties Approximate Square Feet (unaudited) Number of Properties Approximate Square Feet (unaudited) Number of Properties Approximate Square Feet (unaudited) Weighted Average Occupancy (1) (unaudited) Commercial: Manhattan Office 27 21,003,606 5 3,024,981 32 24,028,587 94.2 % Retail 9 (2) 408,993 9 347,970 18 756,963 89.1 % Development/Redevelopment 3 42,635 4 1,952,782 7 1,995,417 59.0 % Fee Interest 2 783,530 — — 2 783,530 100.0 % 41 22,238,764 18 5,325,733 59 27,564,497 91.7 % Suburban Office 26 4,235,300 3 705,641 29 4,940,941 79.0 % Retail 1 52,000 — — 1 52,000 100.0 % Development/Redevelopment 1 1,000 1 — 2 1,000 100.0 % 28 4,288,300 4 705,641 32 4,993,941 79.2 % Total commercial properties 69 26,527,064 22 6,031,374 91 32,558,438 89.8 % Residential: Manhattan Residential 4 (2) 762,587 17 2,193,424 21 2,956,011 94.2 % Suburban Residential 1 (3) 66,611 — — 1 66,611 94.4 % Total residential properties 5 829,198 17 2,193,424 22 3,022,622 94.2 % Total portfolio 74 27,356,262 39 8,224,798 113 35,581,060 90.1 % ____________________________________________________________________ (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) As of December 31, 2015 , we owned a building that was comprised of approximately 270,132 square feet (unaudited) of retail space and approximately 222,855 square feet (unaudited) 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. (3) This property was held for sale as of December 31, 2015 . In February 2016, the property was sold. As of December 31, 2015 , we also managed an approximately 336,000 square foot (unaudited) office building owned by a third party and held debt and preferred equity investments with a book value of $1.7 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.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 are $200.7 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 December 31, 2015 and 2014 are $104.5 million and $106.5 million , respectively, related to our consolidated VIEs. As of December 31, 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 requiring 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 Real estate properties are presented at cost less accumulated depreciation and amortization. Costs directly related to the development or redevelopment of properties are capitalized. Ordinary repairs and maintenance are expensed as incurred; major replacements and betterments, which improve or extend the life of the asset, are capitalized and depreciated over their estimated useful lives. A property to be disposed of is reported at the lower of its carrying value or its estimated fair value, less its cost to sell. Once an asset is held for sale, depreciation expense is no longer recorded. The Company adopted ASU 2014-08 effective January 1, 2015. As a result, the Company classified 248-252 Bedford Avenue as held for sale as of December 31, 2015, 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. See Note 4, "Properties Held for Sale and Dispositions." Properties are depreciated using the straight-line method over the estimated useful lives of the assets. The estimated useful lives are as follows: Category Term Building (fee ownership) 40 years Building improvements shorter of remaining life of the building or useful life Building (leasehold interest) lesser of 40 years or remaining term of the lease Property under capital lease remaining lease term Furniture and fixtures four to seven years Tenant improvements shorter of remaining term of the lease or useful life Depreciation expense (including amortization of the capital lease asset) amounted to $523.8 million , $338.8 million and $296.5 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Included in 2015 is $131.8 million of accelerated depreciation expense related to vacating the properties that comprise the One Vanderbilt development site. 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. Except as discussed below, we do not believe that there were any indicators of impairment at any of our consolidated properties at December 31, 2015 . During the three months ended September 30, 2015, we recorded a $19.2 million charge in connection with the sale of two of our properties, which closed in the fourth quarter of 2015. 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." During the fourth quarter of 2015, we entered into an agreement to sell 885 Third Avenue and recorded a $6.6 million charge which was included in gain on sale of real estate, net in the consolidated statement of operations. As of December 31, 2015, 885 Third Avenue was not reclassified as held for sale as a result of not meeting the criteria in ASC 360-10, Property, Plant and Equipment - Impairment and Disposal of Long-Lived Assets. In February 2016, we closed on the sale of this property but do not anticipate meeting the criteria for the full accrual method in ASC 360-20, Property, Plant and Equipment - Real Estate Sales and as a result the property will remain on our consolidated balance sheet until the criteria is met. We incur a variety of costs in the development and leasing of our properties. After determination is made to capitalize a cost, it is allocated to the specific component of a project that is benefited. Determination of when a development project is substantially complete and capitalization must cease involves a degree of judgment. The costs of land and building under development include specifically identifiable costs. The capitalized costs include, but are not limited to, pre-construction costs essential to the development of the property, development costs, construction costs, interest costs, real estate taxes, salaries and related costs and other costs incurred during the period of development. We consider a construction project as substantially completed and held available for occupancy upon the completion of tenant improvements, but no later than one year after major construction activity ceases. We cease capitalization on the portions substantially completed and occupied or held available for occupancy, and capitalize only those costs associated with the portions under construction. Results of operations of properties acquired are included in the consolidated statements of operations from the date of acquisition. We recognize the assets acquired, liabilities assumed (including contingencies) and any noncontrolling interests in an acquired entity at their fair values on the acquisition date. We expense transaction costs related to the acquisition of certain assets as incurred, which are included in transaction related costs on our consolidated statements of operations. When we acquire our partner's equity interest in an existing unconsolidated joint venture and gain control over the investment, we record the consolidated investment at fair value. The difference between the book value of our equity investment on the purchase date and our share of the fair value of the investment's purchase price is recorded as a purchase price fair value adjustment in our consolidated statements of operations. In December 2015, we recognized a purchase price fair value adjustment of $40.1 million in connection with the consolidation of 600 Lexington Avenue. In May 2014, we recognized a purchase price fair value adjustment of $71.4 million in connection with the consolidation of 388-390 Greenwich Street. These acquisitions were previously accounted for as investments in unconsolidated joint ventures. 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. As of December 31, 2015 , the weighted average amortization period for above-market leases, below-market leases, and in-place lease costs is 7.0 years, 20.1 years, and 21.7 years, respectively. We recognized $38.7 million , $23.3 million , and $18.8 million of rental revenue for the years ended December 31, 2015 , 2014 , and 2013 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. The increase in rental revenue for the years ended December 31, 2013 is net of $6.8 million resulting from the write-off of balances associated with a former tenant. Excluding this non-recurring charge, we recognized an increase of $25.6 million in rental revenue for the year ended December 31, 2013 for the amortization of aggregate below-market leases in excess of above-market leases and reductions in lease origination costs.We recognized as a reduction to interest expense the amortization of the above-market rate mortgages assumed of $2.3 million , $5.0 million , and $5.0 million for the years ended December 31, 2015 , 2014 and 2013 , 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 2014 Identified intangible assets (included in other assets): Gross amount $ 939,518 $ 664,297 Accumulated amortization (403,747 ) (383,236 ) Net (1) $ 535,771 $ 281,061 Identified intangible liabilities (included in deferred revenue): Gross amount $ 866,561 $ 655,755 Accumulated amortization (486,928 ) (483,948 ) Net (1) $ 379,633 $ 171,807 ____________________________________________________________________ (1) As of December 31, 2015, $0.2 million and $0.1 million of net intangible assets and net intangible liabilities, respectively, were reclassified to assets held for sale and liabilities related to assets held for sale. The estimated annual amortization of acquired above-market leases, net of acquired (below-market) leases (a component of rental revenue), for each of the five succeeding years is as follows (in thousands): 2016 $ 4,002 2017 2,129 2018 439 2019 (376 ) 2020 (595 ) The estimated annual amortization of all other identifiable assets (a component of depreciation and amortization expense) including tenant improvements for each of the five succeeding years is as follows (in thousands): 2016 $ 9,931 2017 8,507 2018 7,207 2019 6,706 2020 6,453 Cash and Cash Equivalents We consider all highly liquid investments with maturity of three months or less when purchased to be cash equivalents. 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 December 31, 2015 , we did 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 December 31, 2015 and 2014 , we held the following marketable securities (in thousands): December 31, 2015 2014 Equity marketable securities $ 4,704 $ 4,332 Mortgage-backed securities 40,434 35,097 Total marketable securities available-for-sale $ 45,138 $ 39,429 The cost basis of the commercial mortgage-backed securities was $38.7 million and $32.4 million at December 31, 2015 and 2014 , respectively. These securities mature at various times through 2049. During the year ended December 31, 2014, we disposed of marketable securities for aggregate net proceeds of $4.4 million and realized gains of $3.9 million , which is included in gain on sale of investment in marketable securities on the consolidated statements of operations. We did not sell any of our marketable securities during the year ended December 31, 2015. Investments in Unconsolidated Joint Ventures We account for our investments in unconsolidated joint ventures under the equity method of accounting in cases where we exercise significant influence over, but do not control, these entities and are not considered to be the primary beneficiary. We consolidate those joint ventures that we control or which are VIEs and where we are considered to be the primary beneficiary. In all these joint ventures, the rights of the joint venture partner are both protective as well as participating. Unless we are determined to be the primary beneficiary in a VIE, these participating rights preclude us from consolidating these VIE entities. These investments are recorded initially at cost, as investments in unconsolidated joint ventures, and subsequently adjusted for equity in net income (loss) and cash contributions and distributions. Equity in net income (loss) from unconsolidated joint ventures is allocated based on our ownership or economic interest in each joint venture. When a capital event (as defined in each joint venture agreement) such as a refinancing occurs, if return thresholds are met, future equity income will be allocated at our increased economic interest. We recognize incentive income from unconsolidated real estate joint ventures as income to the extent it is earned and not subject to a clawback feature. Distributions we receive from unconsolidated real estate joint ventures in excess of our basis in the investment are recorded as offsets to our investment balance if we remain liable for future obligations of the joint venture or may otherwise be committed to provide future additional financial support. None of the joint venture debt is recourse to us, except for $18.4 million , which we guarantee at one joint venture, and performance guarantees under master leases at two other joint ventures. See Note 6, "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 December 31, 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. Restricted Cash Restricted cash primarily consists of security deposits held on behalf of our tenants, interest reserves, as well as capital improvement and real estate tax escrows required under certain loan agreements. Deferred Lease Costs Deferred lease costs consist of fees and direct costs incurred to initiate and renew operating leases and are amortized on a straight-line basis over the related lease term. Certain of our employees provide leasing services to the wholly-owned properties. For the years ended December 31, 2015 , 2014 and 2013 , $15.4 million , $15.1 million and $12.4 million of their compensation, respectively, was capitalized and is amortized over an estimated average lease term of seven years. Deferred Financing Costs Deferred financing costs represent commitment fees, legal, title and other third party costs associated with obtaining commitments for financing which result in a closing of such financing. These costs are amortized over the terms of the respective agreements. Unamortized deferred financing costs are expensed when the associated debt is refinanced or repaid before maturity. Costs incurred in seeking financing transactions, which do not close, are expensed in the period in which it is determined that the financing will not close. 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 provided that 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. Some 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 an adjustment 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 the loans individually. When a transaction meets the criteria for 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. Allowance for Doubtful Accounts We maintain an allowance for doubtful accounts for estimated losses resulting from the inability of our tenants to make required payments. If the financial condition of a specific tenant were to deteriorate, resulting in an impairment of its ability to make payments, additional allowances may be required. 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 include geographic trends, product diversification, the size of the portfolio and current economic conditions. Based upon these factors, we establish a provision for possible credit loss 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 additional information reflects increased recovery of our investment, we will adjust our reserves accordingly. There were no loan reserves recorded during years ended December 31, 2015 , 2014 , and 2013 . 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. Rent Expense Rent expense is recognized on a straight-line basis over the initial term of the lease. The excess of the rent expense recognized over the amounts contractually due pursuant to the underlying lease is included in the deferred land lease payable on the consolidated balance sheets. Underwriting Commissions and Costs Underwriting commissions and costs incurred in connection with our stock offerings are reflected as a reduction of additional paid-in-capital. Exchangeable Debt Instruments The initial proceeds from exchangeable debt that may be settled in cash, including partial cash settlements, are bifurcated between a liability component and an equity component associated with the embedded conversion option. The objective of the accounting guidance is to require the liability and equity components of exchangeable debt to be separately accounted for in a manner such that the interest expense on the exchangeable debt is not recorded at the stated rate of interest but rather at an effective rate that reflects the issuer's conventional debt borrowing rate at the date of issuance. We calculate the liability component of exchangeable debt based on the present value of the contractual cash flows discounted at our comparable market conventional debt borrowing rate at the date of issuance. The difference between the principal amount and the fair value of the liability component is reported as a discount on the exchangeable debt that is accreted as additional interest expense from the issuance date through the contractual maturity date using the effective interest method. A portion of this additional interest expense may be capitalized to the development and redevelopment balances qualifying for interest capitalization each period. The liability component of the exchangeable debt is reported net of discounts on our consolidated balance sheets. We calculate the equity component of exchangeable debt based on the difference between the initial proceeds received from the issuance of the exchangeable debt and t

Property Acquisitions

Property Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Property Acquisitions	Property Acquisitions 2015 Acquisitions During the year ended December 31, 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): 600 Lexington Avenue (1)(2) 187 Broadway and 5 & 7 Dey Street (1)(3) 11 Madison Avenue (1)(4) 110 Greene Street (1)(5) Upper East Side Residential (1)(6) 1640 Flatbush Avenue (1) Acquisition Date December 2015 August 2015 August 2015 July 2015 June 2015 March 2015 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Property Type Office Residential/Retail Office Office Residential/Retail Retail Purchase Price Allocation: Land $ 97,044 $ 22,101 $ 849,926 $ 89,250 $ 17,500 $ 6,120 Building and building leasehold 180,224 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 277,268 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 $ 277,268 $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Net consideration funded by us at closing, excluding consideration financed by debt $ 79,085 $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Equity and/or debt investment held $ 54,575 $ — $ — $ — $ — $ — Debt assumed $ 112,795 $ — $ — $ — $ — $ — ____________________________________________________________________ (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) In December 2015, we acquired Canada Pension Plan Investment Board's 45% interest in this property, thereby consolidating full ownership of the property. The transaction valued the consolidated interests at $277.3 million . We recognized a purchase price fair value adjustment of $40.1 million upon closing of this transaction. This property, which we initially acquired in May 2010, was previously accounted for as an investment in unconsolidated joint ventures. (3) 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. (4) In August 2015, we acquired this property from a partnership of the Sapir Organization and CIM Group, with whom we have no other relationship. (5) 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. (6) 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 During the year ended December 31, 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 statements of operations for the twelve months ended December 31, 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. 2013 Acquisitions During the year ended December 31, 2013, the properties listed below were acquired from third parties. The following summarizes our allocation of the purchase price of the assets acquired and liabilities assumed upon the closing of these acquisitions (in thousands): 315 West 33rd Street (1) Assemblage of Retail Development Properties on Fifth Avenue (1) 16 Court (2) 248-252 Bedford Avenue (3) Acquisition Date November 2013 November 2013 April 2013 March 2013 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Property Type Residential Development Office Residential Purchase Price Allocation: Land $ 195,834 $ 135,513 $ 19,217 $ 10,865 Building and building leasehold 164,429 10,487 63,210 44,035 Above market lease value 7,084 — 5,122 — Acquired in-place leases 26,125 — 9,422 — Other assets, net of other liabilities 1,142 — 3,380 — Assets acquired 394,614 146,000 100,351 54,900 Mark-to-market assumed debt — — 294 — Below market lease value 7,839 — 3,885 — Liabilities assumed 7,839 — 4,179 — Purchase price $ 386,775 $ 146,000 $ 96,172 $ 54,900 Net consideration funded by us at closing, excluding consideration financed by debt $ 386,775 $ 146,000 $ 4,000 $ 21,782 Equity and/or debt investment held $ — $ — $ 13,835 $ — Debt assumed $ — $ — $ 84,642 $ — ____________________________________________________________________ (1) During the year ended December 31, 2014, we finalized the purchase price allocation based on a third party appraisal and additional facts and circumstances that existed at the acquisition dates. These adjustments did not have a material impact to our consolidated statements of operations for the year ended December 31, 2014. (2) In April 2013, we acquired interests from our joint venture partner, City Investment Fund, or CIF, in 16 Court Street in Brooklyn for $4.0 million . We have consolidated the ownership of the building. The transaction valued the consolidated interest at $96.2 million , inclusive of the $84.6 million mortgage encumbering the property. In April 2014, we repaid the mortgage. We recognized a purchase price fair value adjustment of $(2.3) million upon the closing of this transaction. This property, which we initially acquired in July 2007, was previously accounted for as an investment in unconsolidated joint ventures. (3) In March 2013, we, along with Magnum Real Estate Group, acquired 84 residential units, consisting of 72 apartment units and 12 townhouses, located at 248-252 Bedford Avenue, Williamsburg, Brooklyn for $54.9 million . Simultaneous with the closing on this property, the joint venture closed on a $22.0 million mortgage loan which was later refinanced in June 2014. The property is above a commercial property already owned by us. We hold a 90.0% controlling interest in this joint venture. 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 600 Lexington Avenue and 388-390 Greenwich Street, which were acquired in 2015 and 2014, respectively, 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, are as follows (in thousands): 600 Lexington Avenue 388-390 Greenwich Street Contract purchase price $ 284,000 $ 1,585,000 Net consideration funded by us at closing, excluding consideration financed by debt (79,085 ) (208,614 ) Debt assumed (112,795 ) (1,162,379 ) Fair value of retained equity interest 92,120 214,007 Equity and/or debt investment held (54,575 ) (148,025 ) Other (1) 2,533 5,464 Purchase price fair value adjustment $ 40,078 $ 71,446 ___________________________________________________________________ (1) Includes the acceleration of a deferred leasing commission from the joint venture to the Company. Pro Forma Unaudited The following table summarizes, on an unaudited pro forma basis, the results of operations of 11 Madison Avenue, which are included in the consolidated results of operations for years ended December 31, 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. Year Ended December 31, (in thousands, except per share/unit amounts) 2015 2014 Actual revenues since acquisition $ 29,865 Actual net income since acquisition 159 Pro forma revenues 1,657,937 1,540,525 Pro forma income from continuing operations 102,440 — 376,710 Pro forma basic earnings per share $ 0.76 $ 7.00 Pro forma diluted earnings per share $ 0.75 $ 6.92 Pro forma basic earnings per unit $ 0.76 $ 7.00 Pro forma diluted earnings per unit $ 0.75 $ 6.92 ______________________________________________________________________ (1) The pro forma income from continuing operations for the years ended December 31, 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 year ended December 31, 2014 was adjusted to include the sale of real estate assets for properties that have closed either subsequent to December 31, 2015 or we are currently under contract to sell in connection with 11 Madison Avenue, as if the sales were completed on January 1, 2014. The pro forma net income for the year ended December 31, 2015 excludes these sales.

Properties Held for Sale and Pr

Properties Held for Sale and Property Dispositions	12 Months Ended
	Dec. 31, 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 year ended December 31, 2015 , we entered into an agreement to sell our 90% interest in the unconsolidated joint venture at 248-252 Bedford Avenue in Brooklyn, New York for a total gross asset valuation of $55.0 million . Property Dispositions The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 , and 2013 : Property Disposition Date Property Type Approximate Usable Square Feet Sales Price (1) (in millions) Gain (Loss) on Sale (2) (in millions) 140-150 Grand Street (3) December 2015 Office/Development 215,100 $ 32.0 $ (20.1 ) 570 & 574 Fifth Avenue December 2015 Development 24,327 125.4 24.6 120 West 45th Street September 2015 Office 440,000 365.0 58.6 131-137 Spring Street (4) August 2015 Office 68,342 277.8 101.1 180 Maiden Lane January 2015 Office 1,090,000 470.0 17.0 2 Herald Square November 2014 Land 354,400 365.0 18.8 985-987 Third Avenue July 2014 Development 13,678 68.7 29.8 673 First Avenue May 2014 Office 422,000 145.0 117.6 300 Main Street September 2013 Office 130,000 13.5 (2.2 ) 333 West 34th Street August 2013 Office 345,400 220.3 13.8 44 West 55th Street February 2013 Retail 8,557 6.3 1.1 ____________________________________________________________________ (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 570 & 574 Fifth Avenue, 120 West 45th Street, 131-137 Spring Street, 180 Maiden Lane, 2 Herald Square, 985-987 Third Avenue, 673 First Avenue and 333 West 34th Street are net of $4.0 million , $2.0 million , $4.1 million , $0.8 million , $2.5 million , $1.3 million , $3.4 million and $3.0 million in 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) Gain/(loss) on sale includes a $19.2 million charge that was recorded during the third quarter of 2015. This charge is included in depreciable real estate reserves in the consolidated statement of operations. (4) 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 242-252 Bedford Avenue in Brooklyn, New York as held for sale as of December 31, 2015, 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 years ended December 31, 2015 , 2014 , and 2013 respectively (in thousands): Year Ended December 31, 2015 2014 2013 Revenues Rental revenue $ 236 $ 51,090 $ 94,558 Escalation and reimbursement revenues (127 ) 4,646 14,856 Other income — 23 554 Total revenues 109 55,759 109,968 Operating expenses (631 ) 7,772 20,568 Real estate taxes 250 7,156 16,521 Ground rent — 3,001 7,975 Transaction related costs (49 ) 89 2 Depreciable real estate reserves — — 2,150 Interest expense, net of interest income 109 12,652 19,782 Amortization of deferred financing costs 3 433 840 Depreciation and amortization — 5,581 16,443 Total expenses (318 ) 36,684 84,281 Net income from discontinued operations $ 427 $ 19,075 $ 25,687

Debt and Preferred Equity Inves

Debt and Preferred Equity Investments	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Debt and Preferred Equity Investments	Debt and Preferred Equity Investments During the years ended December 31, 2015 and 2014 , our debt and preferred equity investments, net of discounts and deferred origination fees, increased $781.4 million and $680.1 million , respectively, due to originations, purchases, advances under future funding obligations, discount and fee amortization, and paid-in-kind interest, net of premium amortization. We recorded repayments, participations and sales of $520.2 million and $576.1 million during the years ended December 31, 2015 and 2014 , respectively, which offset the increases in debt and preferred equity investments. Debt Investments As of December 31, 2015 and 2014, we held the following debt investments with an aggregate weighted average current yield of 10.23% at December 31, 2015 (in thousands): Loan Type December 31, 2015 Future Funding Obligations December 31, 2015 Senior Financing December 31, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Fixed Rate Investments: Jr. Mortgage Participation/ Mezzanine Loan (2)(3) $ — $ — $ 23,510 $ 45,611 May 2016 Jr. Mortgage Participation — 133,000 49,000 49,000 June 2016 Mezzanine Loan — 115,000 24,916 24,910 July 2016 Mezzanine Loan — 165,000 72,102 71,656 November 2016 Jr. Mortgage Participation/Mezzanine Loan — 1,109,000 104,661 98,934 March 2017 Mezzanine Loan (3) — — 66,183 65,770 March 2017 Mezzanine Loan (4) — 502,100 41,115 24,608 June 2017 Mezzanine Loan — 539,000 49,691 49,629 July 2018 Mortgage Loan (5) — — 26,262 26,209 February 2019 Mortgage Loan — — 513 637 August 2019 Mezzanine Loan — 15,000 3,500 3,500 September 2021 Mezzanine Loan (6) — 89,880 19,936 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 Jr. Mortgage Participation (9) — — — 70,688 Total fixed rate $ — $ 2,762,980 $ 511,389 $ 607,084 Floating Rate Investments: Mezzanine Loan — 775,000 74,700 73,402 March 2016 Mortgage/Mezzanine Loan 10,156 — 94,901 — April 2016 Mezzanine Loan (10) — 160,000 22,625 22,573 June 2016 Mezzanine Loan 7,942 312,939 66,398 — November 2016 Mezzanine Loan — 360,000 99,530 99,023 November 2016 Mezzanine Loan (11) 11,414 131,939 49,751 42,750 December 2016 Mezzanine Loan 281 39,201 13,731 11,835 December 2016 Mortgage/Mezzanine Loan (12) 57,108 — 134,264 — January 2017 Mezzanine Loan 1,293 118,949 28,551 20,651 January 2017 Mortgage/Mezzanine Loan — — 68,977 — June 2017 Jr. Mortgage Participation/Mezzanine Loan 1,257 118,717 40,346 38,524 July 2017 Loan Type December 31, 2015 Future Funding Obligations December 31, 2015 Senior Financing December 31, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Mortgage/Mezzanine Loan — — 22,877 22,803 July 2017 Mortgage/Mezzanine Loan — — 16,901 16,848 September 2017 Mortgage/Mezzanine Loan 4,500 — 19,282 — October 2017 Mezzanine Loan — 60,000 14,904 14,859 November 2017 Mezzanine Loan — 85,000 29,505 — December 2017 Mezzanine Loan — 65,000 28,563 — December 2017 Mortgage/Mezzanine Loan (13) 795 — 14,942 14,845 December 2017 Jr. Mortgage Participation — 40,000 19,846 — April 2018 Mezzanine Loan — 175,000 34,725 — April 2018 Jr. Mortgage Participation/Mezzanine Loan — 55,000 20,510 20,533 July 2018 Mortgage/Mezzanine Loan (14) 1,500 — 31,210 — August 2018 Mezzanine Loan — 33,000 26,777 December 2018 Mezzanine Loan 6,383 156,383 52,774 — December 2018 Mezzanine Loan 28,801 206,717 49,625 — December 2018 Mortgage/Mezzanine Loan — — 18,395 18,083 February 2019 Mezzanine Loan — 38,000 21,845 21,807 March 2019 Mezzanine Loan (15) — — — 33,726 Mezzanine Loan (15) — — — 37,322 Mortgage/Mezzanine Loan (16) — — — 109,527 Mezzanine Loan (17) — — — 49,614 Total floating rate $ 131,430 $ 2,930,845 $ 1,116,455 $ 668,725 Total $ 131,430 $ 5,693,825 $ 1,627,844 $ 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) These loans were repaid in December 2015. (10) 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. (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) In January 2016, the loans were modified and the mortgage was sold. (15) These loans were repaid in April 2015. (16) This loan was repaid in August 2015. (17) This loan was repaid in November 2015. Preferred Equity Investments As of December 31, 2015 and 2014 , we held the following preferred equity investments with an aggregate weighted average current yield of 7.86% at December 31, 2015 (in thousands): Type December 31, 2015 Future Funding Obligations December 31, 2015 Senior Financing December 31, 2015 Carrying Value (1) December 31, 2014 (1) Initial Mandatory Redemption Preferred equity (2) $ — $ 71,486 $ 9,967 $ 9,954 March 2018 Preferred equity 5,580 60,183 32,209 — November 2018 Preferred equity (3) — — — 123,041 $ 5,580 $ 131,669 $ 42,176 $ 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. The following table is a rollforward of our total loan loss reserves at December 31, 2015 , 2014 and 2013 (in thousands): December 31, 2015 2014 2013 Balance at beginning of year $ — $ 1,000 $ 7,000 Expensed — — — Recoveries — — — Charge-offs and reclassifications — (1,000 ) (6,000 ) Balance at end of period $ — $ — $ 1,000 At December 31, 2015 , 2014 and 2013 , 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 December 31, 2015 and 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 $121.5 million and $133.5 million at December 31, 2015 and 2014 , respectively. No financing receivables were 90 days past due at December 31, 2015 .

Investments in Unconsolidated J

Investments in Unconsolidated Joint Ventures	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 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 $99.6 million and $146.2 million at December 31, 2015 and 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 December 31, 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 (3) Onyx Equities/Credit Suisse 77.78% 77.78% 640,000 April 2007 210,000 11 West 34th Street Private Investor/ Jeff Sutton 30.00% 30.00% 17,150 December 2010 10,800 7 Renaissance (4) Louis Cappelli 50.00% 50.00% 65,641 December 2010 4,000 3 Columbus Circle (5) 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 (6) 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 (7) 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 (8) Private Investors 32.28% 32.28% 16,736 December 2012 75,000 650 Fifth Avenue (9) 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 (10) Various Various Various 2,046,733 February 2015 36,668 131-137 Spring Street (11) 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) In connection with the restructuring of the joint venture and the loan on the property, our ownership increased by 57.52% in October 2015. Our ownership percentage was reduced in the first quarter of 2016 upon completion of the restructuring in the first quarter of 2016. (4) Subsequent to December 31, 2015, we entered into a contract to sell 7 Renaissance for a gross sales price of $20.7 million . The sale is anticipated to close in March 2016, subject to customary closing conditions. (5) 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. (6) 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. (7) 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. (8) 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. (9) 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. (10) 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 . (11) In August 2015, we sold an 80% interest in 131-137 Spring Street. These properties, which were previously wholly-owned, were accounted for in commercial real estate properties on 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 December 31, 2015 and 2014, the carrying value for acquisition, development and construction arrangements were as follows (in thousands): Loan Type December 31, 2015 December 31, 2014 Initial Maturity Date Mezzanine loan and preferred equity $ 99,936 $ 99,629 March 2016 Mezzanine loan (1) 45,942 46,246 February 2022 $ 145,878 $ 145,875 ____________________________________________________________________ (1) We have an option to convert our loan to an equity interest subject to certain conditions. We have determined that our option to convert the loan to equity is not a derivative financial instrument pursuant to GAAP. Sale of Joint Venture Interest or Property The following table summarizes the investments in unconsolidated joint ventures sold during the years ended December 31, 2015 , 2014 , and 2013 : 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 (3) 35.50% September 2015 Ownership Interest 115.0 16.3 180 Broadway (4) 25.50% September 2014 Property 222.5 16.5 747 Madison Avenue (5) 33.33% May 2014 Ownership Interest 160.0 — West Coast Office portfolio (6) 42.02% March 2014 Ownership Interest 756.0 85.6 21-25 West 34th Street (7) 49.90% January 2014 Ownership Interest 114.9 20.9 27-29 West 34th Street (8) 50.00% December 2013 Ownership Interest 70.1 7.6 West Coast Office Portfolio (6) 42.04% Various dates in 2013 Property 224.3 2.1 ___________________________________________________________________ (1) Represents implied gross valuation for the joint venture or sales price of the property. (2) Represents the Company's share of the gain or loss. (3) The gain on sale for 315 West 36th Street is net of $1.2 million 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. (4) In connection with the sale of the property, we also recognized a promote of $3.3 million . (5) We sold our ownership interest in the joint venture, which owns 100% interest as tenant-in-common in 30 East 65th Street Corporation and the related proprietary lease of five cooperative apartment units in the property. We also recognized a promote of $10.3 million and originated a $30.0 million preferred equity investment. Given our continuing involvement as a preferred equity holder, we deferred the gain on sale of $13.1 million as we did not meet the requirements of a sale under the full accrual method. We, along with our joint venture partners, retained one apartment unit at this property. (6) During the year ended December 31, 2013, the joint venture sold three properties, the proceeds of which were used primarily to repay a portion of the debt. Also during the year ended December 31, 2013, we acquired in aggregate 14.39% ownership interest of two of our joint venture partners. As a result, we had a 42.04% effective ownership interest ( 43.74% effective economic interest) in the West Coast portfolio as of December 31, 2013. During the year ended December 31, 2014, we sold our ownership interest in the joint venture. (7) We sold our ownership interest in the joint venture. We, along with our joint venture partner, retained approximately 91,300 square feet (unaudited) of development rights at the property. (8) We sold our ownership interest in the joint venture. The gain on the sale is net of a $1.5 million employee compensation award, accrued in connection with the realization of this investment gain as a bonus to certain employees that were instrumental in realizing the gain on this sale. Simultaneously, we, along with Sutton, also formed a new joint venture and retained the air rights at this property. In December 2013, the preferred equity interest held by the joint venture which holds Herald Center was redeemed. This preferred equity interest bore interest at a rate of 8.75% per annum through the redemption date. 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 December 31, 2015 and 2014 , respectively, are as follows (amounts in thousands): Property Maturity Date Interest Rate (1) December 31, 2015 December 31, 2014 Fixed Rate Debt: 280 Park Avenue June 2016 6.57 % $ 692,963 $ 700,171 7 Renaissance December 2016 10.00 % 2,927 2,147 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 % 170,000 170,000 717 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 % 325,704 314,381 3 Columbus Circle (4) March 2025 3.45 % 350,000 — Stonehenge Portfolio (5) Various 4.18 % 430,627 — 315 West 36th Street (6) — 25,000 11 West 34th Street — 16,905 Total fixed rate debt $ 2,808,881 $ 2,065,264 Floating Rate Debt: 1552 Broadway (7) April 2016 4.35 % 190,409 184,210 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 4.26 % 40,000 40,000 10 East 53rd Street February 2017 2.70 % 125,000 125,000 724 Fifth Avenue April 2017 2.61 % 275,000 275,000 33 Beekman (9) August 2017 2.94 % 73,518 52,283 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 11 West 34th Street (11) January 2021 4.57 % 23,000 — 100 Park Avenue February 2021 1.95 % 360,000 360,000 131-137 Spring Street August 2020 1.76 % 141,000 — 21 East 66th Street June 2033 2.97 % 1,805 1,883 3 Columbus Circle (4) — 230,974 The Meadows (12) — 67,350 600 Lexington Avenue (13) — 116,740 Total floating rate debt $ 1,500,232 $ 1,713,440 Total joint venture mortgages and other loans payable $ 4,309,113 $ 3,778,704 ____________________________________________________________________ (1) Effective weighted average interest rate for the year ended December 31, 2015 , taking into account interest rate hedges in effect during the period. (2) As of December 31, 2015, we were in the process of restructuring the joint venture, which would reduce our ownership interest, and the loan on the Property. Subsequent to December 31, 2015, we along with our joint venture partners closed on the restructuring and refinancing. We hold an 11.67% non-controlling interest in the joint venture and the property secures a two year $100.0 million floating rate loan, of which $75.0 million is currently outstanding. (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 $13.3 million , $55.5 million , $35.0 million , $7.3 million , $141.5 million , and $177.9 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 December 31, 2015 , $0.6 million of the mortgage loan and $0.5 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 December 31, 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. The sale of this property is currently under contract, and the sale is expected to be completed in the first half of 2016. (10) This loan has a committed amount of $190.0 million , of which $40.0 million was unfunded as of December 31, 2015 . (11) In December 2015, the joint venture refinanced the previous mortgage. (12) In August 2015, these properties were sold and the debt was repaid. (13) In December 2015, we acquired our joint venture partner's interest in 600 Lexington Avenue thereby assuming full ownership, and accounting for the property on a consolidated basis. 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 $6.9 million , $16.9 million and $4.7 million from these services for the years ended December 31, 2015 , 2014 , and 2013 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 December 31, 2015 and 2014, are as follows (in thousands): December 31, 2015 December 31, 2014 Assets Commercial real estate property, net $ 6,122,468 $ 5,275,632 Other assets 904,283 810,567 Total assets $ 7,026,751 $ 6,086,199 Liabilities and members' equity Mortgages and other loans payable $ 4,309,113 $ 3,778,704 Other liabilities 523,160 485,572 Members' equity 2,194,478 1,821,923 Total liabilities and members' equity $ 7,026,751 $ 6,086,199 Company's investments in unconsolidated joint ventures $ 1,203,858 $ 1,172,020 The combined statements of operations for the unconsolidated joint ventures, from acquisition date through the years ended December 31, 2015 , 2014 , and 2013 are as follows (in thousands): Year Ended December 31, 2015 2014 2013 Total revenues $ 576,845 $ 522,132 $ 628,649 Operating expenses 106,613 82,436 114,633 Ground rent 14,083 9,898 2,863 Real estate taxes 89,734 64,217 71,755 Interest expense, net of interest income 199,126 178,743 225,765 Amortization of deferred financing costs 13,394 12,395 17,092 Transaction related costs 615 535 808 Depreciation and amortization 149,023 137,793 192,504 Total expenses 572,588 486,017 625,420 Loss on early extinguishment of debt (1,089 ) (6,743 ) — Net income before gain on sale $ 3,168 $ 29,372 $ 3,229 Company's equity in net income from unconsolidated joint ventures $ 13,028 $ 26,537 $ 9,921

Deferred Costs

Deferred Costs	12 Months Ended
	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs	Deferred Costs Deferred costs at December 31, 2015 and 2014 consisted of the following (in thousands): December 31, 2015 2014 Deferred leasing $ 415,406 $ 385,555 Deferred financing 241,775 193,776 657,181 579,331 Less accumulated amortization (286,746 ) (251,369 ) Deferred costs, net $ 370,435 $ 327,962

Mortgages and Other Loans Payab

Mortgages and Other Loans Payable	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 , respectively, were as follows (amounts in thousands): Property Maturity Date Interest Rate (1) December 31, 2015 December 31, 2014 Fixed Rate Debt: 500 West Putnam Avenue (2) January 2016 5.52 % 22,376 22,968 Landmark Square December 2016 4.00 % 79,562 81,269 485 Lexington Avenue February 2017 5.61 % 450,000 450,000 762 Madison Avenue (3) February 2017 3.84 % 7,872 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 % 542,817 565,742 100 Church Street July 2022 4.68 % 225,099 228,612 919 Third Avenue (5) June 2023 5.12 % 500,000 500,000 400 East 57th Street February 2024 4.13 % 67,644 68,896 400 East 58th Street February 2024 4.13 % 28,990 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 $ 5,816,010 $ 4,736,709 Floating Rate Debt: Master Repurchase Agreement June 2016 3.36 % 253,424 100,000 FHLB Facility (9) Various Various 45,750 — 600 Lexington Avenue October 2017 2.30 % 112,795 — 187 Broadway & 5-7 Dey Street October 2017 2.85 % 40,000 — 388-390 Greenwich Street (4) June 2018 1.94 % 446,000 446,000 1080 Amsterdam November 2018 3.96 % 3,525 — 248-252 Bedford Avenue (10) June 2019 1.69 % 29,000 29,000 220 East 42nd Street October 2020 1.80 % 275,000 275,000 180 Maiden Lane (11) — 253,942 Total floating rate debt $ 1,205,494 $ 1,103,942 Total fixed rate and floating rate debt $ 7,021,504 $ 5,840,651 Mortgages reclassed to liabilities related to assets held for sale (29,000 ) (253,942 ) Total mortgages and other loans payable $ 6,992,504 $ 5,586,709 ____________________________________________________________________ (1) Effective weighted average interest rate for the year ended December 31, 2015 , taking into account interest rate hedges in effect during the period. (2) In January 2016, the mortgage was repaid. (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 in May 2014, 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 consolidated 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 , 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, the mortgage was repaid. (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) The FHLB Facility is comprised of four distinct advances of $1.0 million , $15.8 million , $5.0 million , and $24.0 million that mature in April 2016, April 2016, June 2016 and December 2016, respectively. The weighted average interest rates on these advances range from 0.50% to 0.58% . (10) This property was held for sale at December 31, 2015 and the related mortgage is included in liabilities related to assets held for sale. In February 2016, the property was sold and the debt was repaid. (11) 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 year ended December 31, 2015 , the Company’s wholly-owned subsidiary, Belmont Insurance Company, or Belmont, a New York licensed captive insurance company, became a member of the Federal Home Loan Bank of New York, or FHLBNY. As a member, Belmont may borrow funds from the FHLBNY in the form of secured advances. As of December 31, 2015 , we had $45.8 million in outstanding secured advances with a weighted average borrowing rate of 0.55% . On January 12, 2016, the Federal Housing Finance Agency, or FHFA, adopted a final regulation on Federal Home Loan Bank, or FHLB, membership. The rule excludes captive insurance entities from FHLB membership on a going-forward basis and provides termination rules for current captive insurance members. Unless the final rule is modified, Belmont's membership will terminate on February 19, 2017. 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 2015, we entered into an amendment to the MRA to extend the maturity to June 29, 2016. Further, as of December 6, 2015 we are now 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 December 31, 2015 and 2014 , the gross book value of the properties and debt and preferred equity investments collateralizing the mortgages and other loans payable was approximately $10.8 billion and $8.2 billion , respectively.

Corporate Indebtedness

Corporate Indebtedness	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Corporate Indebtedness	Corporate Indebtedness 2012 Credit Facility In July 2015, we entered into the third amendment to the credit facility that was originally entered into by the Company in November 2012, referred to as 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 December 31, 2015 , the 2012 credit facility, as amended, consisted of a $1.6 billion revolving credit facility and a $933.0 million term loan. 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 December 31, 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 December 31, 2015 , the applicable spread was 125 basis points for revolving credit facility and 140 basis points for the term loan facility. At December 31, 2015 , the effective interest rate was 1.45% for the revolving credit facility and 1.67% 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 December 31, 2015 , the facility fee was 25 basis points. As of December 31, 2015 , we had $73.1 million of outstanding letters of credit, $994.0 million drawn under the revolving credit facility and $933.0 million outstanding under the term loan facility, with total undrawn capacity of $532.9 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 December 31, 2015 and 2014 , respectively, by scheduled maturity date (dollars in thousands): Issuance December 31, 2015 Unpaid Principal Balance December 31, 2015 Accreted Balance December 31, 2014 Accreted Balance Coupon Rate (1) Effective Rate Term (in Years) Maturity Date March 31, 2006 (2)(3) $ 255,308 $ 255,296 $ 255,250 6.00 % 6.00 % 10 March 31, 2016 October 12, 2010 (4) 345,000 321,130 309,069 3.00 % 3.00 % 7 October 15, 2017 August 5, 2011 (5) 250,000 249,810 249,744 5.00 % 5.00 % 7 August 15, 2018 March 16, 2010 (5) 250,000 250,000 250,000 7.75 % 7.75 % 10 March 15, 2020 November 15, 2012 (5) 200,000 200,000 200,000 4.50 % 4.50 % 10 December 1, 2022 December 17, 2015 (5) 100,000 100,000 — 4.27 % 4.27 % 10 December 17, 2025 March 26, 2007 (6) 10,008 10,008 10,008 3.00 % 3.00 % 20 March 30, 2027 June 27, 2005 (2)(7) — — 7 $ 1,410,316 $ 1,386,244 $ 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) The notes will be repaid at maturity. (4) 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 12.3416 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, 2016 and will remain exchangeable through March 31, 2016. The notes are guaranteed by ROP. On the issuance date, $78.3 million of the debt balance was recorded in equity. As of December 31, 2015 , $23.9 million remained to be amortized into the debt balance. (5) Issued by the Company, the Operating Partnership and ROP, as co-obligors. (6) 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. (7) 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 December 31, 2015 and 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 December 31, 2015 , including as-of-right extension options and put options, were as follows (in thousands): Scheduled Amortization Principal Revolving Credit Facility Unsecured Term Loan Trust Preferred Securities Senior Unsecured Notes Total Joint Venture Debt 2016 $ 51,018 $ 399,486 $ — $ — $ — $ 255,308 $ 705,812 $ 529,646 2017 63,829 871,548 — — — 355,008 1,290,385 615,085 2018 64,462 19,525 — — — 250,000 333,987 2,195 2019 70,409 28,317 — 933,000 — — 1,031,726 104,687 2020 52,799 679,531 994,000 — — 250,000 1,976,330 30,298 Thereafter 147,604 4,572,974 — — 100,000 300,000 5,120,578 451,544 $ 450,121 $ 6,571,381 $ 994,000 $ 933,000 $ 100,000 $ 1,410,316 $ 10,458,818 $ 1,733,455 Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Year Ended December 31, 2015 2014 2013 Interest expense $ 326,818 $ 319,898 $ 312,897 Interest income (2,948 ) (2,498 ) (2,003 ) Interest expense, net $ 323,870 $ 317,400 $ 310,894 Interest capitalized $ 31,108 $ 22,750 $ 11,475

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 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 $3.8 million , $3.8 million , and $3.5 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. We also recorded expenses, inclusive of capitalized expenses, of $21.3 million , $21.5 million , and $23.4 million the years ended December 31, 2015 , 2014 and 2013 , 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 this entity of $0.5 million , $0.4 million and $0.4 million for the years ended December 31, 2015 , 2014 , and 2013 respectively. Other Amounts due from related parties at December 31, 2015 and 2014 consisted of the following (in thousands): December 31, 2015 2014 Due from joint ventures $ 1,334 $ 1,254 Other 9,316 10,481 Related party receivables $ 10,650 $ 11,735

Noncontrolling Interests on the

Noncontrolling Interests on the Company's Consolidated Financial Statements	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014, the noncontrolling interest unit holders owned 3.61% , or 3,745,766 units, and 3.92% , or 3,973,016 units, of the Operating Partnership, respectively. At December 31, 2015 , 3,745,766 shares of SL Green's common stock were reserved for issuance upon the 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 2014 Balance at beginning of period $ 469,524 $ 265,476 Distributions (9,710 ) (7,849 ) Issuance of common units 30,506 56,469 Redemption of common units (55,697 ) (31,653 ) Net income 10,565 18,467 Accumulated other comprehensive income allocation (67 ) 175 Fair value adjustment (20,915 ) 168,439 Balance at end of period $ 424,206 $ 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 December 31, 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 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	12 Months Ended
	Dec. 31, 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 December 31, 2015 , 99,975,238 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In July 2011, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $250.0 million of SL Green's common stock. During the year ended December 31, 2014 , we sold 25,659 shares of our common stock out of the remaining balance of the ATM Program for aggregate net proceeds of $2.8 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 25,659 units of limited partnership interest of the Operating Partnership. 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 year ended December 31, 2014 , we sold 1,626,999 shares of our common stock for aggregate net proceeds of $182.9 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 1,626,999 units of limited partnership interest of the Operating Partnership. 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 year ended December 31, 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 December 31, 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. The following table summarizes SL Green common stock issued, and proceeds received from dividend reinvestments and/or stock purchases under the DRSPP for the year ended December 31, 2015, 2014, and 2013, respectively (in thousands): Year Ended December 31, 2015 2014 2013 Common Stock Shares Issued 775,760 608 761 Dividend reinvestments/stock purchases under the DRSPP $ 99,555 $ 64 $ 67 Earnings per Share SL Green's earnings per share for the years ended December 31, 2015 , 2014 , and 2013 are computed as follows (in thousands): Year Ended December 31, Numerator 2015 2014 2013 Basic Earnings: Income attributable to SL Green common stockholders $ 269,132 $ 503,104 $ 101,330 Effect of Dilutive Securities: Redemption of units to common shares 10,565 18,467 3,023 Diluted Earnings: Income attributable to SL Green common stockholders $ 279,697 $ 521,571 $ 104,353 Year Ended December 31, Denominator 2015 2014 2013 Basic Shares: Weighted average common stock outstanding 99,345 95,774 92,269 Effect of Dilutive Securities: Redemption of units to common shares 3,899 3,514 2,735 Stock-based compensation plans 490 408 262 Diluted weighted average common stock outstanding 103,734 99,696 95,266 SL Green has excluded 263,991 , 737,361 , and 964,789 common stock equivalents from the diluted shares outstanding for the years ended December 31, 2015 , 2014 , and 2013 respectively, as they were anti-dilutive.

Partners' Capital of the Operat

Partners' Capital of the Operating Partnership	12 Months Ended
	Dec. 31, 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 December 31, 2015 , 99,975,238 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In July 2011, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $250.0 million of SL Green's common stock. During the year ended December 31, 2014 , we sold 25,659 shares of our common stock out of the remaining balance of the ATM Program for aggregate net proceeds of $2.8 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 25,659 units of limited partnership interest of the Operating Partnership. 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 year ended December 31, 2014 , we sold 1,626,999 shares of our common stock for aggregate net proceeds of $182.9 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 1,626,999 units of limited partnership interest of the Operating Partnership. 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 year ended December 31, 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 December 31, 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. The following table summarizes SL Green common stock issued, and proceeds received from dividend reinvestments and/or stock purchases under the DRSPP for the year ended December 31, 2015, 2014, and 2013, respectively (in thousands): Year Ended December 31, 2015 2014 2013 Common Stock Shares Issued 775,760 608 761 Dividend reinvestments/stock purchases under the DRSPP $ 99,555 $ 64 $ 67 Earnings per Share SL Green's earnings per share for the years ended December 31, 2015 , 2014 , and 2013 are computed as follows (in thousands): Year Ended December 31, Numerator 2015 2014 2013 Basic Earnings: Income attributable to SL Green common stockholders $ 269,132 $ 503,104 $ 101,330 Effect of Dilutive Securities: Redemption of units to common shares 10,565 18,467 3,023 Diluted Earnings: Income attributable to SL Green common stockholders $ 279,697 $ 521,571 $ 104,353 Year Ended December 31, Denominator 2015 2014 2013 Basic Shares: Weighted average common stock outstanding 99,345 95,774 92,269 Effect of Dilutive Securities: Redemption of units to common shares 3,899 3,514 2,735 Stock-based compensation plans 490 408 262 Diluted weighted average common stock outstanding 103,734 99,696 95,266 SL Green has excluded 263,991 , 737,361 , and 964,789 common stock equivalents from the diluted shares outstanding for the years ended December 31, 2015 , 2014 , and 2013 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 December 31, 2015 owned 99,975,238 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 December 31, 2015 , limited partners other than SL Green owned 3.61% , or 3,745,766 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 years ended December 31, 2015 , 2014 , and 2013 respectively are computed as follows (in thousands): Year Ended December 31, Numerator 2015 2014 2013 Basic and Diluted Earnings: Income attributable to SLGOP common unitholders $ 279,697 $ 521,571 $ 104,353 Year Ended December 31, Denominator 2015 2014 2013 Basic units: Weighted average common units outstanding 103,244 99,288 95,004 Effect of Dilutive Securities: Stock-based compensation plans 490 408 262 Diluted weighted average common units outstanding 103,734 99,696 95,266 The Operating Partnership has excluded 263,991 , 737,361 and 964,789 common unit equivalents from the diluted units outstanding for the years ended December 31, 2015 , 2014 , and 2013 respectively, as they were anti-dilutive.

Share-based Compensation

Share-based Compensation	12 Months Ended
	Dec. 31, 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 December 31, 2015 , 1.1 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 years ended December 31, 2015 , 2014 , and 2013 . 2015 2014 2013 Dividend yield 1.97 % 1.60 % 1.92 % Expected life of option 3.6 years 3.6 years 4.1 years Risk-free interest rate 1.43 % 1.29 % 0.96 % Expected stock price volatility 32.34 % 33.97 % 36.12 % A summary of the status of the Company's stock options as of December 31, 2015 , 2014 , and 2013 and changes during the years ended December 31, 2015 , 2014 , and 2013 are as follows: 2015 2014 2013 Options Outstanding Weighted Average Exercise Price Options Outstanding Weighted Average Exercise Price Options Weighted Balance at beginning of year $ 1,462,726 $ 87.98 $ 1,765,034 $ 83.24 $ 1,201,000 $ 75.05 Granted 389,836 112.54 102,050 119.12 828,100 87.23 Exercised (217,438 ) 74.69 (348,156 ) 72.76 (223,531 ) 53.93 Lapsed or cancelled (40,117 ) 98.61 (56,202 ) 90.03 (40,535 ) 83.94 Balance at end of year $ 1,595,007 $ 95.52 $ 1,462,726 $ 87.98 $ 1,765,034 $ 83.24 Options exercisable at end of year 589,055 $ 89.85 428,951 $ 90.32 $ 461,458 $ 89.38 Weighted average fair value of options granted during the year $ 9,522,613 $ 2,841,678 $ 18,041,576 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 3.75 years and the remaining average contractual life of the options exercisable was 3.47 years. During the years ended December 31, 2015 , 2014 , and 2013 respectively, we recognized $8.0 million, $8.1 million and $6.5 million of compensation expense, respectively, for these options. As of December 31, 2015 , there was $14.9 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 December 31, 2015 , 2014 , and 2013 and charges during the years ended December 31, 2015 , 2014 , and 2013 are as follows: 2015 2014 2013 Balance at beginning of year 3,000,979 2,994,197 2,804,901 Granted 143,053 9,550 192,563 Cancelled (6,151 ) (2,768 ) (3,267 ) Balance at end of year 3,137,881 3,000,979 2,994,197 Vested during the year 87,081 75,043 21,074 Compensation expense recorded $ 7,540,747 $ 9,658,019 $ 6,713,155 Weighted average fair value of restricted stock granted during the year $ 16,061,201 $ 1,141,675 $ 17,386,949 The fair value of restricted stock that vested during the years ended December 31, 2015, 2014, and 2013 was $7.4 million and $5.5 million , and $1.6 million , respectively. As of December 31, 2015 , there was $21 million of total unrecognized compensation cost related to unvested restricted stock, which is expected to be recognized over a weighted average period of 2.7 years . For the years ended December 31, 2015, 2014, and 2013 , $6.5 million , $6.8 million and $4.5 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 December 31, 2015 and 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 December 31, 2015 , there was $2.0 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 1.4 years . During the years ended December 31, 2015, 2014, and 2013 , we recorded compensation expense related to bonus, time-based and performance based awards of $30.2 million , $ 31.4 million and $ 27.3 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, 385,583 LTIP Units, 327,416 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 $ 2.7 million and $4.5 million during the years ended December 31, 2014 and 2013, respectively, 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 $4.5 million , $8.6 million and $8.0 million during the years ended December 31, 2015, 2014, and 2013 , 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 December 31, 2015 , will be amortized into earnings through the final vesting period. We recorded compensation expense of $5.9 million and $0.2 million during the years ended December 31, 2015 and 2014, respectively, 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 the 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 year ended December 31, 2015, 9,353 phantom stock units were earned and 5,928 shares of common stock were issued to our board of directors. We recorded compensation expense of $1.9 million during the year ended December 31, 2015 related to the Deferred Compensation Plan. As of December 31, 2015 , there were 80,768 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 December 31, 2015 , 87,273 shares of SL Green's common stock had been issued under the ESPP.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 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 December 31, 2015 , 99,975,238 shares of common stock and no shares of excess stock were issued and outstanding. At-The-Market Equity Offering Program In July 2011, the Company, along with the Operating Partnership, entered into an "at-the-market" equity offering program, or ATM Program, to sell an aggregate of $250.0 million of SL Green's common stock. During the year ended December 31, 2014 , we sold 25,659 shares of our common stock out of the remaining balance of the ATM Program for aggregate net proceeds of $2.8 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 25,659 units of limited partnership interest of the Operating Partnership. 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 year ended December 31, 2014 , we sold 1,626,999 shares of our common stock for aggregate net proceeds of $182.9 million . The net proceeds from these offerings were contributed to the Operating Partnership in exchange for 1,626,999 units of limited partnership interest of the Operating Partnership. 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 year ended December 31, 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 December 31, 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. The following table summarizes SL Green common stock issued, and proceeds received from dividend reinvestments and/or stock purchases under the DRSPP for the year ended December 31, 2015, 2014, and 2013, respectively (in thousands): Year Ended December 31, 2015 2014 2013 Common Stock Shares Issued 775,760 608 761 Dividend reinvestments/stock purchases under the DRSPP $ 99,555 $ 64 $ 67 Earnings per Share SL Green's earnings per share for the years ended December 31, 2015 , 2014 , and 2013 are computed as follows (in thousands): Year Ended December 31, Numerator 2015 2014 2013 Basic Earnings: Income attributable to SL Green common stockholders $ 269,132 $ 503,104 $ 101,330 Effect of Dilutive Securities: Redemption of units to common shares 10,565 18,467 3,023 Diluted Earnings: Income attributable to SL Green common stockholders $ 279,697 $ 521,571 $ 104,353 Year Ended December 31, Denominator 2015 2014 2013 Basic Shares: Weighted average common stock outstanding 99,345 95,774 92,269 Effect of Dilutive Securities: Redemption of units to common shares 3,899 3,514 2,735 Stock-based compensation plans 490 408 262 Diluted weighted average common stock outstanding 103,734 99,696 95,266 SL Green has excluded 263,991 , 737,361 , and 964,789 common stock equivalents from the diluted shares outstanding for the years ended December 31, 2015 , 2014 , and 2013 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 The following tables set forth the changes in accumulated other comprehensive income (loss) by component as of December 31, 2015 , 2014 and 2013 (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, 2012 $ (16,834 ) $ (16,063 ) $ 3,310 $ (29,587 ) Other comprehensive (loss) income before reclassifications (168 ) 6,267 1,474 7,573 Amounts reclassified from accumulated other comprehensive income 1,877 4,926 — 6,803 Balance at December 31, 2013 (15,125 ) (4,870 ) 4,784 (15,211 ) Other comprehensive (loss) income before reclassifications (576 ) 2,847 (2,692 ) (421 ) Amounts reclassified from accumulated other comprehensive income 6,203 1,928 521 8,652 Balance at December 31, 2014 (9,498 ) (95 ) 2,613 (6,980 ) Other comprehensive loss before reclassifications (11,143 ) (1,714 ) (610 ) (13,467 ) Amounts reclassified from accumulated other comprehensive income 10,481 1,217 — 11,698 Balance at December 31, 2015 $ (10,160 ) $ (592 ) $ 2,003 $ (8,749 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of December 31, 2015 and 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 $9.7 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.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 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 consists 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 Total Level 1 Level 2 Level 3 Assets: Marketable securities $ 45,138 $ 4,704 $ 40,434 $ — Interest rate cap and swap agreements (included in other assets) $ 204 $ — $ 204 $ — Liabilities: Interest rate cap swap agreements (included in accrued interest payable and other liabilities) $ 10,776 $ — $ 10,776 $ — 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 December 31, 2015 and December 31, 2014 (in thousands): December 31, 2015 December 31, 2014 Carrying Value Fair Value Carrying Value Fair Value Debt and preferred equity investments $ 1,670,020 (1) $ 1,408,804 (1) Fixed rate debt $ 7,232,254 $ 7,591,388 $ 6,140,786 $ 6,565,236 Variable rate debt (2) 3,202,494 3,179,186 2,291,943 2,315,952 $ 10,434,748 $ 10,770,574 $ 8,432,729 $ 8,881,188 ____________________________________________________________________ (1) At December 31, 2015 , debt and preferred equity investments had an estimated fair value ranging between $1.7 billion and $1.8 billion . At December 31, 2014, debt and preferred equity investments had an estimated fair value ranging between $1.5 billion and $1.8 billion . (2) Includes the $29.0 million mortgage at 248-252 Bedford Avenue that is included in liabilities related to assets held for sale on the consolidated balance sheets at December 31, 2015. Includes the $253.9 million mortgage at 180 Maiden Lane that is included in liabilities related to assets held for sale on the consolidated balance sheets at December 31, 2014. Disclosure about fair value of financial instruments was based on pertinent information available to us as of December 31, 2015 and 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	12 Months Ended
	Dec. 31, 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 December 31, 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 Assets — Interest Rate Cap - Sold 500,000 4.750 % November 2014 May 2016 Other Liabilities — Interest Rate Cap 446,000 4.750 % October 2014 May 2016 Other Assets — Interest Rate Swap 200,000 0.938 % October 2014 December 2017 Other Assets 71 Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Assets 47 Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Assets 47 Interest Rate Swap 144,000 2.236 % December 2012 December 2017 Other Liabilities (3,516 ) Interest Rate Swap 86,400 1.948 % December 2012 December 2017 Other Liabilities (1,630 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (1,862 ) Interest Rate Swap 72,000 1.345 % December 2012 December 2017 Other Liabilities (522 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (1,859 ) Interest Rate Swap 57,600 1.990 % December 2012 December 2017 Other Liabilities (1,134 ) Interest Rate Swap 30,000 2.295 % July 2010 June 2016 Other Liabilities (241 ) Interest Rate Swap 14,409 0.500 % January 2015 January 2017 Other Assets 36 Interest Rate Swap 8,018 0.852 % February 2015 February 2017 Other Liabilities (12 ) Interest Rate Cap 137,500 4.000 % September 2015 September 2017 Other Assets 3 $ (10,572 ) During the years ended December 31, 2015, 2014, and 2013 , we recorded a gain on the changes in the fair value of $15,000 , $61,000 , and $16,000 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 December 31, 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 $11.3 million . As of December 31, 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 $11.3 million at December 31, 2015 . Gains and losses on terminated hedges are included in 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 $5.5 million of the current balance held in accumulated other comprehensive loss will be reclassified into interest expense and $0.7 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 years ended December 31, 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) Year Ended Year Ended Year Ended Derivative 2015 2014 2013 2015 2014 2013 2015 2014 2013 Interest Rate Swaps/Caps $ (11,607 ) $ (703 ) $ (68 ) Interest expense $ 10,892 $ 6,431 $ 1,933 Interest expense $ (422 ) $ 4 $ 3 Share of unconsolidated joint ventures' derivative instruments (1,779 ) 2,916 6,553 Equity in net income from unconsolidated joint ventures 1,265 1,999 5,072 Equity in net income from unconsolidated joint ventures (19 ) — — $ (13,386 ) $ 2,213 $ 6,485 $ 12,157 $ 8,430 $ 7,005 $ (441 ) $ 4 $ 3

Rental Income

Rental Income	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Rental Income	Rental Income The Operating Partnership is the lessor and the sublessor to tenants under operating leases with expiration dates ranging from January 1, 2016 to 2064. The minimum rental amounts due under the leases are generally either subject to scheduled fixed increases or adjustments. The leases generally also require that the tenants reimburse us for increases in certain operating costs and real estate taxes above their base year costs. Approximate future minimum rents to be received over the next five years and thereafter for non-cancelable operating leases in effect at December 31, 2015 for the consolidated properties, including consolidated joint venture properties, and our share of unconsolidated joint venture properties are as follows (in thousands): Consolidated Properties Unconsolidated Properties 2016 $ 1,181,279 $ 175,027 2017 1,162,046 181,804 2018 1,087,356 177,630 2019 996,282 167,695 2020 940,948 158,575 Thereafter 6,780,451 958,010 $ 12,148,362 $ 1,818,741

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	Benefit Plans The building employees are covered by multi-employer defined benefit pension plans and post-retirement health and welfare plans. We participate in the Building Service 32BJ, or Union, Pension Plan and Health Plan. The Pension Plan is a multi-employer, non-contributory defined benefit pension plan that was established under the terms of collective bargaining agreements between the Service Employees International Union, Local 32BJ, the Realty Advisory Board on Labor Relations, Inc. and certain other employees. This Pension Plan is administered by a joint board of trustees consisting of union trustees and employer trustees and operates under employer identification number 13-1879376. The Pension Plan year runs from July 1 to June 30. Employers contribute to the Pension Plan at a fixed rate on behalf of each covered employee. Separate actuarial information regarding such pension plans is not made available to the contributing employers by the union administrators or trustees, since the plans do not maintain separate records for each reporting unit. However, on September 28, 2013, September 30, 2014, and September 28, 2015, the actuary certified that for the plan years beginning July 1, 2013, July 1, 2014, and July 1, 2015, respectively, the Pension Plan was in critical status under the Pension Protection Act of 2006. The Pension Plan trustees adopted a rehabilitation plan consistent with this requirement. No surcharges have been paid to the Pension Plan as of December 31, 2015 . The Pension Plan received contributions from employers totaling $242.3 million , $226.7 million and $221.9 million , for the plan years beginning July 1, 2012, July 2013 and July 2014, respectively. The Health Plan was established under the terms of collective bargaining agreements between the Union, the Realty Advisory Board on Labor Relations, Inc. and certain other employers. The Health Plan provides health and other benefits to eligible participants employed in the building service industry who are covered under collective bargaining agreements, or other written agreements, with the Union. The Health Plan is administered by a Board of Trustees with equal representation by the employers and the Union and operates under employer identification number 13-2928869. The Health Plan receives contributions in accordance with collective bargaining agreements or participation agreements. Generally, these agreements provide that the employers contribute to the Health Plan at a fixed rate on behalf of each covered employee. For the Health plan years ended, June 30, 2015, 2014 , and 2013 , the plan received contributions from employers totaling $1.1 billion , $1.0 billion , and $923.5 million , respectively. Our contributions to the Health Plan represent less than 5.0% of total contributions to the plan. Contributions we made to the multi-employer plans for the years ended December 31, 2015 , 2014 and 2013 are included in the table below (in thousands): Benefit Plan 2015 2014 2013 Pension Plan $ 2,732 $ 2,807 $ 2,765 Health Plan 8,736 8,470 8,522 Other plans 5,716 5,838 6,006 Total plan contributions $ 17,184 $ 17,115 $ 17,293 401(K) Plan In August 1997, we implemented a 401(K) Savings/Retirement Plan, or the 401(K) Plan, to cover eligible employees of ours, and any designated affiliate. The 401(K) Plan permits eligible employees to defer up to 15% of their annual compensation, subject to certain limitations imposed by the Code. The employees' elective deferrals are immediately vested and non-forfeitable upon contribution to the 401(K) Plan. During 2000, we amended our 401(K) Plan to include a matching contribution, subject to ERISA limitations, equal to 50% of the first 4% of annual compensation deferred by an employee. During 2003, we amended our 401(K) Plan to provide for discretionary matching contributions only. For 2015 , 2014 and 2013 , a matching contribution equal to 50% of the first 6% of annual compensation was made. For each of the years ended December 31, 2015 , 2014 and 2013 , we made matching contributions of $550,000 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings As of December 31, 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. Employment Agreements We have entered into employment agreements with certain executives, which expire between January 2016 and January 2019. The minimum cash-based compensation, including base salary and guaranteed bonus payments, associated with these employment agreements total $5.0 million for 2016. In addition these employment agreements provide for deferred compensation awards based on our stock price and which were valued at $1.5 million on the grant date. The value of these awards may change based on fluctuations in our stock price. Insurance We maintain “all-risk” property and rental value coverage (including coverage regarding the perils of flood, earthquake and terrorism) within three property insurance portfolios and liability insurance. The first property portfolio maintains a blanket limit of $950.0 million per occurrence, including terrorism, for the majority of the New York City properties in our portfolio and expires December 31, 2017. The second portfolio maintains a limit of $1.5 billion per occurrence, including terrorism, for several New York City properties and the majority of the Suburban properties and expires December 31, 2017. Each of these policies includes $100.0 million of flood coverage, with a lower sublimit for locations in high hazard flood zones. A third blanket property policy covers most of our residential assets and maintains a limit of $380.1 million per occurrence, including terrorism, for our residential properties and expires January 31, 2018. We maintain two liability policies which cover all our properties and provide limits of $201.0 million per occurrence and in the aggregate per location. The liability policies expire on October 31, 2016 and January 31, 2017 and cover our commercial and residential assets, respectively. Additional coverage may be purchased on a stand-alone basis for certain assets. In October 2006, we formed a wholly-owned taxable REIT subsidiary, Belmont, to act as a captive insurance company and as one of the elements of our overall insurance program. Belmont is a subsidiary of ours. Belmont was formed in an effort to, among other reasons, stabilize the fluctuations of insurance market conditions. Belmont is licensed in New York to write Terrorism, NBCR (nuclear, biological, chemical, and radiological), General Liability, Environmental Liability and D&O coverage. On January 12, 2015, the Terrorism Risk Insurance Program Reauthorization and Extension Act of 2007 (TRIPRA) (formerly the Terrorism Risk Insurance Act) was reauthorized until December 31, 2020 pursuant to the Terrorism Insurance Program Reauthorization and Extension Act of 2015. The TRIPRA extends the federal Terrorism Insurance Program that requires insurance companies to offer terrorism coverage and provides for compensation for insured losses resulting from acts of certified terrorism, subject to the current program trigger of $100.0 million , which will increase by $20 million per annum, commencing December 31, 2015. Our debt instruments, consisting of mortgage loans secured by our properties (which are generally non-recourse to us), mezzanine loans, ground leases, our 2012 credit facility, senior unsecured notes and other corporate obligations, contain customary covenants requiring us to maintain insurance. Although we believe that we currently maintain sufficient insurance coverage to satisfy these obligations, there is no assurance that in the future we will be able to procure coverage at a reasonable cost. In such instances, there can be no assurance that the lenders or ground lessors under these instruments will not take the position that a total or partial exclusion from “all-risk” insurance coverage for losses due to terrorist acts is a breach of these debt and ground lease instruments allowing the lenders or ground lessors to declare an event of default and accelerate repayment of debt or recapture of ground lease positions. In addition, if lenders prevail in asserting that we are required to maintain full coverage for these risks, it could result in substantially higher insurance premiums. We own Belmont and the accounts of Belmont are part of our consolidated financial statements. If Belmont experiences a loss and is required to pay under its insurance policy, we would ultimately record the loss to the extent of Belmont’s required payment. Therefore, insurance coverage provided by Belmont should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance. We monitor all properties that are subject to triple net leases to ensure that tenants are providing adequate coverage. Certain joint ventures may be covered under policies separate from our policies, at coverage limits which we deem to be adequate. We continually monitor these policies. Although we consider our insurance coverage to be appropriate, in the event of a major catastrophe, we may not have sufficient coverage to replace certain properties. Belmont had loss reserves of $6.4 million and $6.1 million as of December 31, 2015 and 2014 , respectively. Capital and Ground Leases Arrangements In 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 . In November 2013, we renewed and extended the maturity date of the ground lease at 420 Lexington Avenue from December 31, 2029 through December 31, 2050, with two options for further extension through December 2085. Ground lease rent payments will be $10.9 million annually through December 2019, $ 11.2 million annually through December 2029 and then beginning in January 2030 through the remaining lease term, a minimum annual rent of $ 12.3 million , subject to a one-time adjustment based on 6% of the fair value of the land. In October 2012, we, together with Stonehenge Partners, acquired a leasehold position at 1080 Amsterdam Avenue. The joint venture prepaid $13.0 million of ground lease rent, which will be applied against rental payments over the term of the lease. The lease will expire on July 31, 2111 or earlier in accordance with the terms of the lease agreement. Land was estimated to be of the fair market value of the property. The portion of the lease attributed to land was classified as an operating lease and the remainder as a capital lease which had a cost basis of $27.4 million and accumulated amortization of $0.4 million as of December 31, 2015 . The property located at 711 Third Avenue operates under an operating sub-lease, which expires in 2083. The ground rent was reset in July 2011. Following the reset, we are responsible for ground rent payments of $5.25 million annually through July 2016 and then $5.5 million annually thereafter on the 50% portion of the fee that we do not own. The property located at 461 Fifth Avenue operates under a ground lease ( $2.1 million of ground rent annually) with an expiration date of 2027 and two options to renew for an additional 21 years each, followed by a third option for 15 years. We also have an option to purchase the fee position for a fixed price on a specific date. The property located at 625 Madison Avenue operates under a ground lease ( $4.6 million of ground rent annually) with an expiration date of 2022 and two options to renew for an additional 23 years. The property located at 1185 Avenue of the Americas operates under a ground lease ( $6.9 million of ground rent annually) with an expiration of 2043 and an option to renew for an additional 23 years. 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 December 31, 2015 (in thousands): Capital lease Non-cancellable operating leases 2016 $ 2,266 $ 30,816 2017 2,387 31,049 2018 2,387 31,049 2019 2,411 31,066 2020 2,620 31,436 Thereafter 825,483 764,352 Total minimum lease payments 837,554 $ 919,768 Less amount representing interest (796,194 ) Capital lease obligations $ 41,360

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 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 years ended December 31, 2015 , 2014 , and 2013 , and selected asset information as of December 31, 2015 and 2014 , regarding our operating segments are as follows (in thousands): Real Estate Segment Debt and Preferred Equity Segment Total Company Total revenues Years ended: December 31, 2015 $ 1,481,701 $ 181,128 $ 1,662,829 December 31, 2014 1,341,163 178,815 1,519,978 December 31, 2013 1,177,222 193,843 1,371,065 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 depreciable real estate reserves Years ended: December 31, 2015 $ (63,345 ) $ 153,585 $ 90,240 December 31, 2014 22,178 150,852 173,030 December 31, 2013 (49,793 ) 159,193 109,400 Total assets As of: December 31, 2015 $ 18,175,665 $ 1,682,276 $ 19,857,941 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 $94.9 million , $92.5 million , and $86.2 million for the years ended December 31, 2015 , 2014 , and 2013 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 years ended December 31, 2015 , 2014 , and 2013 (in thousands): Year ended December 31, 2015 2014 2013 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 depreciable real estate reserves $ 90,240 $ 173,030 $ 109,400 Equity in net gain on sale of interest in unconsolidated joint venture/real estate 15,844 123,253 3,601 Purchase price fair value adjustment 40,078 67,446 (2,305 ) Gain on sale of real estate 175,974 — — Depreciable real estate reserves (19,226 ) — — Income from continuing operations 302,910 363,729 110,696 Net income from discontinued operations 427 19,075 25,687 Gain on sale of discontinued operations 14,122 163,059 14,900 Net income $ 317,459 $ 545,863 $ 151,283

Quarterly Financial Data of the

Quarterly Financial Data of the Company (unaudited)	12 Months Ended
	Dec. 31, 2015
SL Green Realty Corp
Condensed Income Statements, Captions [Line Items]
Quarterly Financial Data of the Company/Operating Partnership (unaudited)	Quarterly Financial Data of the Company (unaudited) Summarized quarterly financial data for the years ended December 31, 2015 and 2014 , which is reflective of the reclassification of the properties sold or held for sale during 2015 and 2014 as discontinued operations (see Note 4, "Properties Held for Sale and Dispositions"), was as follows (in thousands, except for per share amounts): 2015 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 425,390 $ 432,066 $ 409,074 $ 396,299 Income from continuing operations before equity in net (loss) gain, 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 47,760 11,637 (36,137 ) 33,654 Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate (206 ) 15,281 769 — Purchase price fair value adjustment 40,078 — — — Gain on sale of real estate 16,270 159,704 — — Depreciable real estate reserves — (19,226 ) — — Loss on early extinguishment of debt — — — (49 ) Net income from discontinued operations — — — 427 Gain on sale of discontinued operations 1,139 — — 12,983 Net income (loss) attributable to SL Green 105,041 — 167,396 — (35,368 ) 47,015 Perpetual preferred stock dividends (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income (loss) attributable to SL Green common stockholders $ 101,303 $ 163,658 $ (39,106 ) $ 43,277 Net income (loss) attributable to common stockholders per common share—basic $ 1.02 $ 1.64 $ (0.39 ) $ 0.44 Net income (loss) attributable to common stockholders per common share—diluted $ 1.01 $ 1.64 $ (0.39 ) $ 0.44 2014 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 386,627 $ 390,274 $ 380,631 $ 362,446 Income from continuing before equity in net gain on sale of interest in unconsolidated joint venture/real estate, (loss) gain on early extinguishment of debt, gain on sale of investment in marketable securities, net of noncontrolling interests $ 40,379 $ 46,863 $ 47,035 $ 39,416 Equity in net gain on sale of interest in unconsolidated joint venture/ real estate 673 16,496 1,444 104,640 Purchase price fair value adjustment — (4,000 ) 71,446 — (Loss) gain on early extinguishment of debt (6,865 ) (24,475 ) (1,028 ) 3 Gain on sale of investment in marketable securities 3,895 — — — Net income from discontinued operations 3,626 4,035 5,645 5,769 Gain on sale of discontinued operations 18,817 29,507 114,735 — Net income attributable to SL Green 60,525 68,426 239,277 149,828 Perpetual preferred stock dividends (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income attributable to SL Green common stockholders $ 56,787 $ 64,688 $ 235,539 $ 146,090 Net income attributable to common stockholders per common share—basic $ 0.59 $ 0.68 $ 2.47 $ 1.54 Net income attributable to common stockholders per common share—diluted $ 0.59 $ 0.68 $ 2.46 $ 1.53

Quarterly Financial Data of t35

Quarterly Financial Data of the Operating Partnership (unaudited)	12 Months Ended
	Dec. 31, 2015
SL Green Operating Partnership
Condensed Income Statements, Captions [Line Items]
Quarterly Financial Data of the Company/Operating Partnership (unaudited)	Quarterly Financial Data of the Operating Partnership (unaudited) Summarized quarterly financial data for the years ended December 31, 2015 and 2014 , which is reflective of the reclassification of the properties sold or held for sale during 2015 and 2014 as discontinued operations (see Note 4, "Properties Held for Sale and Dispositions"), was as follows (in thousands, except for per share amounts): 2015 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 425,390 $ 432,066 $ 409,074 $ 396,299 Income (loss) from continuing operations before equity in net (loss) 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 $ 51,691 $ 18,104 $ (37,714 ) $ 35,397 Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate (206 ) 15,281 769 — Purchase price fair value adjustment 40,078 — — — Gain on sale of real estate 16,270 159,704 — — Depreciable real estate reserves — (19,226 ) — — Loss on early extinguishment of debt — — — (49 ) Net income from discontinued operations — — — 427 Gain on sale of discontinued operations 1,139 — — 12,983 Net income attributable to SLGOP 108,972 173,863 (36,945 ) 48,758 Perpetual preferred units distributions (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income (loss) attributable to SLGOP common unitholders $ 105,234 $ 170,125 $ (40,683 ) $ 45,020 Net income (loss) attributable to common unitholders per common unit—basic $ 1.02 $ 1.64 $ (0.39 ) $ 0.44 Net income (loss) attributable to common unitholders per common unit—diluted $ 1.01 $ 1.64 $ (0.39 ) $ 0.44 2014 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 386,627 $ 390,274 $ 380,631 $ 362,446 Income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate, (loss) gain on early extinguishment of debt, gain on sale of investment in marketable securities, net of noncontrolling interests $ 42,837 $ 49,499 $ 55,680 $ 44,144 Equity in net gain on sale of interest in unconsolidated joint venture/ real estate 673 16,496 1,444 104,640 Purchase price fair value adjustment — (4,000 ) 71,446 — Gain (loss) on early extinguishment of debt (6,865 ) (24,475 ) (1,028 ) 3 Gain on sale of investment in marketable securities 3,895 — — — Net income from discontinued operations 3,626 4,035 5,645 5,769 Gain on sale of discontinued operations 18,817 29,507 114,735 — Net income attributable to SLGOP 62,983 71,062 247,922 154,556 Perpetual preferred distributions (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income attributable to SLGOP common unitholders $ 59,245 $ 67,324 $ 244,184 $ 150,818 Net income attributable to common unitholders per common unit—basic $ 0.59 $ 0.68 $ 2.47 $ 1.54 Net income attributable to common unitholders per common unit—diluted $ 0.59 $ 0.68 $ 2.46 $ 1.53

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts	Column A Column B Column C Column D Column E Description Balance at Beginning of Year Additions Charged Against Operations Uncollectible Accounts Written-off/Recovery Balance at End of Year Year Ended December 31, 2015 Tenant and other receivables—allowance $ 18,068 $ 8,139 $ (8,589 ) $ 17,618 Deferred rent receivable—allowance $ 27,411 $ 2,789 $ (8,470 ) $ 21,730 Year Ended December 31, 2014 Tenant and other receivables—allowance $ 17,325 $ 13,533 $ (12,790 ) $ 18,068 Deferred rent receivable—allowance $ 30,333 $ 4,140 $ (7,062 ) $ 27,411 Year Ended December 31, 2013 Tenant receivables—allowance $ 14,341 $ 13,425 $ (10,441 ) $ 17,325 Deferred rent receivable—allowance $ 29,580 $ 7,563 $ (6,810 ) $ 30,333

Schedule III - Real Estate And

Schedule III - Real Estate And Accumulated Depreciation	12 Months Ended
	Dec. 31, 2015
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Real Estate And Accumulated Depreciation	Column A Column B Column C Initial Cost Column D Cost Capitalized Subsequent To Acquisition Column E Gross Amount at Which Carried at Close of Period Column F Column G Column H Column I Description Encumbrances Land Building & Improvements Land Building & Improvements Land Building & Improvements Total Accumulated Depreciation Date of Construction Date Acquired Life on Which Depreciation is Computed 420 Lexington Ave(1) 300,000 — 107,832 — 233,845 — 341,677 341,677 123,717 1927 3/1998 Various 711 Third Avenue(1)(7) — 19,844 42,499 — 38,618 19,844 81,117 100,961 29,741 1955 5/1998 Various 555 W. 57th Street(1) — 18,846 78,704 — 50,261 18,846 128,965 147,811 53,036 1971 1/1999 Various 317 Madison Ave(1) — 21,205 85,559 (21,205 ) (85,559 ) — — — — 1920 6/2001 Various 220 East 42nd Street(1) 275,000 50,373 203,727 635 64,648 51,008 268,375 319,383 90,072 1929 2/2003 Various 461 Fifth Avenue(1) — — 62,695 — 11,527 — 74,222 74,222 24,449 1988 10/2003 Various 750 Third Avenue(1) — 51,093 205,972 — 37,283 51,093 243,255 294,348 78,460 1958 7/2004 Various 625 Madison Ave(1) — — 246,673 — 38,779 — 285,452 285,452 87,625 1956 10/2004 Various 485 Lexington Avenue(1) 450,000 77,517 326,825 765 88,570 78,282 415,395 493,677 140,556 1956 12/2004 Various 609 Fifth Avenue(1) — 36,677 145,954 — 8,157 36,677 154,111 190,788 37,473 1925 6/2006 Various 120 West 45th Street(1) — 60,766 250,922 (60,766 ) (250,922 ) — — — — 1998 1/2007 Various 810 Seventh Avenue(1) — 114,077 476,386 — 65,604 114,077 541,990 656,067 131,946 1970 1/2007 Various 919 Third Avenue(1)(2) 500,000 223,529 1,033,198 35,410 27,639 258,939 1,060,837 1,319,776 245,932 1970 1/2007 Various 1185 Avenue of the Americas(1) — — 728,213 — 36,857 — 765,070 765,070 198,483 1969 1/2007 Various 1350 Avenue of the Americas(1) — 91,038 380,744 — 32,612 91,038 413,356 504,394 102,335 1966 1/2007 Various 1100 King Street— 1-7 International Drive(3) — 49,392 104,376 2,473 17,612 51,865 121,988 173,853 31,007 1983/1986 1/2007 Various 520 White Plains Road(3) — 6,324 26,096 — 6,720 6,324 32,816 39,140 8,617 1979 1/2007 Various 115-117 Stevens Avenue(3) — 5,933 23,826 — 5,797 5,933 29,623 35,556 7,916 1984 1/2007 Various 100 Summit Lake Drive(3) — 10,526 43,109 — 7,402 10,526 50,511 61,037 13,567 1988 1/2007 Various 200 Summit Lake Drive(3) — 11,183 47,906 — 8,223 11,183 56,129 67,312 14,714 1990 1/2007 Various 500 Summit Lake Drive(3) — 9,777 39,048 — 5,456 9,777 44,504 54,281 10,557 1986 1/2007 Various 140 Grand Street(3) — 6,865 28,264 (6,865 ) (28,264 ) — — — — 1991 1/2007 Various 360 Hamilton Avenue(3) — 29,497 118,250 — 12,515 29,497 130,765 160,262 31,927 2000 1/2007 Various 1-6 Landmark Square(4) 79,562 50,947 195,167 — 36,803 50,947 231,970 282,917 54,477 1973-1984 1/2007 Various 7 Landmark Square(4) — 2,088 7,748 (367 ) 84 1,721 7,832 9,553 799 2007 1/2007 Various 680 Washington Boulevard(2)(4) — 11,696 45,364 — 5,818 11,696 51,182 62,878 12,783 1989 1/2007 Various 750 Washington Boulevard(2)(4) — 16,916 68,849 — 6,459 16,916 75,308 92,224 17,391 1989 1/2007 Various 1010 Washington Boulevard(4) — 7,747 30,423 — 5,223 7,747 35,646 43,393 8,732 1988 1/2007 Various 500 West Putnam Avenue(4) 22,376 11,210 44,782 — 5,054 11,210 49,836 61,046 11,684 1973 1/2007 Various 150 Grand Street(3) — 1,371 5,446 (1,371 ) (5,446 ) — — — — 1962 1/2007 Various 400 Summit Lake Drive(3) — 38,889 1 285 — 39,174 1 39,175 1 --- 1/2007 N/A 331 Madison Avenue(1) — 14,763 65,241 (14,763 ) (65,241 ) — — — — 1923 4/2007 Various 1055 Washington Boulevard(4) — 13,516 53,228 — 5,297 13,516 58,525 72,041 13,747 1987 6/2007 Various 1 Madison Avenue(1) 542,817 172,641 654,394 905 15,261 173,546 669,655 843,201 141,854 1960 8/2007 Various Column A Column B Column C Initial Cost Column D Cost Capitalized Subsequent To Acquisition Column E Gross Amount at Which Carried at Close of Period Column F Column G Column H Column I Description Encumbrances Land Building & Improvements Land Building & Improvements Land Building & Improvements Total Accumulated Depreciation Date of Construction Date Acquired Life on Which Depreciation is Computed 125 Chubb Way(5) — 5,884 25,958 — 24,482 5,884 50,440 56,324 7,200 2008 1/2008 Various 100 Church Street(1) 225,099 32,494 79,996 2,500 87,286 34,994 167,282 202,276 33,564 1959 1/2010 Various 125 Park Avenue(1) — 120,900 189,714 — 55,365 120,900 245,079 365,979 43,887 1923 10/2010 Various 885 Third Avenue(1) 267,650 131,766 — 110,771 — 242,537 — 242,537 — --- 12/2010 N/A Williamsburg(6) — 3,677 14,708 2,523 (4,550 ) 6,200 10,158 16,358 1,343 2010 12/2010 Various 1515 Broadway(1) 900,000 462,700 707,938 1,145 102,335 463,845 810,273 1,274,118 112,497 1972 4/2011 Various 110 East 42nd Street(1) — 34,000 46,411 2,354 19,165 36,354 65,576 101,930 12,397 1921 5/2011 Various 51 East 42nd Street(1) — 44,095 33,470 (44,095 ) (33,470 ) — — — — 1913 11/2011 Various 400 East 57th Street(1)(11) 67,644 39,780 69,895 — 14,136 39,780 84,031 123,811 7,534 1931 1/2012 Various 400 East 58th Street(1)(11) 28,990 17,549 30,916 — 6,217 17,549 37,133 54,682 3,291 1929 1/2012 Various 752 Madison Avenue(1)(8) — 282,415 7,131 1,871 10 284,286 7,141 291,427 858 1996/2012 1/2012 Various 762 Madison Avenue(1)(11) 7,872 6,153 10,461 — 90 6,153 10,551 16,704 1,083 1910 1/2012 Various 19-21 East 65th Street(1)(11) — — 7,389 — 159 — 7,548 7,548 753 1928-1940 1/2012 Various 304 Park Avenue(1) — 54,189 75,619 300 8,122 54,489 83,741 138,230 10,341 1930 6/2012 Various 635 Sixth Avenue(1) — 24,180 37,158 163 49,534 24,343 86,692 111,035 1,462 1902 9/2012 Various 641 Sixth Avenue(1) — 45,668 67,316 308 1,888 45,976 69,204 115,180 7,308 1902 9/2012 Various 1080 Amsterdam(1)(9) 3,525 — 27,445 — 20,405 — 47,850 47,850 1,766 1932 10/2012 Various 131-137 Spring Street(1)(10) — 27,021 105,342 (27,021 ) (105,342 ) — — — — 1891 12/2012 Various 248-252 Bedford Avenue(6)(11) 29,000 10,865 44,035 (10,865 ) (43,672 ) — 363 363 — 2012 3/2013 Various 16 Court Street(6) — 19,217 63,210 — 10,854 19,217 74,064 93,281 7,393 1927-1928 4/2013 Various 315 West 33rd Street (1) — 195,834 164,429 — 6,173 195,834 170,602 366,436 10,246 2000-2001 11/2013 Various 562 Fifth Avenue(1) — 57,052 10,487 1,213 57,052 11,700 68,752 1,874 1909/1920/1921 11/2013 Various 388-390 Greenwich Street(1) 1,450,000 516,292 964,434 — 140,275 516,292 1,104,709 1,621,001 48,195 1986/1990 5/2014 Various 719 Seventh Avenue(1)(12) — 41,850 — 500 6,107 42,350 6,107 48,457 — 1927 7/2014 Various 115 Spring Street(1) — 11,078 44,799 — 247 11,078 45,046 56,124 1,788 1900 7/2014 Various 635 Madison(1) — 205,632 15,805 — — 205,632 15,805 221,437 515 9/2014 N/A 102 Greene Street(1) — 8,215 26,717 — 277 8,215 26,994 35,209 847 1910 11/2014 Various 1640 Flatbush Avenue (6) — 6,120 680 — — 6,120 680 6,800 13 1966 3/2015 Various One Vanderbilt (1)(13) — 80,069 116,557 — 31,095 80,069 147,652 227,721 — N/A 6/2001 - 11/2011 Various Upper East Side Residential (1)(11) — 17,500 32,500 26 48 17,526 32,548 50,074 450 1930 6/2015 Various 110 Greene Street (1)(11) — 89,250 165,750 — 324 89,250 166,074 255,324 1,827 1910 7/2015 Various 11 Madison Ave (1) 1,400,000 849,926 1,579,118 — 66,007 849,926 1,645,125 2,495,051 11,020 1929 8/2015 Various 187 Broadway (1) 8,400 4,707 8,741 — — 4,707 8,741 13,448 799 1969 8/2015 Various 5-7 Dey Street (1) 31,600 17,394 32,304 — — 17,394 32,304 49,698 2,953 1921 8/2015 Various 30 East 40th Street (1) — 4,650 20,000 — — 4,650 20,000 24,650 82 1927 8/2015 Various 600 Lexington Avenue (1)(14) 112,795 97,044 180,224 — — 97,044 180,224 277,268 288 1983 12/2015 Various Other (15) — 2,130 10,894 — — 2,130 10,894 13,024 3,534 Various Total $ 6,702,330 $ 4,803,542 $ 10,994,972 $ (24,384 ) $ 907,472 $ 4,779,158 $ 11,902,444 $ 16,681,602 $ 2,060,706 ______________________________________________________________________ (1) Property located in New York, New York. (2) We own a 51.0% interest in this property. (3) Property located in Westchester County, New York. (4) Property located in Connecticut. (5) Property located in New Jersey. (6) Property located in Brooklyn, New York. (7) We own a 50.0% interest in this property. (8) We own an 80.0% interest in this property. (9) We own a 92.5% interest in this property. (10) We own a 20.0% interest in this property. (11) We own a 90.0% interest in this property. (12) We own a 75.0% interest in this property. (13) Properties at 317 Madison Avenue, 331 Madison Avenue and 51 East 42nd Street were demolished in preparation of the development site for the One Vanderbilt project. (14) In May 2010 we acquired a 55.0% interest in this property for $193.0 million . In December 2015 we acquired the additional 45.0% interest in this property, thereby consolidating full ownership of the property. The December 2015 transaction valued the consolidated interests at $277.3 million . (15) Other includes tenant improvements of eEmerge, capitalized interest and corporate improvements. The changes in real estate for the years ended December 31, 2015 , 2014 and 2013 are as follows (in thousands): 2015 2014 2013 Balance at beginning of year $ 14,069,141 $ 12,333,780 $ 11,662,953 Property acquisitions 3,064,137 2,428,259 702,717 Improvements 396,555 379,295 199,141 Retirements/disposals/deconsolidation (848,231 ) (1,072,193 ) (231,031 ) Balance at end of year $ 16,681,602 $ 14,069,141 $ 12,333,780 The aggregate cost of land, buildings and improvements, before depreciation, for Federal income tax purposes at December 31, 2015 was $12.4 billion (unaudited). The changes in accumulated depreciation, exclusive of amounts relating to equipment, autos, and furniture and fixtures, for the years ended December 31, 2015 , 2014 and 2013 are as follows (in thousands): 2015 2014 2013 Balance at beginning of year $ 1,905,165 $ 1,646,240 $ 1,393,323 Depreciation for year 480,523 307,823 286,776 Retirements/disposals/deconsolidation (324,982 ) (48,898 ) (33,859 ) Balance at end of year $ 2,060,706 $ 1,905,165 $ 1,646,240

Significant Accounting Polici38

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 are $200.7 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 December 31, 2015 and 2014 are $104.5 million and $106.5 million , respectively, related to our consolidated VIEs. As of December 31, 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 requiring 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 Real estate properties are presented at cost less accumulated depreciation and amortization. Costs directly related to the development or redevelopment of properties are capitalized. Ordinary repairs and maintenance are expensed as incurred; major replacements and betterments, which improve or extend the life of the asset, are capitalized and depreciated over their estimated useful lives. A property to be disposed of is reported at the lower of its carrying value or its estimated fair value, less its cost to sell. Once an asset is held for sale, depreciation expense is no longer recorded. The Company adopted ASU 2014-08 effective January 1, 2015. As a result, the Company classified 248-252 Bedford Avenue as held for sale as of December 31, 2015, 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. See Note 4, "Properties Held for Sale and Dispositions." Properties are depreciated using the straight-line method over the estimated useful lives of the assets. The estimated useful lives are as follows: Category Term Building (fee ownership) 40 years Building improvements shorter of remaining life of the building or useful life Building (leasehold interest) lesser of 40 years or remaining term of the lease Property under capital lease remaining lease term Furniture and fixtures four to seven years Tenant improvements shorter of remaining term of the lease or useful life Depreciation expense (including amortization of the capital lease asset) amounted to $523.8 million , $338.8 million and $296.5 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Included in 2015 is $131.8 million of accelerated depreciation expense related to vacating the properties that comprise the One Vanderbilt development site. 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. Except as discussed below, we do not believe that there were any indicators of impairment at any of our consolidated properties at December 31, 2015 . During the three months ended September 30, 2015, we recorded a $19.2 million charge in connection with the sale of two of our properties, which closed in the fourth quarter of 2015. 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." During the fourth quarter of 2015, we entered into an agreement to sell 885 Third Avenue and recorded a $6.6 million charge which was included in gain on sale of real estate, net in the consolidated statement of operations. As of December 31, 2015, 885 Third Avenue was not reclassified as held for sale as a result of not meeting the criteria in ASC 360-10, Property, Plant and Equipment - Impairment and Disposal of Long-Lived Assets. In February 2016, we closed on the sale of this property but do not anticipate meeting the criteria for the full accrual method in ASC 360-20, Property, Plant and Equipment - Real Estate Sales and as a result the property will remain on our consolidated balance sheet until the criteria is met. We incur a variety of costs in the development and leasing of our properties. After determination is made to capitalize a cost, it is allocated to the specific component of a project that is benefited. Determination of when a development project is substantially complete and capitalization must cease involves a degree of judgment. The costs of land and building under development include specifically identifiable costs. The capitalized costs include, but are not limited to, pre-construction costs essential to the development of the property, development costs, construction costs, interest costs, real estate taxes, salaries and related costs and other costs incurred during the period of development. We consider a construction project as substantially completed and held available for occupancy upon the completion of tenant improvements, but no later than one year after major construction activity ceases. We cease capitalization on the portions substantially completed and occupied or held available for occupancy, and capitalize only those costs associated with the portions under construction. Results of operations of properties acquired are included in the consolidated statements of operations from the date of acquisition. We recognize the assets acquired, liabilities assumed (including contingencies) and any noncontrolling interests in an acquired entity at their fair values on the acquisition date. We expense transaction costs related to the acquisition of certain assets as incurred, which are included in transaction related costs on our consolidated statements of operations. When we acquire our partner's equity interest in an existing unconsolidated joint venture and gain control over the investment, we record the consolidated investment at fair value. The difference between the book value of our equity investment on the purchase date and our share of the fair value of the investment's purchase price is recorded as a purchase price fair value adjustment in our consolidated statements of operations. In December 2015, we recognized a purchase price fair value adjustment of $40.1 million in connection with the consolidation of 600 Lexington Avenue. In May 2014, we recognized a purchase price fair value adjustment of $71.4 million in connection with the consolidation of 388-390 Greenwich Street. These acquisitions were previously accounted for as investments in unconsolidated joint ventures. 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.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly liquid investments with maturity of three months or less when purchased to be cash equivalents.
Fair Value Measurements	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. 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 consists 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.
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 December 31, 2015 , we did 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 account for our investments in unconsolidated joint ventures under the equity method of accounting in cases where we exercise significant influence over, but do not control, these entities and are not considered to be the primary beneficiary. We consolidate those joint ventures that we control or which are VIEs and where we are considered to be the primary beneficiary. In all these joint ventures, the rights of the joint venture partner are both protective as well as participating. Unless we are determined to be the primary beneficiary in a VIE, these participating rights preclude us from consolidating these VIE entities. These investments are recorded initially at cost, as investments in unconsolidated joint ventures, and subsequently adjusted for equity in net income (loss) and cash contributions and distributions. Equity in net income (loss) from unconsolidated joint ventures is allocated based on our ownership or economic interest in each joint venture. When a capital event (as defined in each joint venture agreement) such as a refinancing occurs, if return thresholds are met, future equity income will be allocated at our increased economic interest. We recognize incentive income from unconsolidated real estate joint ventures as income to the extent it is earned and not subject to a clawback feature. Distributions we receive from unconsolidated real estate joint ventures in excess of our basis in the investment are recorded as offsets to our investment balance if we remain liable for future obligations of the joint venture or may otherwise be committed to provide future additional financial support. None of the joint venture debt is recourse to us, except for $18.4 million , which we guarantee at one joint venture, and performance guarantees under master leases at two other joint ventures. See Note 6, "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 December 31, 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.
Restricted Cash	Restricted Cash Restricted cash primarily consists of security deposits held on behalf of our tenants, interest reserves, as well as capital improvement and real estate tax escrows required under certain loan agreements.
Deferred Lease Costs	Deferred Lease Costs Deferred lease costs consist of fees and direct costs incurred to initiate and renew operating leases and are amortized on a straight-line basis over the related lease term. Certain of our employees provide leasing services to the wholly-owned properties.
Deferred Financing Costs	Deferred Financing Costs Deferred financing costs represent commitment fees, legal, title and other third party costs associated with obtaining commitments for financing which result in a closing of such financing. These costs are amortized over the terms of the respective agreements. Unamortized deferred financing costs are expensed when the associated debt is refinanced or repaid before maturity. Costs incurred in seeking financing transactions, which do not close, are expensed in the period in which it is determined that the financing will not close.
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 provided that 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. Some 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 an adjustment 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 the loans individually. When a transaction meets the criteria for 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.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts We maintain an allowance for doubtful accounts for estimated losses resulting from the inability of our tenants to make required payments. If the financial condition of a specific tenant were to deteriorate, resulting in an impairment of its ability to make payments, additional allowances may be required.
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 include geographic trends, product diversification, the size of the portfolio and current economic conditions. Based upon these factors, we establish a provision for possible credit loss 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 additional information reflects increased recovery of our investment, we will adjust our reserves accordingly. There were no loan reserves recorded during years ended December 31, 2015 , 2014 , and 2013 . 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.
Rent Expense	Rent Expense Rent expense is recognized on a straight-line basis over the initial term of the lease. The excess of the rent expense recognized over the amounts contractually due pursuant to the underlying lease is included in the deferred land lease payable on the consolidated balance sheets.
Underwriting Commissions and Costs	Underwriting Commissions and Costs Underwriting commissions and costs incurred in connection with our stock offerings are reflected as a reduction of additional paid-in-capital.
Exchangeable Debt Instruments	Exchangeable Debt Instruments The initial proceeds from exchangeable debt that may be settled in cash, including partial cash settlements, are bifurcated between a liability component and an equity component associated with the embedded conversion option. The objective of the accounting guidance is to require the liability and equity components of exchangeable debt to be separately accounted for in a manner such that the interest expense on the exchangeable debt is not recorded at the stated rate of interest but rather at an effective rate that reflects the issuer's conventional debt borrowing rate at the date of issuance. We calculate the liability component of exchangeable debt based on the present value of the contractual cash flows discounted at our comparable market conventional debt borrowing rate at the date of issuance. The difference between the principal amount and the fair value of the liability component is reported as a discount on the exchangeable debt that is accreted as additional interest expense from the issuance date through the contractual maturity date using the effective interest method. A portion of this additional interest expense may be capitalized to the development and redevelopment balances qualifying for interest capitalization each period. The liability component of the exchangeable debt is reported net of discounts on our consolidated balance sheets. We calculate the equity component of exchangeable debt based on the difference between the initial proceeds received from the issuance of the exchangeable debt and the fair value of the liability component at the issuance date. The equity component is included in additional paid-in-capital, net of issuance costs, on our consolidated balance sheets. We allocate issuance costs for exchangeable debt between the liability and the equity components based on their relative values.
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 years ended December 31, 2015 , 2014 and 2013, we recorded Federal, state and local tax provisions of $3.1 million , $7.8 million and $4.4 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.
Derivative Instruments	Derivative Instruments 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. Effectiveness is essential for those derivatives that we intend to quality for hedge accounting. Some derivative instruments are associated with an anticipated transaction. In those cases, hedge effectiveness criteria also require that it be probable that the underlying transaction occurs. Instruments that meet these hedging criteria are formally designated as hedges at the inception of the derivative contract. To determine the fair values of derivative instruments, we use a variety of methods and assumptions that are based on market conditions and risks existing at each balance sheet date. For the majority of financial instruments including most derivatives, long-term investments and long-term debt, standard market conventions and techniques such as discounted cash flow analysis, option pricing models, replacement cost, and termination cost are used to determine fair value. All methods of assessing fair value result in a general approximation of value, and such value may never actually be realized. In the normal course of business, we are exposed to the effect of interest rate changes and limit these risks by following established risk management policies and procedures including the use of derivatives. To address exposure to interest rates, derivatives are used primarily to fix the rate on debt based on floating-rate indices and manage the cost of borrowing obligations. We use a variety of commonly used derivative products that are considered plain vanilla derivatives. These derivatives typically include interest rate swaps, caps, collars and floors. We expressly prohibit the use of unconventional derivative instruments and using derivative instruments for trading or speculative purposes. Further, we have a policy of only entering into contracts with major financial institutions based upon their credit ratings and other factors. We may employ swaps, forwards or purchased options to hedge qualifying forecasted transactions. Gains and losses related to these transactions are deferred and recognized in net income as interest expense in the same period or periods that the underlying transaction occurs, expires or is otherwise terminated. Hedges that are reported at fair value and presented on the balance sheet could be characterized as cash flow hedges or fair value hedges. Interest rate caps and collars are examples of cash flow hedges. Cash flow hedges address the risk associated with future cash flows of interest payments. For all hedges held by us and which were deemed to be fully effective in meeting the hedging objectives established by our corporate policy governing interest rate risk management, no net gains or losses were reported in earnings. The changes in fair value of hedge instruments are reflected in accumulated other comprehensive income. For derivative instruments not designated as hedging instruments, the gain or loss, resulting from the change in the estimated fair value of the derivative instruments, is recognized in current earnings during the period of change.
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 to eliminate discontinued operations from income from continuing operations.
Accounting Standards Updates	Accounting Standards Updates In January 2016, the FASB issued Accounting Standards Update No. 2016-01 (ASU825-10), Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and to record changes in instruments-specific credit risk for financial liabilities measured under the fair value option in other comprehensive income. The guidance is effective for fiscal years beginning after December 15, 2017, and for interim periods therein. The Company is currently evaluating the impact of adopting this new accounting standard on the Company’s consolidated financial statements. 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. 2015-16). 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 adopted the guidance effective January 1, 2016 and the guidance does not have a material impact 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 changed the presentation of discontinued operations for all properties held for sale and/or disposed of subsequent to January 1, 2015.

Organization and Basis of Pre39

Organization and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of commercial office properties	As of December 31, 2015 , we owned the following interests in 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 Property Type Number of Properties Approximate Square Feet (unaudited) Number of Properties Approximate Square Feet (unaudited) Number of Properties Approximate Square Feet (unaudited) Weighted Average Occupancy (1) (unaudited) Commercial: Manhattan Office 27 21,003,606 5 3,024,981 32 24,028,587 94.2 % Retail 9 (2) 408,993 9 347,970 18 756,963 89.1 % Development/Redevelopment 3 42,635 4 1,952,782 7 1,995,417 59.0 % Fee Interest 2 783,530 — — 2 783,530 100.0 % 41 22,238,764 18 5,325,733 59 27,564,497 91.7 % Suburban Office 26 4,235,300 3 705,641 29 4,940,941 79.0 % Retail 1 52,000 — — 1 52,000 100.0 % Development/Redevelopment 1 1,000 1 — 2 1,000 100.0 % 28 4,288,300 4 705,641 32 4,993,941 79.2 % Total commercial properties 69 26,527,064 22 6,031,374 91 32,558,438 89.8 % Residential: Manhattan Residential 4 (2) 762,587 17 2,193,424 21 2,956,011 94.2 % Suburban Residential 1 (3) 66,611 — — 1 66,611 94.4 % Total residential properties 5 829,198 17 2,193,424 22 3,022,622 94.2 % Total portfolio 74 27,356,262 39 8,224,798 113 35,581,060 90.1 % ____________________________________________________________________ (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) As of December 31, 2015 , we owned a building that was comprised of approximately 270,132 square feet (unaudited) of retail space and approximately 222,855 square feet (unaudited) 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. (3) This property was held for sale as of December 31, 2015 . In February 2016, the property was sold.

Significant Accounting Polici40

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Schedule of estimated useful lives	Properties are depreciated using the straight-line method over the estimated useful lives of the assets. The estimated useful lives are as follows: Category Term Building (fee ownership) 40 years Building improvements shorter of remaining life of the building or useful life Building (leasehold interest) lesser of 40 years or remaining term of the lease Property under capital lease remaining lease term Furniture and fixtures four to seven years Tenant improvements shorter of remaining term of the lease or useful life
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 December 31, 2015 and 2014 (in thousands): December 31, 2015 2014 Identified intangible assets (included in other assets): Gross amount $ 939,518 $ 664,297 Accumulated amortization (403,747 ) (383,236 ) Net (1) $ 535,771 $ 281,061 Identified intangible liabilities (included in deferred revenue): Gross amount $ 866,561 $ 655,755 Accumulated amortization (486,928 ) (483,948 ) Net (1) $ 379,633 $ 171,807 ____________________________________________________________________ (1) As of December 31, 2015, $0.2 million and $0.1 million of net intangible assets and net intangible liabilities, respectively, were reclassified to assets held for sale and liabilities related to assets held for sale.
Schedule of estimated annual amortization of acquired above-market leases, net of acquired below-market leases	The estimated annual amortization of acquired above-market leases, net of acquired (below-market) leases (a component of rental revenue), for each of the five succeeding years is as follows (in thousands): 2016 $ 4,002 2017 2,129 2018 439 2019 (376 ) 2020 (595 )
Schedule of estimated annual amortization of all other identifiable assets	The estimated annual amortization of all other identifiable assets (a component of depreciation and amortization expense) including tenant improvements for each of the five succeeding years is as follows (in thousands): 2016 $ 9,931 2017 8,507 2018 7,207 2019 6,706 2020 6,453
Schedule of marketable securities	At December 31, 2015 and 2014 , we held the following marketable securities (in thousands): December 31, 2015 2014 Equity marketable securities $ 4,704 $ 4,332 Mortgage-backed securities 40,434 35,097 Total marketable securities available-for-sale $ 45,138 $ 39,429
Schedule of Restated Balance Sheets	The accompanying consolidated balance sheet of the Company as of December 31, 2014 and the related statements of equity for the years ended December 31, 2014, 2013, and 2012 have been revised to correct the misclassification as follows (in thousands): As Previously Reported As Adjusted Consolidated balance sheet and consolidated statement of equity as of December 31, 2014: Common shares $ 1,010 $ 974 Additional paid-in capital 5,289,479 5,113,759 Treasury shares (320,471 ) — Retained earnings 1,752,404 1,607,689 Consolidated statement of equity as of December 31, 2013: Common shares $ 986 $ 950 Additional paid-in capital 5,015,904 4,841,800 Treasury shares (317,356 ) — Retained earnings 1,619,150 1,475,934 Consolidated statement of equity as of December 31, 2012: Common shares $ 950 $ 913 Additional paid-in capital 4,667,900 4,490,084 Treasury shares (322,858 ) — Retained earnings 1,701,092 1,556,087
Schedule of Error Corrections and Prior Period Adjustments	The accompanying consolidated balance sheet of the Operating Partnership as of December 31, 2014 and the related statements of capital have been revised to correct the misclassification as follows (amounts in thousands): As Previously Reported As Adjusted Consolidated balance sheet as of December 31, 2014: Mezzanine equity Limited partner interests in SLGOP $ — $ 469,524 Capital SL Green partner's capital 7,078,924 6,722,422 Limited partner interests in SLGOP 113,298 — Partners' Interest Common Units Common Unitholders Balance at December 31, 2012 - as previously reported 91,250 $ 6,189,529 Cumulative Adjustment to carry limited partner interests in mezzanine equity at fair value — (142,445 ) Balance at December 31, 2012 - as adjusted 91,250 $ 6,047,084 Balance at December 31, 2013 - as previously reported 94,993 $ 6,506,747 Cumulative Adjustment to carry limited partner interests in mezzanine equity at fair value — (188,063 ) Balance at December 31, 2013 - as adjusted 94,993 $ 6,318,684 Balance at December 31, 2014 - as previously reported 97,325 $ 7,078,924 Cumulative Adjustment to carry limited partner interests in mezzanine equity at fair value — (356,502 ) Balance at December 31, 2014 - as adjusted 97,325 $ 6,722,422

Property Acquisitions (Tables)

Property Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2015
Property Acquisitions
Schedule of Fair Value of Equity Interest Immediately Before Acquisition Date	The acquisition-date fair value of the equity interest in 600 Lexington Avenue and 388-390 Greenwich Street, which were acquired in 2015 and 2014, respectively, 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, are as follows (in thousands): 600 Lexington Avenue 388-390 Greenwich Street Contract purchase price $ 284,000 $ 1,585,000 Net consideration funded by us at closing, excluding consideration financed by debt (79,085 ) (208,614 ) Debt assumed (112,795 ) (1,162,379 ) Fair value of retained equity interest 92,120 214,007 Equity and/or debt investment held (54,575 ) (148,025 ) Other (1) 2,533 5,464 Purchase price fair value adjustment $ 40,078 $ 71,446 ___________________________________________________________________ (1) Includes the acceleration of a deferred leasing commission from the joint venture to the Company.
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 results of operations for years ended December 31, 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. Year Ended December 31, (in thousands, except per share/unit amounts) 2015 2014 Actual revenues since acquisition $ 29,865 Actual net income since acquisition 159 Pro forma revenues 1,657,937 1,540,525 Pro forma income from continuing operations 102,440 — 376,710 Pro forma basic earnings per share $ 0.76 $ 7.00 Pro forma diluted earnings per share $ 0.75 $ 6.92 Pro forma basic earnings per unit $ 0.76 $ 7.00 Pro forma diluted earnings per unit $ 0.75 $ 6.92 ______________________________________________________________________ (1) The pro forma income from continuing operations for the years ended December 31, 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 year ended December 31, 2014 was adjusted to include the sale of real estate assets for properties that have closed either subsequent to December 31, 2015 or we are currently under contract to sell in connection with 11 Madison Avenue, as if the sales were completed on January 1, 2014. The pro forma net income for the year ended December 31, 2015 excludes these sales.
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): 600 Lexington Avenue (1)(2) 187 Broadway and 5 & 7 Dey Street (1)(3) 11 Madison Avenue (1)(4) 110 Greene Street (1)(5) Upper East Side Residential (1)(6) 1640 Flatbush Avenue (1) Acquisition Date December 2015 August 2015 August 2015 July 2015 June 2015 March 2015 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Fee Interest Property Type Office Residential/Retail Office Office Residential/Retail Retail Purchase Price Allocation: Land $ 97,044 $ 22,101 $ 849,926 $ 89,250 $ 17,500 $ 6,120 Building and building leasehold 180,224 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 277,268 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 $ 277,268 $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Net consideration funded by us at closing, excluding consideration financed by debt $ 79,085 $ 63,146 $ 2,429,044 $ 255,000 $ 50,000 $ 6,800 Equity and/or debt investment held $ 54,575 $ — $ — $ — $ — $ — Debt assumed $ 112,795 $ — $ — $ — $ — $ — ____________________________________________________________________ (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) In December 2015, we acquired Canada Pension Plan Investment Board's 45% interest in this property, thereby consolidating full ownership of the property. The transaction valued the consolidated interests at $277.3 million . We recognized a purchase price fair value adjustment of $40.1 million upon closing of this transaction. This property, which we initially acquired in May 2010, was previously accounted for as an investment in unconsolidated joint ventures. (3) 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. (4) In August 2015, we acquired this property from a partnership of the Sapir Organization and CIM Group, with whom we have no other relationship. (5) 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. (6) 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 year ended December 31, 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 statements of operations for the twelve months ended December 31, 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.
2013 Acquisitions
Property Acquisitions
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	During the year ended December 31, 2013, the properties listed below were acquired from third parties. The following summarizes our allocation of the purchase price of the assets acquired and liabilities assumed upon the closing of these acquisitions (in thousands): 315 West 33rd Street (1) Assemblage of Retail Development Properties on Fifth Avenue (1) 16 Court (2) 248-252 Bedford Avenue (3) Acquisition Date November 2013 November 2013 April 2013 March 2013 Ownership Type Fee Interest Fee Interest Fee Interest Fee Interest Property Type Residential Development Office Residential Purchase Price Allocation: Land $ 195,834 $ 135,513 $ 19,217 $ 10,865 Building and building leasehold 164,429 10,487 63,210 44,035 Above market lease value 7,084 — 5,122 — Acquired in-place leases 26,125 — 9,422 — Other assets, net of other liabilities 1,142 — 3,380 — Assets acquired 394,614 146,000 100,351 54,900 Mark-to-market assumed debt — — 294 — Below market lease value 7,839 — 3,885 — Liabilities assumed 7,839 — 4,179 — Purchase price $ 386,775 $ 146,000 $ 96,172 $ 54,900 Net consideration funded by us at closing, excluding consideration financed by debt $ 386,775 $ 146,000 $ 4,000 $ 21,782 Equity and/or debt investment held $ — $ — $ 13,835 $ — Debt assumed $ — $ — $ 84,642 $ — ____________________________________________________________________ (1) During the year ended December 31, 2014, we finalized the purchase price allocation based on a third party appraisal and additional facts and circumstances that existed at the acquisition dates. These adjustments did not have a material impact to our consolidated statements of operations for the year ended December 31, 2014. (2) In April 2013, we acquired interests from our joint venture partner, City Investment Fund, or CIF, in 16 Court Street in Brooklyn for $4.0 million . We have consolidated the ownership of the building. The transaction valued the consolidated interest at $96.2 million , inclusive of the $84.6 million mortgage encumbering the property. In April 2014, we repaid the mortgage. We recognized a purchase price fair value adjustment of $(2.3) million upon the closing of this transaction. This property, which we initially acquired in July 2007, was previously accounted for as an investment in unconsolidated joint ventures. (3) In March 2013, we, along with Magnum Real Estate Group, acquired 84 residential units, consisting of 72 apartment units and 12 townhouses, located at 248-252 Bedford Avenue, Williamsburg, Brooklyn for $54.9 million . Simultaneous with the closing on this property, the joint venture closed on a $22.0 million mortgage loan which was later refinanced in June 2014. The property is above a commercial property already owned by us. We hold a 90.0% controlling interest in this joint venture.

Properties Held for Sale and 42

Properties Held for Sale and Property Dispositions (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Summary of properties sold and income from discontinued operations	The following table summarizes net income from discontinued operations for the years ended December 31, 2015 , 2014 , and 2013 respectively (in thousands): Year Ended December 31, 2015 2014 2013 Revenues Rental revenue $ 236 $ 51,090 $ 94,558 Escalation and reimbursement revenues (127 ) 4,646 14,856 Other income — 23 554 Total revenues 109 55,759 109,968 Operating expenses (631 ) 7,772 20,568 Real estate taxes 250 7,156 16,521 Ground rent — 3,001 7,975 Transaction related costs (49 ) 89 2 Depreciable real estate reserves — — 2,150 Interest expense, net of interest income 109 12,652 19,782 Amortization of deferred financing costs 3 433 840 Depreciation and amortization — 5,581 16,443 Total expenses (318 ) 36,684 84,281 Net income from discontinued operations $ 427 $ 19,075 $ 25,687 The following table summarizes the properties sold during the years ended December 31, 2015 , 2014 , and 2013 : Property Disposition Date Property Type Approximate Usable Square Feet Sales Price (1) (in millions) Gain (Loss) on Sale (2) (in millions) 140-150 Grand Street (3) December 2015 Office/Development 215,100 $ 32.0 $ (20.1 ) 570 & 574 Fifth Avenue December 2015 Development 24,327 125.4 24.6 120 West 45th Street September 2015 Office 440,000 365.0 58.6 131-137 Spring Street (4) August 2015 Office 68,342 277.8 101.1 180 Maiden Lane January 2015 Office 1,090,000 470.0 17.0 2 Herald Square November 2014 Land 354,400 365.0 18.8 985-987 Third Avenue July 2014 Development 13,678 68.7 29.8 673 First Avenue May 2014 Office 422,000 145.0 117.6 300 Main Street September 2013 Office 130,000 13.5 (2.2 ) 333 West 34th Street August 2013 Office 345,400 220.3 13.8 44 West 55th Street February 2013 Retail 8,557 6.3 1.1 ____________________________________________________________________ (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 570 & 574 Fifth Avenue, 120 West 45th Street, 131-137 Spring Street, 180 Maiden Lane, 2 Herald Square, 985-987 Third Avenue, 673 First Avenue and 333 West 34th Street are net of $4.0 million , $2.0 million , $4.1 million , $0.8 million , $2.5 million , $1.3 million , $3.4 million and $3.0 million in 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) Gain/(loss) on sale includes a $19.2 million charge that was recorded during the third quarter of 2015. This charge is included in depreciable real estate reserves in the consolidated statement of operations. (4) 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."

Debt and Preferred Equity Inv43

Debt and Preferred Equity Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of debt investments	As of December 31, 2015 and 2014, we held the following debt investments with an aggregate weighted average current yield of 10.23% at December 31, 2015 (in thousands): Loan Type December 31, 2015 Future Funding Obligations December 31, 2015 Senior Financing December 31, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Fixed Rate Investments: Jr. Mortgage Participation/ Mezzanine Loan (2)(3) $ — $ — $ 23,510 $ 45,611 May 2016 Jr. Mortgage Participation — 133,000 49,000 49,000 June 2016 Mezzanine Loan — 115,000 24,916 24,910 July 2016 Mezzanine Loan — 165,000 72,102 71,656 November 2016 Jr. Mortgage Participation/Mezzanine Loan — 1,109,000 104,661 98,934 March 2017 Mezzanine Loan (3) — — 66,183 65,770 March 2017 Mezzanine Loan (4) — 502,100 41,115 24,608 June 2017 Mezzanine Loan — 539,000 49,691 49,629 July 2018 Mortgage Loan (5) — — 26,262 26,209 February 2019 Mortgage Loan — — 513 637 August 2019 Mezzanine Loan — 15,000 3,500 3,500 September 2021 Mezzanine Loan (6) — 89,880 19,936 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 Jr. Mortgage Participation (9) — — — 70,688 Total fixed rate $ — $ 2,762,980 $ 511,389 $ 607,084 Floating Rate Investments: Mezzanine Loan — 775,000 74,700 73,402 March 2016 Mortgage/Mezzanine Loan 10,156 — 94,901 — April 2016 Mezzanine Loan (10) — 160,000 22,625 22,573 June 2016 Mezzanine Loan 7,942 312,939 66,398 — November 2016 Mezzanine Loan — 360,000 99,530 99,023 November 2016 Mezzanine Loan (11) 11,414 131,939 49,751 42,750 December 2016 Mezzanine Loan 281 39,201 13,731 11,835 December 2016 Mortgage/Mezzanine Loan (12) 57,108 — 134,264 — January 2017 Mezzanine Loan 1,293 118,949 28,551 20,651 January 2017 Mortgage/Mezzanine Loan — — 68,977 — June 2017 Jr. Mortgage Participation/Mezzanine Loan 1,257 118,717 40,346 38,524 July 2017 Loan Type December 31, 2015 Future Funding Obligations December 31, 2015 Senior Financing December 31, 2015 Carrying Value (1) December 31, 2014 Carrying Value (1) Initial Maturity Date Mortgage/Mezzanine Loan — — 22,877 22,803 July 2017 Mortgage/Mezzanine Loan — — 16,901 16,848 September 2017 Mortgage/Mezzanine Loan 4,500 — 19,282 — October 2017 Mezzanine Loan — 60,000 14,904 14,859 November 2017 Mezzanine Loan — 85,000 29,505 — December 2017 Mezzanine Loan — 65,000 28,563 — December 2017 Mortgage/Mezzanine Loan (13) 795 — 14,942 14,845 December 2017 Jr. Mortgage Participation — 40,000 19,846 — April 2018 Mezzanine Loan — 175,000 34,725 — April 2018 Jr. Mortgage Participation/Mezzanine Loan — 55,000 20,510 20,533 July 2018 Mortgage/Mezzanine Loan (14) 1,500 — 31,210 — August 2018 Mezzanine Loan — 33,000 26,777 December 2018 Mezzanine Loan 6,383 156,383 52,774 — December 2018 Mezzanine Loan 28,801 206,717 49,625 — December 2018 Mortgage/Mezzanine Loan — — 18,395 18,083 February 2019 Mezzanine Loan — 38,000 21,845 21,807 March 2019 Mezzanine Loan (15) — — — 33,726 Mezzanine Loan (15) — — — 37,322 Mortgage/Mezzanine Loan (16) — — — 109,527 Mezzanine Loan (17) — — — 49,614 Total floating rate $ 131,430 $ 2,930,845 $ 1,116,455 $ 668,725 Total $ 131,430 $ 5,693,825 $ 1,627,844 $ 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) These loans were repaid in December 2015. (10) 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. (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) In January 2016, the loans were modified and the mortgage was sold. (15) These loans were repaid in April 2015. (16) This loan was repaid in August 2015. (17) This loan was repaid in November 2015.
Summary of preferred equity investments	As of December 31, 2015 and 2014 , we held the following preferred equity investments with an aggregate weighted average current yield of 7.86% at December 31, 2015 (in thousands): Type December 31, 2015 Future Funding Obligations December 31, 2015 Senior Financing December 31, 2015 Carrying Value (1) December 31, 2014 (1) Initial Mandatory Redemption Preferred equity (2) $ — $ 71,486 $ 9,967 $ 9,954 March 2018 Preferred equity 5,580 60,183 32,209 — November 2018 Preferred equity (3) — — — 123,041 $ 5,580 $ 131,669 $ 42,176 $ 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.
Rollforward of total allowance for loan loss reserves	The following table is a rollforward of our total loan loss reserves at December 31, 2015 , 2014 and 2013 (in thousands): December 31, 2015 2014 2013 Balance at beginning of year $ — $ 1,000 $ 7,000 Expensed — — — Recoveries — — — Charge-offs and reclassifications — (1,000 ) (6,000 ) Balance at end of period $ — $ — $ 1,000

Investments in Unconsolidated44

Investments in Unconsolidated Joint Ventures (Tables)	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Schedule of general information on joint ventures	The table below provides general information on each of our joint ventures as of December 31, 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 (3) Onyx Equities/Credit Suisse 77.78% 77.78% 640,000 April 2007 210,000 11 West 34th Street Private Investor/ Jeff Sutton 30.00% 30.00% 17,150 December 2010 10,800 7 Renaissance (4) Louis Cappelli 50.00% 50.00% 65,641 December 2010 4,000 3 Columbus Circle (5) 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 (6) 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 (7) 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 (8) Private Investors 32.28% 32.28% 16,736 December 2012 75,000 650 Fifth Avenue (9) 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 (10) Various Various Various 2,046,733 February 2015 36,668 131-137 Spring Street (11) 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) In connection with the restructuring of the joint venture and the loan on the property, our ownership increased by 57.52% in October 2015. Our ownership percentage was reduced in the first quarter of 2016 upon completion of the restructuring in the first quarter of 2016. (4) Subsequent to December 31, 2015, we entered into a contract to sell 7 Renaissance for a gross sales price of $20.7 million . The sale is anticipated to close in March 2016, subject to customary closing conditions. (5) 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. (6) 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. (7) 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. (8) 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. (9) 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. (10) 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 . (11) In August 2015, we sold an 80% interest in 131-137 Spring Street. These properties, which were previously wholly-owned, were accounted for in commercial real estate properties on 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 years ended December 31, 2015 , 2014 , and 2013 : 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 (3) 35.50% September 2015 Ownership Interest 115.0 16.3 180 Broadway (4) 25.50% September 2014 Property 222.5 16.5 747 Madison Avenue (5) 33.33% May 2014 Ownership Interest 160.0 — West Coast Office portfolio (6) 42.02% March 2014 Ownership Interest 756.0 85.6 21-25 West 34th Street (7) 49.90% January 2014 Ownership Interest 114.9 20.9 27-29 West 34th Street (8) 50.00% December 2013 Ownership Interest 70.1 7.6 West Coast Office Portfolio (6) 42.04% Various dates in 2013 Property 224.3 2.1 ___________________________________________________________________ (1) Represents implied gross valuation for the joint venture or sales price of the property. (2) Represents the Company's share of the gain or loss. (3) The gain on sale for 315 West 36th Street is net of $1.2 million 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. (4) In connection with the sale of the property, we also recognized a promote of $3.3 million . (5) We sold our ownership interest in the joint venture, which owns 100% interest as tenant-in-common in 30 East 65th Street Corporation and the related proprietary lease of five cooperative apartment units in the property. We also recognized a promote of $10.3 million and originated a $30.0 million preferred equity investment. Given our continuing involvement as a preferred equity holder, we deferred the gain on sale of $13.1 million as we did not meet the requirements of a sale under the full accrual method. We, along with our joint venture partners, retained one apartment unit at this property. (6) During the year ended December 31, 2013, the joint venture sold three properties, the proceeds of which were used primarily to repay a portion of the debt. Also during the year ended December 31, 2013, we acquired in aggregate 14.39% ownership interest of two of our joint venture partners. As a result, we had a 42.04% effective ownership interest ( 43.74% effective economic interest) in the West Coast portfolio as of December 31, 2013. During the year ended December 31, 2014, we sold our ownership interest in the joint venture. (7) We sold our ownership interest in the joint venture. We, along with our joint venture partner, retained approximately 91,300 square feet (unaudited) of development rights at the property. (8) We sold our ownership interest in the joint venture. The gain on the sale is net of a $1.5 million employee compensation award, accrued in connection with the realization of this investment gain as a bonus to certain employees that were instrumental in realizing the gain on this sale. Simultaneously, we, along with Sutton, also formed a new joint venture and retained the air rights at this property. As of December 31, 2015 and 2014, the carrying value for acquisition, development and construction arrangements were as follows (in thousands): Loan Type December 31, 2015 December 31, 2014 Initial Maturity Date Mezzanine loan and preferred equity $ 99,936 $ 99,629 March 2016 Mezzanine loan (1) 45,942 46,246 February 2022 $ 145,878 $ 145,875 ____________________________________________________________________ (1) We have an option to convert our loan to an equity interest subject to certain conditions. We have determined that our option to convert the loan to equity is not a derivative financial instrument pursuant to GAAP.
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 December 31, 2015 and 2014 , respectively, are as follows (amounts in thousands): Property Maturity Date Interest Rate (1) December 31, 2015 December 31, 2014 Fixed Rate Debt: 280 Park Avenue June 2016 6.57 % $ 692,963 $ 700,171 7 Renaissance December 2016 10.00 % 2,927 2,147 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 % 170,000 170,000 717 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 % 325,704 314,381 3 Columbus Circle (4) March 2025 3.45 % 350,000 — Stonehenge Portfolio (5) Various 4.18 % 430,627 — 315 West 36th Street (6) — 25,000 11 West 34th Street — 16,905 Total fixed rate debt $ 2,808,881 $ 2,065,264 Floating Rate Debt: 1552 Broadway (7) April 2016 4.35 % 190,409 184,210 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 4.26 % 40,000 40,000 10 East 53rd Street February 2017 2.70 % 125,000 125,000 724 Fifth Avenue April 2017 2.61 % 275,000 275,000 33 Beekman (9) August 2017 2.94 % 73,518 52,283 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 11 West 34th Street (11) January 2021 4.57 % 23,000 — 100 Park Avenue February 2021 1.95 % 360,000 360,000 131-137 Spring Street August 2020 1.76 % 141,000 — 21 East 66th Street June 2033 2.97 % 1,805 1,883 3 Columbus Circle (4) — 230,974 The Meadows (12) — 67,350 600 Lexington Avenue (13) — 116,740 Total floating rate debt $ 1,500,232 $ 1,713,440 Total joint venture mortgages and other loans payable $ 4,309,113 $ 3,778,704 ____________________________________________________________________ (1) Effective weighted average interest rate for the year ended December 31, 2015 , taking into account interest rate hedges in effect during the period. (2) As of December 31, 2015, we were in the process of restructuring the joint venture, which would reduce our ownership interest, and the loan on the Property. Subsequent to December 31, 2015, we along with our joint venture partners closed on the restructuring and refinancing. We hold an 11.67% non-controlling interest in the joint venture and the property secures a two year $100.0 million floating rate loan, of which $75.0 million is currently outstanding. (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 $13.3 million , $55.5 million , $35.0 million , $7.3 million , $141.5 million , and $177.9 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 December 31, 2015 , $0.6 million of the mortgage loan and $0.5 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 December 31, 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. The sale of this property is currently under contract, and the sale is expected to be completed in the first half of 2016. (10) This loan has a committed amount of $190.0 million , of which $40.0 million was unfunded as of December 31, 2015 . (11) In December 2015, the joint venture refinanced the previous mortgage. (12) In August 2015, these properties were sold and the debt was repaid. (13) In December 2015, we acquired our joint venture partner's interest in 600 Lexington Avenue thereby assuming full ownership, and accounting for the property on a consolidated basis.
Schedule of combined balance sheets for the unconsolidated joint ventures	The combined balance sheets for the unconsolidated joint ventures, at December 31, 2015 and 2014, are as follows (in thousands): December 31, 2015 December 31, 2014 Assets Commercial real estate property, net $ 6,122,468 $ 5,275,632 Other assets 904,283 810,567 Total assets $ 7,026,751 $ 6,086,199 Liabilities and members' equity Mortgages and other loans payable $ 4,309,113 $ 3,778,704 Other liabilities 523,160 485,572 Members' equity 2,194,478 1,821,923 Total liabilities and members' equity $ 7,026,751 $ 6,086,199 Company's investments in unconsolidated joint ventures $ 1,203,858 $ 1,172,020
Schedule of combined statements of income for the unconsolidated joint ventures	The combined statements of operations for the unconsolidated joint ventures, from acquisition date through the years ended December 31, 2015 , 2014 , and 2013 are as follows (in thousands): Year Ended December 31, 2015 2014 2013 Total revenues $ 576,845 $ 522,132 $ 628,649 Operating expenses 106,613 82,436 114,633 Ground rent 14,083 9,898 2,863 Real estate taxes 89,734 64,217 71,755 Interest expense, net of interest income 199,126 178,743 225,765 Amortization of deferred financing costs 13,394 12,395 17,092 Transaction related costs 615 535 808 Depreciation and amortization 149,023 137,793 192,504 Total expenses 572,588 486,017 625,420 Loss on early extinguishment of debt (1,089 ) (6,743 ) — Net income before gain on sale $ 3,168 $ 29,372 $ 3,229 Company's equity in net income from unconsolidated joint ventures $ 13,028 $ 26,537 $ 9,921

Deferred Costs (Tables)

Deferred Costs (Tables)	12 Months Ended
	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of components of deferred costs	Deferred costs at December 31, 2015 and 2014 consisted of the following (in thousands): December 31, 2015 2014 Deferred leasing $ 415,406 $ 385,555 Deferred financing 241,775 193,776 657,181 579,331 Less accumulated amortization (286,746 ) (251,369 ) Deferred costs, net $ 370,435 $ 327,962

Mortgages and Other Loans Pay46

Mortgages and Other Loans Payable (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 , respectively, were as follows (amounts in thousands): Property Maturity Date Interest Rate (1) December 31, 2015 December 31, 2014 Fixed Rate Debt: 500 West Putnam Avenue (2) January 2016 5.52 % 22,376 22,968 Landmark Square December 2016 4.00 % 79,562 81,269 485 Lexington Avenue February 2017 5.61 % 450,000 450,000 762 Madison Avenue (3) February 2017 3.84 % 7,872 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 % 542,817 565,742 100 Church Street July 2022 4.68 % 225,099 228,612 919 Third Avenue (5) June 2023 5.12 % 500,000 500,000 400 East 57th Street February 2024 4.13 % 67,644 68,896 400 East 58th Street February 2024 4.13 % 28,990 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 $ 5,816,010 $ 4,736,709 Floating Rate Debt: Master Repurchase Agreement June 2016 3.36 % 253,424 100,000 FHLB Facility (9) Various Various 45,750 — 600 Lexington Avenue October 2017 2.30 % 112,795 — 187 Broadway & 5-7 Dey Street October 2017 2.85 % 40,000 — 388-390 Greenwich Street (4) June 2018 1.94 % 446,000 446,000 1080 Amsterdam November 2018 3.96 % 3,525 — 248-252 Bedford Avenue (10) June 2019 1.69 % 29,000 29,000 220 East 42nd Street October 2020 1.80 % 275,000 275,000 180 Maiden Lane (11) — 253,942 Total floating rate debt $ 1,205,494 $ 1,103,942 Total fixed rate and floating rate debt $ 7,021,504 $ 5,840,651 Mortgages reclassed to liabilities related to assets held for sale (29,000 ) (253,942 ) Total mortgages and other loans payable $ 6,992,504 $ 5,586,709 ____________________________________________________________________ (1) Effective weighted average interest rate for the year ended December 31, 2015 , taking into account interest rate hedges in effect during the period. (2) In January 2016, the mortgage was repaid. (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 in May 2014, 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 consolidated 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 , 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, the mortgage was repaid. (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) The FHLB Facility is comprised of four distinct advances of $1.0 million , $15.8 million , $5.0 million , and $24.0 million that mature in April 2016, April 2016, June 2016 and December 2016, respectively. The weighted average interest rates on these advances range from 0.50% to 0.58% . (10) This property was held for sale at December 31, 2015 and the related mortgage is included in liabilities related to assets held for sale. In February 2016, the property was sold and the debt was repaid. (11) 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)	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 , respectively, by scheduled maturity date (dollars in thousands): Issuance December 31, 2015 Unpaid Principal Balance December 31, 2015 Accreted Balance December 31, 2014 Accreted Balance Coupon Rate (1) Effective Rate Term (in Years) Maturity Date March 31, 2006 (2)(3) $ 255,308 $ 255,296 $ 255,250 6.00 % 6.00 % 10 March 31, 2016 October 12, 2010 (4) 345,000 321,130 309,069 3.00 % 3.00 % 7 October 15, 2017 August 5, 2011 (5) 250,000 249,810 249,744 5.00 % 5.00 % 7 August 15, 2018 March 16, 2010 (5) 250,000 250,000 250,000 7.75 % 7.75 % 10 March 15, 2020 November 15, 2012 (5) 200,000 200,000 200,000 4.50 % 4.50 % 10 December 1, 2022 December 17, 2015 (5) 100,000 100,000 — 4.27 % 4.27 % 10 December 17, 2025 March 26, 2007 (6) 10,008 10,008 10,008 3.00 % 3.00 % 20 March 30, 2027 June 27, 2005 (2)(7) — — 7 $ 1,410,316 $ 1,386,244 $ 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) The notes will be repaid at maturity. (4) 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 12.3416 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, 2016 and will remain exchangeable through March 31, 2016. The notes are guaranteed by ROP. On the issuance date, $78.3 million of the debt balance was recorded in equity. As of December 31, 2015 , $23.9 million remained to be amortized into the debt balance. (5) Issued by the Company, the Operating Partnership and ROP, as co-obligors. (6) 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. (7) 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 December 31, 2015 , including as-of-right extension options and put options, were as follows (in thousands): Scheduled Amortization Principal Revolving Credit Facility Unsecured Term Loan Trust Preferred Securities Senior Unsecured Notes Total Joint Venture Debt 2016 $ 51,018 $ 399,486 $ — $ — $ — $ 255,308 $ 705,812 $ 529,646 2017 63,829 871,548 — — — 355,008 1,290,385 615,085 2018 64,462 19,525 — — — 250,000 333,987 2,195 2019 70,409 28,317 — 933,000 — — 1,031,726 104,687 2020 52,799 679,531 994,000 — — 250,000 1,976,330 30,298 Thereafter 147,604 4,572,974 — — 100,000 300,000 5,120,578 451,544 $ 450,121 $ 6,571,381 $ 994,000 $ 933,000 $ 100,000 $ 1,410,316 $ 10,458,818 $ 1,733,455
Schedule of consolidated interest expense, excluding capitalized interest	Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Year Ended December 31, 2015 2014 2013 Interest expense $ 326,818 $ 319,898 $ 312,897 Interest income (2,948 ) (2,498 ) (2,003 ) Interest expense, net $ 323,870 $ 317,400 $ 310,894 Interest capitalized $ 31,108 $ 22,750 $ 11,475

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Schedule of amounts due from/to related parties	Amounts due from related parties at December 31, 2015 and 2014 consisted of the following (in thousands): December 31, 2015 2014 Due from joint ventures $ 1,334 $ 1,254 Other 9,316 10,481 Related party receivables $ 10,650 $ 11,735

Noncontrolling Interests on t49

Noncontrolling Interests on the Company's Consolidated Financial Statements (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 2014 Balance at beginning of period $ 469,524 $ 265,476 Distributions (9,710 ) (7,849 ) Issuance of common units 30,506 56,469 Redemption of common units (55,697 ) (31,653 ) Net income 10,565 18,467 Accumulated other comprehensive income allocation (67 ) 175 Fair value adjustment (20,915 ) 168,439 Balance at end of period $ 424,206 $ 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 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 C50

Stockholders' Equity of the Company (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Schedule of Common Stock Issued and Proceeds Received Dividend Reinvestments	The following table summarizes SL Green common stock issued, and proceeds received from dividend reinvestments and/or stock purchases under the DRSPP for the year ended December 31, 2015, 2014, and 2013, respectively (in thousands): Year Ended December 31, 2015 2014 2013 Common Stock Shares Issued 775,760 608 761 Dividend reinvestments/stock purchases under the DRSPP $ 99,555 $ 64 $ 67
Schedule of Earnings Per Share	SL Green's earnings per share for the years ended December 31, 2015 , 2014 , and 2013 are computed as follows (in thousands): Year Ended December 31, Numerator 2015 2014 2013 Basic Earnings: Income attributable to SL Green common stockholders $ 269,132 $ 503,104 $ 101,330 Effect of Dilutive Securities: Redemption of units to common shares 10,565 18,467 3,023 Diluted Earnings: Income attributable to SL Green common stockholders $ 279,697 $ 521,571 $ 104,353 Year Ended December 31, Denominator 2015 2014 2013 Basic Shares: Weighted average common stock outstanding 99,345 95,774 92,269 Effect of Dilutive Securities: Redemption of units to common shares 3,899 3,514 2,735 Stock-based compensation plans 490 408 262 Diluted weighted average common stock outstanding 103,734 99,696 95,266

Partners' Capital of the Oper51

Partners' Capital of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of calculation of numerator and denominator in earnings per unit	The Operating Partnership's earnings per unit for the years ended December 31, 2015 , 2014 , and 2013 respectively are computed as follows (in thousands): Year Ended December 31, Numerator 2015 2014 2013 Basic and Diluted Earnings: Income attributable to SLGOP common unitholders $ 279,697 $ 521,571 $ 104,353 Year Ended December 31, Denominator 2015 2014 2013 Basic units: Weighted average common units outstanding 103,244 99,288 95,004 Effect of Dilutive Securities: Stock-based compensation plans 490 408 262 Diluted weighted average common units outstanding 103,734 99,696 95,266

Share-based Compensation (Table

Share-based Compensation (Tables)	12 Months Ended
	Dec. 31, 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 years ended December 31, 2015 , 2014 , and 2013 . 2015 2014 2013 Dividend yield 1.97 % 1.60 % 1.92 % Expected life of option 3.6 years 3.6 years 4.1 years Risk-free interest rate 1.43 % 1.29 % 0.96 % Expected stock price volatility 32.34 % 33.97 % 36.12 %
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 December 31, 2015 , 2014 , and 2013 and changes during the years ended December 31, 2015 , 2014 , and 2013 are as follows: 2015 2014 2013 Options Outstanding Weighted Average Exercise Price Options Outstanding Weighted Average Exercise Price Options Weighted Balance at beginning of year $ 1,462,726 $ 87.98 $ 1,765,034 $ 83.24 $ 1,201,000 $ 75.05 Granted 389,836 112.54 102,050 119.12 828,100 87.23 Exercised (217,438 ) 74.69 (348,156 ) 72.76 (223,531 ) 53.93 Lapsed or cancelled (40,117 ) 98.61 (56,202 ) 90.03 (40,535 ) 83.94 Balance at end of year $ 1,595,007 $ 95.52 $ 1,462,726 $ 87.98 $ 1,765,034 $ 83.24 Options exercisable at end of year 589,055 $ 89.85 428,951 $ 90.32 $ 461,458 $ 89.38 Weighted average fair value of options granted during the year $ 9,522,613 $ 2,841,678 $ 18,041,576
Summary of restricted stock and charges during the period	A summary of the Company's restricted stock as of December 31, 2015 , 2014 , and 2013 and charges during the years ended December 31, 2015 , 2014 , and 2013 are as follows: 2015 2014 2013 Balance at beginning of year 3,000,979 2,994,197 2,804,901 Granted 143,053 9,550 192,563 Cancelled (6,151 ) (2,768 ) (3,267 ) Balance at end of year 3,137,881 3,000,979 2,994,197 Vested during the year 87,081 75,043 21,074 Compensation expense recorded $ 7,540,747 $ 9,658,019 $ 6,713,155 Weighted average fair value of restricted stock granted during the year $ 16,061,201 $ 1,141,675 $ 17,386,949

Accumulated Other Comprehensi53

Accumulated Other Comprehensive Loss(Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2015 , 2014 and 2013 (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, 2012 $ (16,834 ) $ (16,063 ) $ 3,310 $ (29,587 ) Other comprehensive (loss) income before reclassifications (168 ) 6,267 1,474 7,573 Amounts reclassified from accumulated other comprehensive income 1,877 4,926 — 6,803 Balance at December 31, 2013 (15,125 ) (4,870 ) 4,784 (15,211 ) Other comprehensive (loss) income before reclassifications (576 ) 2,847 (2,692 ) (421 ) Amounts reclassified from accumulated other comprehensive income 6,203 1,928 521 8,652 Balance at December 31, 2014 (9,498 ) (95 ) 2,613 (6,980 ) Other comprehensive loss before reclassifications (11,143 ) (1,714 ) (610 ) (13,467 ) Amounts reclassified from accumulated other comprehensive income 10,481 1,217 — 11,698 Balance at December 31, 2015 $ (10,160 ) $ (592 ) $ 2,003 $ (8,749 ) ____________________________________________________________________ (1) Amount reclassified from accumulated other comprehensive income (loss) is included in interest expense in the respective consolidated statements of operations. As of December 31, 2015 and 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 $9.7 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.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2015 and 2014 (in thousands): December 31, 2015 Total Level 1 Level 2 Level 3 Assets: Marketable securities $ 45,138 $ 4,704 $ 40,434 $ — Interest rate cap and swap agreements (included in other assets) $ 204 $ — $ 204 $ — Liabilities: Interest rate cap swap agreements (included in accrued interest payable and other liabilities) $ 10,776 $ — $ 10,776 $ — 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 December 31, 2015 and December 31, 2014 (in thousands): December 31, 2015 December 31, 2014 Carrying Value Fair Value Carrying Value Fair Value Debt and preferred equity investments $ 1,670,020 (1) $ 1,408,804 (1) Fixed rate debt $ 7,232,254 $ 7,591,388 $ 6,140,786 $ 6,565,236 Variable rate debt (2) 3,202,494 3,179,186 2,291,943 2,315,952 $ 10,434,748 $ 10,770,574 $ 8,432,729 $ 8,881,188 ____________________________________________________________________ (1) At December 31, 2015 , debt and preferred equity investments had an estimated fair value ranging between $1.7 billion and $1.8 billion . At December 31, 2014, debt and preferred equity investments had an estimated fair value ranging between $1.5 billion and $1.8 billion . (2) Includes the $29.0 million mortgage at 248-252 Bedford Avenue that is included in liabilities related to assets held for sale on the consolidated balance sheets at December 31, 2015. Includes the $253.9 million mortgage at 180 Maiden Lane that is included in liabilities related to assets held for sale on the consolidated balance sheets at December 31, 2014.

Financial Instruments_ Deriva55

Financial Instruments: Derivatives and Hedging (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 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 Assets — Interest Rate Cap - Sold 500,000 4.750 % November 2014 May 2016 Other Liabilities — Interest Rate Cap 446,000 4.750 % October 2014 May 2016 Other Assets — Interest Rate Swap 200,000 0.938 % October 2014 December 2017 Other Assets 71 Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Assets 47 Interest Rate Swap 150,000 0.940 % October 2014 December 2017 Other Assets 47 Interest Rate Swap 144,000 2.236 % December 2012 December 2017 Other Liabilities (3,516 ) Interest Rate Swap 86,400 1.948 % December 2012 December 2017 Other Liabilities (1,630 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (1,862 ) Interest Rate Swap 72,000 1.345 % December 2012 December 2017 Other Liabilities (522 ) Interest Rate Swap 72,000 2.310 % December 2012 December 2017 Other Liabilities (1,859 ) Interest Rate Swap 57,600 1.990 % December 2012 December 2017 Other Liabilities (1,134 ) Interest Rate Swap 30,000 2.295 % July 2010 June 2016 Other Liabilities (241 ) Interest Rate Swap 14,409 0.500 % January 2015 January 2017 Other Assets 36 Interest Rate Swap 8,018 0.852 % February 2015 February 2017 Other Liabilities (12 ) Interest Rate Cap 137,500 4.000 % September 2015 September 2017 Other Assets 3 $ (10,572 )
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 years ended December 31, 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) Year Ended Year Ended Year Ended Derivative 2015 2014 2013 2015 2014 2013 2015 2014 2013 Interest Rate Swaps/Caps $ (11,607 ) $ (703 ) $ (68 ) Interest expense $ 10,892 $ 6,431 $ 1,933 Interest expense $ (422 ) $ 4 $ 3 Share of unconsolidated joint ventures' derivative instruments (1,779 ) 2,916 6,553 Equity in net income from unconsolidated joint ventures 1,265 1,999 5,072 Equity in net income from unconsolidated joint ventures (19 ) — — $ (13,386 ) $ 2,213 $ 6,485 $ 12,157 $ 8,430 $ 7,005 $ (441 ) $ 4 $ 3

Rental Income (Tables)

Rental Income (Tables)	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Schedule of approximate future minimum rents to be received over the next five years and thereafter	Approximate future minimum rents to be received over the next five years and thereafter for non-cancelable operating leases in effect at December 31, 2015 for the consolidated properties, including consolidated joint venture properties, and our share of unconsolidated joint venture properties are as follows (in thousands): Consolidated Properties Unconsolidated Properties 2016 $ 1,181,279 $ 175,027 2017 1,162,046 181,804 2018 1,087,356 177,630 2019 996,282 167,695 2020 940,948 158,575 Thereafter 6,780,451 958,010 $ 12,148,362 $ 1,818,741

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Schedule of contributions made to multi-employer plans	Contributions we made to the multi-employer plans for the years ended December 31, 2015 , 2014 and 2013 are included in the table below (in thousands): Benefit Plan 2015 2014 2013 Pension Plan $ 2,732 $ 2,807 $ 2,765 Health Plan 8,736 8,470 8,522 Other plans 5,716 5,838 6,006 Total plan contributions $ 17,184 $ 17,115 $ 17,293

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2015 (in thousands): Capital lease Non-cancellable operating leases 2016 $ 2,266 $ 30,816 2017 2,387 31,049 2018 2,387 31,049 2019 2,411 31,066 2020 2,620 31,436 Thereafter 825,483 764,352 Total minimum lease payments 837,554 $ 919,768 Less amount representing interest (796,194 ) Capital lease obligations $ 41,360
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 December 31, 2015 (in thousands): Capital lease Non-cancellable operating leases 2016 $ 2,266 $ 30,816 2017 2,387 31,049 2018 2,387 31,049 2019 2,411 31,066 2020 2,620 31,436 Thereafter 825,483 764,352 Total minimum lease payments 837,554 $ 919,768 Less amount representing interest (796,194 ) Capital lease obligations $ 41,360

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Schedule of selected results of operations and selected asset information	Selected results of operations for the years ended December 31, 2015 , 2014 , and 2013 , and selected asset information as of December 31, 2015 and 2014 , regarding our operating segments are as follows (in thousands): Real Estate Segment Debt and Preferred Equity Segment Total Company Total revenues Years ended: December 31, 2015 $ 1,481,701 $ 181,128 $ 1,662,829 December 31, 2014 1,341,163 178,815 1,519,978 December 31, 2013 1,177,222 193,843 1,371,065 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 depreciable real estate reserves Years ended: December 31, 2015 $ (63,345 ) $ 153,585 $ 90,240 December 31, 2014 22,178 150,852 173,030 December 31, 2013 (49,793 ) 159,193 109,400 Total assets As of: December 31, 2015 $ 18,175,665 $ 1,682,276 $ 19,857,941 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 years ended December 31, 2015 , 2014 , and 2013 (in thousands): Year ended December 31, 2015 2014 2013 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 depreciable real estate reserves $ 90,240 $ 173,030 $ 109,400 Equity in net gain on sale of interest in unconsolidated joint venture/real estate 15,844 123,253 3,601 Purchase price fair value adjustment 40,078 67,446 (2,305 ) Gain on sale of real estate 175,974 — — Depreciable real estate reserves (19,226 ) — — Income from continuing operations 302,910 363,729 110,696 Net income from discontinued operations 427 19,075 25,687 Gain on sale of discontinued operations 14,122 163,059 14,900 Net income $ 317,459 $ 545,863 $ 151,283

Quarterly Financial Data of t60

Quarterly Financial Data of the Company (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
SL Green Realty Corp
Condensed Income Statements, Captions [Line Items]
Schedule of Quarterly Financial Information	Summarized quarterly financial data for the years ended December 31, 2015 and 2014 , which is reflective of the reclassification of the properties sold or held for sale during 2015 and 2014 as discontinued operations (see Note 4, "Properties Held for Sale and Dispositions"), was as follows (in thousands, except for per share amounts): 2015 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 425,390 $ 432,066 $ 409,074 $ 396,299 Income from continuing operations before equity in net (loss) gain, 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 47,760 11,637 (36,137 ) 33,654 Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate (206 ) 15,281 769 — Purchase price fair value adjustment 40,078 — — — Gain on sale of real estate 16,270 159,704 — — Depreciable real estate reserves — (19,226 ) — — Loss on early extinguishment of debt — — — (49 ) Net income from discontinued operations — — — 427 Gain on sale of discontinued operations 1,139 — — 12,983 Net income (loss) attributable to SL Green 105,041 — 167,396 — (35,368 ) 47,015 Perpetual preferred stock dividends (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income (loss) attributable to SL Green common stockholders $ 101,303 $ 163,658 $ (39,106 ) $ 43,277 Net income (loss) attributable to common stockholders per common share—basic $ 1.02 $ 1.64 $ (0.39 ) $ 0.44 Net income (loss) attributable to common stockholders per common share—diluted $ 1.01 $ 1.64 $ (0.39 ) $ 0.44 2014 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 386,627 $ 390,274 $ 380,631 $ 362,446 Income from continuing before equity in net gain on sale of interest in unconsolidated joint venture/real estate, (loss) gain on early extinguishment of debt, gain on sale of investment in marketable securities, net of noncontrolling interests $ 40,379 $ 46,863 $ 47,035 $ 39,416 Equity in net gain on sale of interest in unconsolidated joint venture/ real estate 673 16,496 1,444 104,640 Purchase price fair value adjustment — (4,000 ) 71,446 — (Loss) gain on early extinguishment of debt (6,865 ) (24,475 ) (1,028 ) 3 Gain on sale of investment in marketable securities 3,895 — — — Net income from discontinued operations 3,626 4,035 5,645 5,769 Gain on sale of discontinued operations 18,817 29,507 114,735 — Net income attributable to SL Green 60,525 68,426 239,277 149,828 Perpetual preferred stock dividends (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income attributable to SL Green common stockholders $ 56,787 $ 64,688 $ 235,539 $ 146,090 Net income attributable to common stockholders per common share—basic $ 0.59 $ 0.68 $ 2.47 $ 1.54 Net income attributable to common stockholders per common share—diluted $ 0.59 $ 0.68 $ 2.46 $ 1.53

Quarterly Financial Data of t61

Quarterly Financial Data of the Operating Partnership (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
SL Green Operating Partnership
Condensed Income Statements, Captions [Line Items]
Schedule of Quarterly Financial Information	Summarized quarterly financial data for the years ended December 31, 2015 and 2014 , which is reflective of the reclassification of the properties sold or held for sale during 2015 and 2014 as discontinued operations (see Note 4, "Properties Held for Sale and Dispositions"), was as follows (in thousands, except for per share amounts): 2015 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 425,390 $ 432,066 $ 409,074 $ 396,299 Income (loss) from continuing operations before equity in net (loss) 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 $ 51,691 $ 18,104 $ (37,714 ) $ 35,397 Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate (206 ) 15,281 769 — Purchase price fair value adjustment 40,078 — — — Gain on sale of real estate 16,270 159,704 — — Depreciable real estate reserves — (19,226 ) — — Loss on early extinguishment of debt — — — (49 ) Net income from discontinued operations — — — 427 Gain on sale of discontinued operations 1,139 — — 12,983 Net income attributable to SLGOP 108,972 173,863 (36,945 ) 48,758 Perpetual preferred units distributions (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income (loss) attributable to SLGOP common unitholders $ 105,234 $ 170,125 $ (40,683 ) $ 45,020 Net income (loss) attributable to common unitholders per common unit—basic $ 1.02 $ 1.64 $ (0.39 ) $ 0.44 Net income (loss) attributable to common unitholders per common unit—diluted $ 1.01 $ 1.64 $ (0.39 ) $ 0.44 2014 Quarter Ended December 31 September 30 June 30 March 31 Total revenues $ 386,627 $ 390,274 $ 380,631 $ 362,446 Income from continuing operations before equity in net gain on sale of interest in unconsolidated joint venture/real estate, (loss) gain on early extinguishment of debt, gain on sale of investment in marketable securities, net of noncontrolling interests $ 42,837 $ 49,499 $ 55,680 $ 44,144 Equity in net gain on sale of interest in unconsolidated joint venture/ real estate 673 16,496 1,444 104,640 Purchase price fair value adjustment — (4,000 ) 71,446 — Gain (loss) on early extinguishment of debt (6,865 ) (24,475 ) (1,028 ) 3 Gain on sale of investment in marketable securities 3,895 — — — Net income from discontinued operations 3,626 4,035 5,645 5,769 Gain on sale of discontinued operations 18,817 29,507 114,735 — Net income attributable to SLGOP 62,983 71,062 247,922 154,556 Perpetual preferred distributions (3,738 ) (3,738 ) (3,738 ) (3,738 ) Net income attributable to SLGOP common unitholders $ 59,245 $ 67,324 $ 244,184 $ 150,818 Net income attributable to common unitholders per common unit—basic $ 0.59 $ 0.68 $ 2.47 $ 1.54 Net income attributable to common unitholders per common unit—diluted $ 0.59 $ 0.68 $ 2.46 $ 1.53

Organization and Basis of Pre62

Organization and Basis of Presentation (Details) - SL Green Operating Partnership	12 Months Ended
	Dec. 31, 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)	3.61%	3.92%
Service Corporation
Organization
Economic interest in variable interest entity (as a percent)	95.00%

Organization and Basis of Pre63

Organization and Basis of Presentation (Schedule of Commercial Office Properties)(Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)ft²buildingshares	Dec. 31, 2014USD ($)
Real estate properties
Number of Properties | building	113
Approximate Square Feet unaudited (sqft)	35,581,060
Weighted Average Occupancy unaudited (as a percent)	90.10%
Debt and preferred equity investments | $	$ 1,670,020	$ 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	91
Approximate Square Feet unaudited (sqft)	32,558,438
Weighted Average Occupancy unaudited (as a percent)	89.80%
Residential
Real estate properties
Number of Properties | building	22
Approximate Square Feet unaudited (sqft)	3,022,622
Weighted Average Occupancy unaudited (as a percent)	94.20%
Managed office properties
Real estate properties
Approximate Square Feet unaudited (sqft)	336,000
Consolidated properties
Real estate properties
Number of Properties | building	74
Approximate Square Feet unaudited (sqft)	27,356,262
Consolidated properties | Commercial properties
Real estate properties
Number of Properties | building	69
Approximate Square Feet unaudited (sqft)	26,527,064
Consolidated properties | Residential
Real estate properties
Number of Properties | building	5
Approximate Square Feet unaudited (sqft)	829,198
Unconsolidated properties
Real estate properties
Number of Properties | building	39
Approximate Square Feet unaudited (sqft)	8,224,798
Unconsolidated properties | Commercial properties
Real estate properties
Number of Properties | building	22
Approximate Square Feet unaudited (sqft)	6,031,374
Unconsolidated properties | Residential
Real estate properties
Number of Properties | building	17
Approximate Square Feet unaudited (sqft)	2,193,424
Manhattan
Real estate properties
Number of Properties | building	59
Approximate Square Feet unaudited (sqft)	27,564,497
Weighted Average Occupancy unaudited (as a percent)	91.70%
Manhattan | Office
Real estate properties
Number of Properties | building	32
Approximate Square Feet unaudited (sqft)	24,028,587
Weighted Average Occupancy unaudited (as a percent)	94.20%
Manhattan | Retail
Real estate properties
Number of Properties | building	18
Approximate Square Feet unaudited (sqft)	756,963
Weighted Average Occupancy unaudited (as a percent)	89.10%
Manhattan | Development/Redevelopment
Real estate properties
Number of Properties | building	7
Approximate Square Feet unaudited (sqft)	1,995,417
Weighted Average Occupancy unaudited (as a percent)	59.00%
Manhattan | Fee Interest
Real estate properties
Number of Properties | building	2
Approximate Square Feet unaudited (sqft)	783,530
Weighted Average Occupancy unaudited (as a percent)	100.00%
Manhattan | Residential
Real estate properties
Number of Properties | building	21
Approximate Square Feet unaudited (sqft)	2,956,011
Weighted Average Occupancy unaudited (as a percent)	94.20%
Manhattan | Consolidated properties
Real estate properties
Number of Properties | building	41
Approximate Square Feet unaudited (sqft)	22,238,764
Manhattan | Consolidated properties | Office
Real estate properties
Number of Properties | building	27
Approximate Square Feet unaudited (sqft)	21,003,606
Manhattan | Consolidated properties | Retail
Real estate properties
Number of Properties | building	9
Approximate Square Feet unaudited (sqft)	408,993
Manhattan | Consolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	3
Approximate Square Feet unaudited (sqft)	42,635
Manhattan | Consolidated properties | Fee Interest
Real estate properties
Number of Properties | building	2
Approximate Square Feet unaudited (sqft)	783,530
Manhattan | Consolidated properties | Residential
Real estate properties
Number of Properties | building	4
Approximate Square Feet unaudited (sqft)	762,587
Manhattan | Consolidated properties | Dual property type, retail portion
Real estate properties
Approximate Square Feet unaudited (sqft)	270,132
Manhattan | Consolidated properties | Dual property type, residential portion
Real estate properties
Approximate Square Feet unaudited (sqft)	222,855
Manhattan | Unconsolidated properties
Real estate properties
Number of Properties | building	18
Approximate Square Feet unaudited (sqft)	5,325,733
Manhattan | Unconsolidated properties | Office
Real estate properties
Number of Properties | building	5
Approximate Square Feet unaudited (sqft)	3,024,981
Manhattan | Unconsolidated properties | Retail
Real estate properties
Number of Properties | building	9
Approximate Square Feet unaudited (sqft)	347,970
Manhattan | Unconsolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	4
Approximate Square Feet unaudited (sqft)	1,952,782
Manhattan | Unconsolidated properties | Fee Interest
Real estate properties
Number of Properties | building	0
Approximate Square Feet unaudited (sqft)	0
Manhattan | Unconsolidated properties | Residential
Real estate properties
Number of Properties | building	17
Approximate Square Feet unaudited (sqft)	2,193,424
Suburban
Real estate properties
Number of Properties | building	32
Approximate Square Feet unaudited (sqft)	4,993,941
Weighted Average Occupancy unaudited (as a percent)	79.20%
Suburban | Office
Real estate properties
Number of Properties | building	29
Approximate Square Feet unaudited (sqft)	4,940,941
Weighted Average Occupancy unaudited (as a percent)	79.00%
Suburban | Retail
Real estate properties
Number of Properties | building	1
Approximate Square Feet unaudited (sqft)	52,000
Weighted Average Occupancy unaudited (as a percent)	100.00%
Suburban | Development/Redevelopment
Real estate properties
Number of Properties | building	2
Approximate Square Feet unaudited (sqft)	1,000
Weighted Average Occupancy unaudited (as a percent)	100.00%
Suburban | Residential
Real estate properties
Number of Properties | building	1
Approximate Square Feet unaudited (sqft)	66,611
Weighted Average Occupancy unaudited (as a percent)	94.40%
Suburban | Consolidated properties
Real estate properties
Number of Properties | building	28
Approximate Square Feet unaudited (sqft)	4,288,300
Suburban | Consolidated properties | Office
Real estate properties
Number of Properties | building	26
Approximate Square Feet unaudited (sqft)	4,235,300
Suburban | Consolidated properties | Retail
Real estate properties
Number of Properties | building	1
Approximate Square Feet unaudited (sqft)	52,000
Suburban | Consolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	1
Approximate Square Feet unaudited (sqft)	1,000
Suburban | Consolidated properties | Residential
Real estate properties
Number of Properties | building	1
Approximate Square Feet unaudited (sqft)	66,611
Suburban | Unconsolidated properties
Real estate properties
Number of Properties | building	4
Approximate Square Feet unaudited (sqft)	705,641
Suburban | Unconsolidated properties | Office
Real estate properties
Number of Properties | building	3
Approximate Square Feet unaudited (sqft)	705,641
Suburban | Unconsolidated properties | Retail
Real estate properties
Number of Properties | building	0
Approximate Square Feet unaudited (sqft)	0
Suburban | Unconsolidated properties | Development/Redevelopment
Real estate properties
Number of Properties | building	1
Approximate Square Feet unaudited (sqft)	0
Suburban | Unconsolidated properties | Residential
Real estate properties
Number of Properties | building	0
Approximate Square Feet unaudited (sqft)	0

Significant Accounting Polici64

Significant Accounting Policies (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Principles of Consolidation
Commercial real estate properties	$ 14,620,896	$ 12,163,976
Mortgages and other loans payable	6,992,504	5,586,709
Assets held for sale	34,981	462,430
Liabilities related to assets held for sale	29,000	266,873
Consolidated VIEs
Principles of Consolidation
Commercial real estate properties	200,700	198,400
Mortgages and other loans payable	$ 104,500	106,500
Consolidated VIEs | Commercial properties
Principles of Consolidation
Assets held for sale		445,000
Liabilities related to assets held for sale		$ 253,900

Significant Accounting Polici65

Significant Accounting Policies (Investments in Commercial Real Estate Properties)(Details) $ in Thousands	Nov. 30, 2015USD ($)	Apr. 30, 2014USD ($)	Dec. 31, 2015USD ($)	May. 31, 2014USD ($)	Dec. 31, 2015USD ($)property	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Investment in Commercial Real Estate Properties
Depreciation expense (including amortization of the capital lease asset)							$ 523,800	$ 338,800	$ 296,500
Number of properties expected to be sold | property					2
Period from cessation of major construction to consider construction project as complete and available for occupancy, maximum (in years)							1 year
Weighted average amortization period for above-market leases (in years)							7 years 4 days
Weighted average amortization period for below-market leases (in years)							20 years 1 month 6 days
Weighted average amortization for in-place lease costs (in years)							21 years 8 months 12 days
Increase in rental revenue from amortization of acquired leases							$ 38,700	23,300	18,800
Write-off of above and in place market leases									6,800
Increase in rental revenue due to write off of balance related to a former tenant									25,600
Reduction in interest expense from amortization of above-market rate mortgages							2,300	5,000	$ 5,000
Identified intangible assets (included in other assets):
Gross amount			$ 939,518		$ 939,518		939,518	664,297
Accumulated amortization			(403,747)		(403,747)		(403,747)	(383,236)
Net			535,771		535,771		535,771	281,061
Identified intangible liabilities (included in deferred revenue):
Gross amount			866,561		866,561		866,561	655,755
Accumulated amortization			(486,928)		(486,928)		(486,928)	(483,948)
Net			379,633		379,633		379,633	$ 171,807
Net intangible assets reclassed to assets held for sale			200		200		200
Net intangible liabilities reclassed to liabilities relates to assets held for sale			100		100		100
Acquired above-market leases, net of acquired below-market leases
Estimated annual amortization
2,016			4,002		4,002		4,002
2,017			2,129		2,129		2,129
2,018			439		439		439
2,019			(376)		(376)		(376)
2,020			(595)		(595)		(595)
All other identifiable assets
Estimated annual amortization
2,016			9,931		9,931		9,931
2,017			8,507		8,507		8,507
2,018			7,207		7,207		7,207
2,019			6,706		6,706		6,706
2,020			6,453		6,453		$ 6,453
600 Lexington Avenue
Investment in Commercial Real Estate Properties
Purchase price fair value adjustment realized	$ 40,078		$ 40,100
388-390 Greenwich Street
Investment in Commercial Real Estate Properties
Purchase price fair value adjustment realized		$ 71,446		$ 71,400
Maximum | Above-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)							14 years
Maximum | Below-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)							14 years
Maximum | In-place leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)							14 years
Minimum | Above-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)							1 year
Minimum | Below-market leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)							1 year
Minimum | In-place leases
Investment in Commercial Real Estate Properties
Estimated useful life of other intangible assets (in years)							1 year
Building (fee ownership)
Investment in Commercial Real Estate Properties
Estimated useful life (in years)							40 years
Building (leasehold interest) | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)							40 years
Furniture and fixtures | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)							7 years
Furniture and fixtures | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)							4 years
Building | Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)							40 years
Building | Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (in years)							3 years
140-150 Grand Street
Investment in Commercial Real Estate Properties
Impairment Charge						$ 19,200	$ 19,200
885 Third Avenue
Investment in Commercial Real Estate Properties
Impairment Charge					$ 6,600
One Vanderbilt
Investment in Commercial Real Estate Properties
Depreciation expense (including amortization of the capital lease asset)							$ 131,800

Significant Accounting Polici66

Significant Accounting Policies (Investment in Marketable Securities)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015
Investment in Marketable Securities
Marketable securities	$ 39,429	$ 45,138
Cost basis	32,400	38,700
Proceeds from sale of marketable securities	4,400
Realized gain (loss) on investment in marketable securities	3,900
Fair Value
Investment in Marketable Securities
Marketable securities	39,429	45,138
Equity marketable securities
Investment in Marketable Securities
Marketable securities	4,332	4,704
Mortgage-backed securities
Investment in Marketable Securities
Marketable securities	$ 35,097	$ 40,434

Significant Accounting Polici67

Significant Accounting Policies (Investments in Unconsolidated Joint Ventures/Deferred Lease Costs/Revenue Recognition/Income Taxes)(Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)joint_venture	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Deferred Lease Costs [Abstract]
Portion of compensation capitalized	$ 15.4	$ 15.1	$ 12.4
Estimated average lease term (in years)	7 years
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	$ 3.1	$ 7.8	$ 4.4
Joint venture
Schedule of Equity Method Investments [Line Items]
Recourse debt	$ 18.4
Number of joint ventures guaranteed with debt recourse | joint_venture	1
Number of joint ventures with performance guarantees under master leases | joint_venture	2

Significant Accounting Polici68

Significant Accounting Policies (Concentrations of Credit Risk/Reclassification)(Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)agreementTenant	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)
Concentration of Credit Risk
Common shares	$ 1,001	$ 974	$ 950	$ 913
Additional paid-in-capital	5,439,735	5,113,759	4,841,800	4,490,084
Treasury shares	(10,000)	0	0	0
Retained earnings	$ 1,643,546	1,607,689	1,475,934	1,556,087
As Previously Reported
Concentration of Credit Risk
Common shares		1,010	986	950
Additional paid-in-capital		5,289,479	5,015,904	4,667,900
Treasury shares		(320,471)	(317,356)	(322,858)
Retained earnings		$ 1,752,404	$ 1,619,150	$ 1,701,092
Workforce concentration
Concentration of Credit Risk
Number of collective bargaining agreements | agreement	6
1515 Broadway
Concentration of Credit Risk
Percentage of concentration (percent)		10.60%
919 Third Avenue
Concentration of Credit Risk
Percentage of concentration (percent)		7.80%
1185 Avenue of the Americas
Concentration of Credit Risk
Percentage of concentration (percent)		7.70%
1 Madison Ave
Concentration of Credit Risk
Percentage of concentration (percent)		6.40%
Annualized rent | Customer concentration
Concentration of Credit Risk
Number of tenants (tenants) | Tenant	3
Maximum percentage of annualized rent for any one tenant not individually disclosed (percent) (more than)	5.00%
Annualized rent | 1515 Broadway | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	10.20%	9.90%
Annualized rent | 388-390 Greenwich Street | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	9.40%	9.80%
Annualized rent | 919 Third Avenue | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	7.80%	7.50%
Annualized rent | 1185 Avenue of the Americas | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	7.50%	7.80%
Annualized rent | 11 Madison Avenue | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	7.50%
Annualized rent | 420 Lexington Avenue | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	6.40%
Annualized rent | 1 Madison Ave | Customer concentration
Concentration of Credit Risk
Percentage of concentration (percent)	5.70%
Collective bargaining arrangements | Workforce concentration
Concentration of Credit Risk
Percentage of concentration (percent)	72.30%
Collective bargaining arrangements expiring in December 2016 | Workforce concentration
Concentration of Credit Risk
Percentage of concentration (percent)	79.20%

Significant Accounting Polici69

Significant Accounting Policies (Reclassification 2)(Details) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Limited partner interests in SLGOP	$ 431,852	$ 521,842
SL Green Operating Partnership
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Limited partner interests in SLGOP		469,524
SL Green partner's capital	7,074,282	6,722,422
Partners' Capital	$ 7,719,317	7,459,216	$ 7,016,876	$ 6,907,103
SL Green Operating Partnership | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Limited partner interests in SLGOP		0
SL Green partner's capital		$ 7,078,924
Common Stock | Partners' Interest | SL Green Operating Partnership
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Partners' Capital Account, Units	99,976	97,325	94,993	91,250
Partners' Capital	$ 7,074,282	$ 6,722,422	$ 6,318,684	$ 6,047,084
Common Stock | Partners' Interest | SL Green Operating Partnership | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Partners' Capital Account, Units		97,325	94,993	91,250
Partners' Capital		$ 7,078,924	$ 6,506,747	$ 6,189,529
Common Stock | Partners' Interest | SL Green Operating Partnership | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Partners' Capital Account, Units		0	0	0
Partners' Capital		$ (356,502)	$ (188,063)	$ (142,445)
Common Stock | Limited Partners | SL Green Operating Partnership
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Limited partner interests in SLGOP		0
Common Stock | Limited Partners | SL Green Operating Partnership | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Limited partner interests in SLGOP		$ 113,298

Property Acquisitions (Details)

Property Acquisitions (Details) $ in Thousands	Nov. 30, 2015USD ($)	Apr. 30, 2014USD ($)	Dec. 31, 2015USD ($)	Aug. 31, 2015USD ($)	Jul. 31, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Oct. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Jul. 31, 2014USD ($)	May. 31, 2014USD ($)	Nov. 30, 2013USD ($)	Apr. 30, 2013USD ($)	Mar. 31, 2013USD ($)unit	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Recognized Identifiable Assets Acquired and Liabilities Assumed
Impact to rental revenue for amortization of aggregate below-market leases															$ 1,245,981	$ 1,121,066	$ 996,782
Impact to depreciation expense															560,887	371,610	$ 324,461
Total fixed rate debt			$ 5,816,010												5,816,010	$ 4,736,709
600 Lexington Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land			97,044												97,044
Building and building leasehold			180,224												180,224
Above market lease value			0												0
Acquired in-place leases			0												0
Other assets, net of other liabilities			0												0
Assets acquired			277,268												277,268
Mark-to-market assumed debt			0												0
Below market lease value			0												0
Derivatives			0												0
Liabilities assumed			0												0
Purchase price	$ 284,000		277,268												$ 277,268
Net consideration funded by us at closing, excluding consideration financed by debt	79,085		79,085
Equity and/or debt investment held	54,575		54,575
Debt assumed	112,795		$ 112,795
Ownership interest in consolidated joint venture (as a percent)			45.00%												45.00%
Value of interest			$ 277,300												$ 277,300
Purchase price fair value adjustment	$ 40,078		40,100
187 Broadway & 5-7 Dey 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
187 Broadway & 5-7 Dey Street | Series R Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units			10,000												10,000
187 Broadway & 5-7 Dey 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%
110 Greene Street | Series P Preferred Units
Recognized Identifiable Assets Acquired and Liabilities Assumed
Issuance of aggregate liquidation preference of preferred units					$ 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
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 | As 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
Building and building leasehold									15,805
Above market lease value									0
Acquired in-place leases									17,345
Other assets, net of other liabilities									0
Assets acquired									238,782
Mark-to-market assumed debt									0
Below market lease value									85,036
Derivatives									0
Liabilities assumed									85,036
Purchase price									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 | As Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land									$ 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 | As Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land										$ 14,400
Building and building leasehold										26,700
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
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 | As 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		$ 1,585,000									1,584,868
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
Value of interest											1,585,000
Purchase price fair value adjustment		$ 71,446									$ 71,400
Economic interest (as a percent)											49.65%
Face amount of loan											$ 1,450,000
Notional value											504,000
Total fixed rate debt								$ 500,000
388-390 Greenwich Street | As Previously Reported
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land											558,700
Building and building leasehold											$ 1,000,000
315 West 33rd Street
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land												$ 195,834
Building and building leasehold												164,429
Above market lease value												7,084
Acquired in-place leases												26,125
Other assets, net of other liabilities												1,142
Assets acquired												394,614
Mark-to-market assumed debt												0
Below market lease value												7,839
Liabilities assumed												7,839
Purchase price												386,775
Net consideration funded by us at closing, excluding consideration financed by debt												386,775
Equity and/or debt investment held												0
Debt assumed												0
Assemblage of Retail Properties on Fifth Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land												135,513
Building and building leasehold												10,487
Above market lease value												0
Acquired in-place leases												0
Other assets, net of other liabilities												0
Assets acquired												146,000
Mark-to-market assumed debt												0
Below market lease value												0
Liabilities assumed												0
Purchase price												146,000
Net consideration funded by us at closing, excluding consideration financed by debt												146,000
Equity and/or debt investment held												0
Debt assumed												$ 0
16 Court
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land													$ 19,217
Building and building leasehold													63,210
Above market lease value													5,122
Acquired in-place leases													9,422
Other assets, net of other liabilities													3,380
Assets acquired													100,351
Mark-to-market assumed debt													294
Below market lease value													3,885
Liabilities assumed													4,179
Purchase price													96,172
Net consideration funded by us at closing, excluding consideration financed by debt													4,000
Equity and/or debt investment held													13,835
Debt assumed													84,642
Purchase price fair value adjustment													(2,300)
Mortgage encumbering the property													$ 84,600
248-252 Bedford Avenue
Recognized Identifiable Assets Acquired and Liabilities Assumed
Land														$ 10,865
Building and building leasehold														44,035
Above market lease value														0
Acquired in-place leases														0
Other assets, net of other liabilities														0
Assets acquired														54,900
Mark-to-market assumed debt														0
Below market lease value														0
Liabilities assumed														0
Purchase price														54,900
Net consideration funded by us at closing, excluding consideration financed by debt														21,782
Equity and/or debt investment held														0
Debt assumed														0
Face amount of loan														$ 22,000
Number of units | unit														84
Stated interest rate of preferred partnership units issued (as a percent)														90.00%
248-252 Bedford Avenue | Apartments
Recognized Identifiable Assets Acquired and Liabilities Assumed
Number of units | unit														72
248-252 Bedford Avenue | Townhouses
Recognized Identifiable Assets Acquired and Liabilities Assumed
Number of units | unit														12
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 - Schedul

Property Acquisitions - Schedule of Fair Value of Equity Interest Immediately Before Acquisition Date (Details) - USD ($) $ in Thousands	Nov. 30, 2015	Apr. 30, 2014	Dec. 31, 2015	May. 31, 2014
600 Lexington Avenue
Property Acquisitions
Contract purchase price	$ 284,000		$ 277,268
Net consideration funded by us at closing, excluding consideration financed by debt	(79,085)		(79,085)
Debt assumed	(112,795)		(112,795)
Fair value of retained equity interest	92,120
Equity and/or debt investment held	(54,575)		(54,575)
Other	2,533
Purchase price fair value adjustment	$ 40,078		$ 40,100
388-390 Greenwich Street
Property Acquisitions
Contract purchase price		$ 1,585,000		$ 1,584,868
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		$ 71,446		$ 71,400

Property Acquisitions - Pro For

Property Acquisitions - Pro Forma (Details) - 11 Madison Avenue - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property Acquisitions
Actual revenues since acquisition	$ 29,865
Actual net income since acquisition	159
Pro forma revenues	1,657,937	$ 1,540,525
Pro forma income from continuing operations	$ 102,440	$ 376,710
Pro forma basic earnings per share (in usd per share)	$ 0.76	$ 7
Pro forma diluted earnings per share (in usd per share)	$ 0.75	$ 6.92
Mortgage loan
Property Acquisitions
Fixed rate debt	$ 1,400,000	$ 1,400,000
Term (in Years)	10 years	10 years
Interest rate, fixed rate debt (as a percent)	3.838%	3.838%
SL Green Operating Partnership
Property Acquisitions
Pro forma basic earnings per share (in usd per share)	$ 0.76	$ 7
Pro forma diluted earnings per share (in usd per share)	$ 0.75	$ 6.92

Properties Held for Sale and 73

Properties Held for Sale and Property Dispositions - Properties Held for Sale (Details) - 248-252 Bedford Avenue $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Property Dispositions and Assets Held for Sale
Ownership percentage in disposed asset	90.00%
Agreed sale consideration	$ 55

Properties Held for Sale and 74

Properties Held for Sale and Property Dispositions - Property Dispositions (Details) $ in Thousands	1 Months Ended										3 Months Ended	12 Months Ended
	Dec. 31, 2015USD ($)ft²	Sep. 30, 2015USD ($)ft²	Aug. 31, 2015USD ($)ft²	Jan. 31, 2015USD ($)ft²	Nov. 30, 2014USD ($)ft²	Jul. 31, 2014USD ($)ft²	May. 31, 2014USD ($)ft²	Sep. 30, 2013USD ($)ft²	Aug. 31, 2013USD ($)ft²	Feb. 28, 2013USD ($)ft²	Sep. 30, 2015USD ($)ft²	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²	35,581,060											35,581,060
Gain on Sale												$ 14,122	$ 163,059	$ 14,900
Revenues
Rental revenue												236	51,090	94,558
Escalation and reimbursement revenues												(127)	4,646	14,856
Other income												0	23	554
Total revenues												109	55,759	109,968
Operating expenses												(631)	7,772	20,568
Real estate taxes												250	7,156	16,521
Ground rent												0	3,001	7,975
Transaction related costs												(49)	89	2
Depreciable real estate reserves												0	0	2,150
Interest expense, net of interest income												109	12,652	19,782
Amortization of deferred financing costs												3	433	840
Depreciation and amortization												0	5,581	16,443
Total expenses												(318)	36,684	84,281
Net income from discontinued operations												$ 427	$ 19,075	$ 25,687
140-150 Grand Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²	215,100											215,100
Sales Price	$ 32,000
Gain on Sale	$ (20,100)
Impairment Charge											$ 19,200	$ 19,200
570 & 574 Fifth Avenue
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²	24,327											24,327
Sales Price	$ 125,400
Gain on Sale	24,600
Employee compensation award	$ 4,000
120 West 45th Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²		440,000									440,000
Sales Price		$ 365,000
Gain on Sale		58,600
Employee compensation award		$ 2,000
131-137 Spring Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²			68,342
Sales Price			$ 277,800
Gain on Sale			101,100
Employee compensation award			$ 4,100
Ownership percentage in disposed asset			80.00%
180 Maiden Lane
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²				1,090,000
Sales Price				$ 470,000
Gain on Sale				17,000
Employee compensation award				$ 800
2 Herald Square
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²					354,400
Sales Price					$ 365,000
Gain on Sale					18,800
Employee compensation award					$ 2,500
985-987 Third Avenue
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²						13,678
Sales Price						$ 68,700
Gain on Sale						29,800
Employee compensation award						$ 1,300
673 First Avenue
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²							422,000
Sales Price							$ 145,000
Gain on Sale							117,600
Employee compensation award							$ 3,400
300 Main Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²								130,000
Sales Price								$ 13,500
Gain on Sale								$ (2,200)
333 West 34th Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²									345,400
Sales Price									$ 220,300
Gain on Sale									13,800
Employee compensation award									$ 3,000
44 West 55th Street
Properties Sold [Abstract]
Approximate Usable Square Feet (sqft) | ft²										8,557
Sales Price										$ 6,300
Gain on Sale										$ 1,100

Debt and Preferred Equity Inv75

Debt and Preferred Equity Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2014
Debt investment
Increase in debt and preferred equity investments (net of discounts), including investments classified as held-for-sale	$ 781,400	$ 680,100
Decrease in debt and preferred equity investments (net of discounts), including investments classified as held-for-sale	$ 520,200	576,100
Aggregate weighted average current yield (as a percent)	10.23%
Debt Investments Held [Abstract]
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,670,020	1,408,804
Debt investment
Debt Investments Held [Abstract]
Future Funding Obligations	131,430
Senior Financing	5,693,825
Carrying Value, Net of Discounts and Deferred Origination Fees	1,627,844	1,275,809
Total fixed rate
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	2,762,980
Carrying Value, Net of Discounts and Deferred Origination Fees	511,389	607,084
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	23,510	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, July 2016
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	115,000
Carrying Value, Net of Discounts and Deferred Origination Fees	24,916	24,910
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	72,102	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	104,661	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	66,183	65,770
Total fixed rate | Mezzanine Loan, June 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	502,100
Carrying Value, Net of Discounts and Deferred Origination Fees	41,115	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	49,691	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	26,262	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	513	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	89,880
Carrying Value, Net of Discounts and Deferred Origination Fees	19,936	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/Mezzanine Loan Repaid in December 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	0	70,688
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	131,430
Senior Financing	2,930,845
Carrying Value, Net of Discounts and Deferred Origination Fees	1,116,455	668,725
Total floating rate | Mezzanine Loan, November 2016
Debt Investments Held [Abstract]
Future Funding Obligations	7,942
Senior Financing	312,939
Carrying Value, Net of Discounts and Deferred Origination Fees	66,398	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	74,700	73,402
Total floating rate | Mortgage/Mezzanine Loan, April 2016
Debt Investments Held [Abstract]
Future Funding Obligations	10,156
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	94,901	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	22,625	22,573
Amount participated out	7,400
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	99,530	99,023
Total floating rate | Mezzanine Loan, December 2016
Debt Investments Held [Abstract]
Future Funding Obligations	11,414
Senior Financing	131,939
Carrying Value, Net of Discounts and Deferred Origination Fees	49,751	42,750
Total floating rate | Mezzanine Loan, December 2016
Debt Investments Held [Abstract]
Future Funding Obligations	281
Senior Financing	39,201
Carrying Value, Net of Discounts and Deferred Origination Fees	13,731	11,835
Total floating rate | Mortgage/Mezzanine Loan, January 2017
Debt Investments Held [Abstract]
Future Funding Obligations	57,108
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	134,264	0
Amount participated out	25,000
Total floating rate | Mezzanine Loan, January 2017
Debt Investments Held [Abstract]
Future Funding Obligations	1,293
Senior Financing	118,949
Carrying Value, Net of Discounts and Deferred Origination Fees	28,551	20,651
Total floating rate | Mortgage/Mezzanine Loan , June 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	68,977	0
Total floating rate | Jr. Mortgage Participation/Mezzanine Loan, July 2017
Debt Investments Held [Abstract]
Future Funding Obligations	1,257
Senior Financing	118,717
Carrying Value, Net of Discounts and Deferred Origination Fees	40,346	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	22,877	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	16,901	16,848
Total floating rate | Mortgage/Mezzanine Loan, October 2017
Debt Investments Held [Abstract]
Future Funding Obligations	4,500
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	19,282	0
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	14,904	14,859
Total floating rate | Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	85,000
Carrying Value, Net of Discounts and Deferred Origination Fees	29,505	0
Total floating rate | Mezzanine Loan, December 2017
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	65,000
Carrying Value, Net of Discounts and Deferred Origination Fees	28,563	0
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	14,942	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	19,846	0
Total floating rate | Mezzanine Loan, April 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	175,000
Carrying Value, Net of Discounts and Deferred Origination Fees	34,725	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	20,510	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	31,210	$ 0
Total floating rate | Mezzanine Loan, December 2018
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	33,000
Carrying Value, Net of Discounts and Deferred Origination Fees	26,777
Total floating rate | Mezzanine Loan, December 2018
Debt Investments Held [Abstract]
Future Funding Obligations	6,383
Senior Financing	156,383
Carrying Value, Net of Discounts and Deferred Origination Fees	52,774	$ 0
Total floating rate | Mezzanine Loan, December 2018
Debt Investments Held [Abstract]
Future Funding Obligations	28,801
Senior Financing	206,717
Carrying Value, Net of Discounts and Deferred Origination Fees	49,625	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	18,395	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	21,845	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
Total floating rate | Mezzanine Loan Repaid in November 2015
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 0	$ 49,614

Debt and Preferred Equity Inv76

Debt and Preferred Equity Investments (Preferred Equity Investments)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Preferred equity investment
Aggregate weighted average current yield (as a percent)	10.23%
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,670,020	$ 1,408,804
Preferred equity investments
Preferred equity investment
Aggregate weighted average current yield (as a percent)	7.86%
Future Funding Obligations	$ 5,580
Senior Financing	131,669
Carrying Value, Net of Discounts and Deferred Origination Fees	42,176	132,995
Preferred Equity, March 2018
Preferred equity investment
Future Funding Obligations	0
Senior Financing	71,486
Carrying Value, Net of Discounts and Deferred Origination Fees	9,967	9,954
Preferred Equity, November 2018
Preferred equity investment
Future Funding Obligations	5,580
Senior Financing	60,183
Carrying Value, Net of Discounts and Deferred Origination Fees	32,209	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 Inv77

Debt and Preferred Equity Investments (Rollforward of Total Allowance for Loan Loss Reserves)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loan loss reserve activity
Balance at beginning of year	$ 0	$ 1,000	$ 7,000
Expensed	0	0	0
Recoveries	0	0	0
Charge-offs and reclassifications	0	(1,000)	(6,000)
Balance at end of year	$ 0	$ 0	$ 1,000

Debt and Preferred Equity Inv78

Debt and Preferred Equity Investments (Narrative)(Details)	12 Months Ended
	Dec. 31, 2015USD ($)segment	Dec. 31, 2014USD ($)segment	Dec. 31, 2013USD ($)
Preferred equity investment
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,670,020,000	$ 1,408,804,000
Number of portfolio segments of financial receivables (segment) | segment	1	1
Additional amount of financing receivables included in other assets	$ 121,500,000	$ 133,500,000
Junior Mortgage Participation Acquired in September 2014
Preferred equity investment
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 0	$ 0	$ 0

Investments in Unconsolidated79

Investments in Unconsolidated Joint Ventures (Details) $ in Thousands	1 Months Ended					3 Months Ended
	Oct. 31, 2015USD ($)	Aug. 31, 2015USD ($)ft²	Jul. 31, 2015USD ($)	Mar. 31, 2015USD ($)	Feb. 28, 2015USD ($)property	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)ft²unit	Dec. 31, 2014USD ($)
General information on each joint venture
Net equity investment in VIEs in which the entity is not primary beneficiary							$ 99,600	$ 146,200
Approximate Square Feet (sqft) | ft²							35,581,060
131-137 Spring Street
General information on each joint venture
Approximate Square Feet (sqft) | ft²		68,342
Agreed sale consideration		$ 277,800
Ownership percentage in disposed asset		80.00%
Series M Preferred Units
General information on each joint venture
Preferred Units (as a percent)					3.75%
100 Park Avenue
General information on each joint venture
Ownership Percentage							49.90%
Economic Interest (as a percent)							49.90%
Approximate Square Feet (sqft) | ft²							834,000
Acquisition Price							$ 95,800
717 Fifth Avenue
General information on each joint venture
Ownership Percentage							10.92%
Economic Interest (as a percent)							10.92%
Approximate Square Feet (sqft) | ft²							119,500
Acquisition Price							$ 251,900
800 Third Avenue
General information on each joint venture
Ownership Percentage							60.52%
Economic Interest (as a percent)							60.52%
Approximate Square Feet (sqft) | ft²							526,000
Acquisition Price							$ 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 Percentage							56.88%
Economic Interest (as a percent)							56.88%
Approximate Square Feet (sqft) | ft²							674,000
Acquisition Price							$ 520,000
Jericho Plaza
General information on each joint venture
Ownership Percentage							77.78%
Economic Interest (as a percent)							77.78%
Approximate Square Feet (sqft) | ft²							640,000
Acquisition Price							$ 210,000
Additional Ownership Percentage Acquired (less than for the 1.0%)	57.52%
11 West 34th Street
General information on each joint venture
Ownership Percentage							30.00%
Economic Interest (as a percent)							30.00%
Approximate Square Feet (sqft) | ft²							17,150
Acquisition Price							$ 10,800
7 Renaissance
General information on each joint venture
Ownership Percentage							50.00%
Economic Interest (as a percent)							50.00%
Approximate Square Feet (sqft) | ft²							65,641
Acquisition Price							$ 4,000
7 Renaissance | Subsequent Event
General information on each joint venture
Agreed sale consideration						$ 20,700
3 Columbus Circle
General information on each joint venture
Ownership Percentage							48.90%
Economic Interest (as a percent)							48.90%
Approximate Square Feet (sqft) | ft²							741,500
Acquisition Price							$ 500,000
280 Park Avenue
General information on each joint venture
Ownership Percentage							50.00%
Economic Interest (as a percent)							50.00%
Approximate Square Feet (sqft) | ft²							1,219,158
Acquisition Price							$ 400,000
1552-1560 Broadway
General information on each joint venture
Ownership Percentage							50.00%
Economic Interest (as a percent)							50.00%
Approximate Square Feet (sqft) | ft²							35,897
Acquisition Price							$ 136,550
724 Fifth Avenue
General information on each joint venture
Ownership Percentage							50.00%
Economic Interest (as a percent)							50.00%
Approximate Square Feet (sqft) | ft²							65,040
Acquisition Price							$ 223,000
10 East 53rd Street
General information on each joint venture
Ownership Percentage							55.00%
Economic Interest (as a percent)							55.00%
Approximate Square Feet (sqft) | ft²							354,300
Acquisition Price							$ 252,500
33 Beekman
General information on each joint venture
Ownership Percentage							45.90%
Economic Interest (as a percent)							45.90%
Approximate Square Feet (sqft) | ft²							163,500
Acquisition Price							$ 31,000
Agreed sale consideration	$ 196,000
521 Fifth Avenue
General information on each joint venture
Ownership Percentage							50.50%
Economic Interest (as a percent)							50.50%
Approximate Square Feet (sqft) | ft²							460,000
Acquisition Price							$ 315,000
21 East 66th Street
General information on each joint venture
Ownership Percentage							32.28%
Economic Interest (as a percent)							32.28%
Approximate Square Feet (sqft) | ft²							16,736
Acquisition Price							$ 75,000
21 East 66th Street | Three Retail and Two Residential Units
General information on each joint venture
Ownership Percentage							32.28%
Number of Stores | unit							3
Number Of Residential Units | unit							2
21 East 66th Street | Three Residential Units
General information on each joint venture
Ownership Percentage							16.14%
Number Of Residential Units | unit							3
650 Fifth Avenue
General information on each joint venture
Ownership Percentage							50.00%
Economic Interest (as a percent)							50.00%
Approximate Square Feet (sqft) | ft²							32,324
Acquisition Price							$ 0
121 Greene Street
General information on each joint venture
Ownership Percentage							50.00%
Economic Interest (as a percent)							50.00%
Approximate Square Feet (sqft) | ft²							7,131
Acquisition Price							$ 27,400
175-225 Third Street Brooklyn, New York
General information on each joint venture
Ownership Percentage							95.00%
Economic Interest (as a percent)							95.00%
Approximate Square Feet (sqft) | ft²							0
Acquisition Price							$ 74,600
55 West 46th Street
General information on each joint venture
Ownership Percentage							25.00%
Economic Interest (as a percent)							25.00%
Approximate Square Feet (sqft) | ft²							347,000
Acquisition Price							$ 295,000
Stonehenge Portfolio
General information on each joint venture
Approximate Square Feet (sqft) | ft²							2,046,733
Acquisition Price					$ 40,200		$ 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
Stonehenge Portfolio | Series M Preferred Units
General information on each joint venture
Issuance of aggregate liquidation preference of preferred units					$ 40,000
131-137 Spring Street
General information on each joint venture
Ownership Percentage							20.00%
Economic Interest (as a percent)							20.00%
Approximate Square Feet (sqft) | ft²							68,342
Acquisition Price							$ 277,750
1552 Broadway
General information on each joint venture
Approximate Square Feet (sqft) | ft²							13,045

Investments in Unconsolidated80

Investments in Unconsolidated Joint Ventures Investments in Unconsolidated Joint Ventures (Acquisition, Development and Construction Arrangements/Sale of Joint Venture Interest or Property)(Details) $ in Thousands	1 Months Ended							12 Months Ended
	Sep. 30, 2015USD ($)	Aug. 31, 2015USD ($)	Sep. 30, 2014USD ($)	May. 31, 2014USD ($)unit	Mar. 31, 2014USD ($)	Jan. 31, 2014USD ($)ft²	Dec. 31, 2013USD ($)joint_venture	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)joint_ventureproperty
Schedule of Equity Method Investments [Line Items]
Acquisition, development and construction arrangements, carrying value								$ 145,878	$ 145,875
Gain (Loss) on Sale								$ 14,122	163,059	$ 14,900
Approximate Square Feet (sqft) | ft²								35,581,060
West Coast Office portfolio
Schedule of Equity Method Investments [Line Items]
Number of apartment units | unit				1
West Coast Office Portfolio
Schedule of Equity Method Investments [Line Items]
Number of Joint Venture Properties with an Increased Ownership Interest | joint_venture							2			2
Mezzanine loan and preferred equity due March 2016
Schedule of Equity Method Investments [Line Items]
Acquisition, development and construction arrangements, carrying value								$ 99,936	99,629
Mezzanine loan due February 2022
Schedule of Equity Method Investments [Line Items]
Acquisition, development and construction arrangements, carrying value								$ 45,942	$ 46,246
The Meadows
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		50.00%
Gross Asset Valuation		$ 121,100
Gain (Loss) on Sale		$ (1,600)
315 West 36th Street
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	35.50%
Gross Asset Valuation	$ 115,000
Gain (Loss) on Sale	16,300
Employee compensation award	$ 1,200
180 Broadway
Schedule of Equity Method Investments [Line Items]
Ownership Percentage			25.50%
Gross Asset Valuation			$ 222,500
Gain (Loss) on Sale			16,500
Promote recognized			$ 3,300
747 Madison Avenue
Schedule of Equity Method Investments [Line Items]
Ownership Percentage				33.33%
Gross Asset Valuation				$ 160,000
Gain (Loss) on Sale				0
Promote recognized				10,300
Preferred equity investment				30,000
Deferred gain on sale				$ 13,100
West Coast Office portfolio
Schedule of Equity Method Investments [Line Items]
Ownership Percentage					42.02%
Gross Asset Valuation					$ 756,000
Gain (Loss) on Sale					$ 85,600
Number of apartment units | unit				5
21-25 West 34th Street
Schedule of Equity Method Investments [Line Items]
Ownership Percentage						49.90%
Gross Asset Valuation						$ 114,900
Gain (Loss) on Sale						$ 20,900
Approximate Square Feet (sqft) | ft²						91,300
27-29 West 34th Street
Schedule of Equity Method Investments [Line Items]
Ownership Percentage							50.00%			50.00%
Gross Asset Valuation							$ 70,100			$ 70,100
Gain (Loss) on Sale							7,600
Employee compensation award							$ 1,500
West Coast Office Portfolio
Schedule of Equity Method Investments [Line Items]
Ownership Percentage							42.04%			42.04%
Gross Asset Valuation							$ 224,300			$ 224,300
Gain (Loss) on Sale										$ 2,100
Number of properties sold | property										3
Economic Interest (as a percent)							43.74%			43.74%
West Coast Office Portfolio, Two Joint Venture Partners
Schedule of Equity Method Investments [Line Items]
Ownership Percentage							14.39%			14.39%
Herald Center | Preferred equity
Schedule of Equity Method Investments [Line Items]
Interest rate (as a percent)							8.75%			8.75%
Joint venture | 747 Madison Avenue | 30 East 65th Street
Schedule of Equity Method Investments [Line Items]
Investment's ownership percentage in joint venture				100.00%

Investments in Unconsolidated81

Investments in Unconsolidated Joint Ventures (Mortgages and Other Loans Payable)(Details) - USD ($) $ in Thousands	Feb. 24, 2016	Sep. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Total fixed rate debt				$ 5,816,010	$ 4,736,709
Total floating rate debt				1,205,494	1,103,942
Total fixed rate and floating rate debt				7,021,504	5,840,651
Gain (loss) on early extinguishment of debt				(49)	(32,365)	$ (18,518)
1745 Broadway
Debt Instrument [Line Items]
Total fixed rate debt				16,000	16,000
3 Columbus Circle
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt			$ (800)
315 West 36th Street
Debt Instrument [Line Items]
Agreed sale consideration		$ 115,000
600 Lexington Avenue
Debt Instrument [Line Items]
Total floating rate debt				112,795	0
Joint venture
Debt Instrument [Line Items]
Total fixed rate debt				2,808,881	2,065,264
Total floating rate debt				1,500,232	1,713,440
Total fixed rate and floating rate debt				4,309,113	3,778,704
Maximum amount of loan recourse to entity				18,400
Joint venture | 280 Park Avenue
Debt Instrument [Line Items]
Total fixed rate debt				692,963	700,171
Joint venture | 7 Renaissance
Debt Instrument [Line Items]
Total fixed rate debt				2,927	2,147
Joint venture | 1745 Broadway
Debt Instrument [Line Items]
Total fixed rate debt				340,000	340,000
Joint venture | Jericho Plaza
Debt Instrument [Line Items]
Total fixed rate debt				163,750	163,750
Joint venture | 800 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt				20,910	20,910
Joint venture | 521 Fifth Avenue
Debt Instrument [Line Items]
Total fixed rate debt				170,000	170,000
Joint venture | 717 Fifth Avenue | Mortgage loan
Debt Instrument [Line Items]
Committed amount				300,000
Joint venture | 717 Fifth Avenue | Mezzanine loans
Debt Instrument [Line Items]
Committed amount				290,000
Joint venture | 717 Fifth Avenue | Initial Maturity July 2022
Debt Instrument [Line Items]
Total fixed rate debt				300,000	300,000
Joint venture | 717 Fifth Avenue | Initial Maturity July 2024
Debt Instrument [Line Items]
Total fixed rate debt				325,704	314,381
Joint venture | 21 East 66th Street
Debt Instrument [Line Items]
Total fixed rate debt				12,000	12,000
Total floating rate debt				1,805	1,883
Joint venture | 3 Columbus Circle
Debt Instrument [Line Items]
Total fixed rate debt				350,000	0
Total floating rate debt				0	230,974
Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Total fixed rate debt				430,627	0
Total floating rate debt				10,500	0
Joint venture | Stonehenge Portfolio | Initial Maturity July 2016
Debt Instrument [Line Items]
Total fixed rate debt				13,300
Joint venture | Stonehenge Portfolio | Initial Maturity June 2017
Debt Instrument [Line Items]
Total fixed rate debt				55,500
Joint venture | Stonehenge Portfolio | Initial Maturity November 2017
Debt Instrument [Line Items]
Total fixed rate debt				35,000
Joint venture | Stonehenge Portfolio | Initial Maturity February 2018
Debt Instrument [Line Items]
Total fixed rate debt				7,300
Joint venture | Stonehenge Portfolio | Initial Maturity August 2019
Debt Instrument [Line Items]
Total fixed rate debt				141,500
Joint venture | Stonehenge Portfolio | Initial Maturity June 2024
Debt Instrument [Line Items]
Total fixed rate debt				177,900
Joint venture | 315 West 36th Street
Debt Instrument [Line Items]
Total fixed rate debt				0	25,000
Joint venture | 11 West 34th Street
Debt Instrument [Line Items]
Total fixed rate debt				0	16,905
Total floating rate debt				23,000	0
Joint venture | 1552 Broadway
Debt Instrument [Line Items]
Total floating rate debt				190,409	184,210
Joint venture | 1552 Broadway | Mortgage loan
Debt Instrument [Line Items]
Committed amount				150,000
Unfunded amount				600
Joint venture | 1552 Broadway | Mezzanine loans
Debt Instrument [Line Items]
Committed amount				41,500
Unfunded amount				500
Joint venture | Other loan payable
Debt Instrument [Line Items]
Total floating rate debt				30,000	30,000
Joint venture | 650 Fifth Avenue
Debt Instrument [Line Items]
Total floating rate debt				65,000	65,000
Joint venture | 650 Fifth Avenue | Mortgage loan
Debt Instrument [Line Items]
Committed amount				97,000
Unfunded amount				32,000
Joint venture | 175-225 Third Street Brooklyn, New York
Debt Instrument [Line Items]
Total floating rate debt				40,000	40,000
Joint venture | 10 East 53rd Street
Debt Instrument [Line Items]
Total floating rate debt				125,000	125,000
Joint venture | 724 Fifth Avenue
Debt Instrument [Line Items]
Total floating rate debt				275,000	275,000
Joint venture | 33 Beekman
Debt Instrument [Line Items]
Total floating rate debt				73,518	52,283
Maximum amount of loan recourse to entity				75,000
Joint venture | 55 West 46th Street
Debt Instrument [Line Items]
Total floating rate debt				150,000	150,000
Joint venture | 55 West 46th Street | Mortgage loan
Debt Instrument [Line Items]
Committed amount				190,000
Unfunded amount				40,000
Joint venture | 121 Greene Street
Debt Instrument [Line Items]
Total floating rate debt				15,000	15,000
Joint venture | 100 Park Avenue
Debt Instrument [Line Items]
Total floating rate debt				360,000	360,000
Joint venture | 131-137 Spring Street
Debt Instrument [Line Items]
Total floating rate debt				141,000	0
Joint venture | The Meadows
Debt Instrument [Line Items]
Total floating rate debt				0	67,350
Joint venture | 600 Lexington Avenue
Debt Instrument [Line Items]
Total floating rate debt				$ 0	$ 116,740
Weighted Average | 1745 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				4.81%
Weighted Average | 600 Lexington Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				2.30%
Weighted Average | Joint venture | 280 Park Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				6.57%
Weighted Average | Joint venture | 7 Renaissance
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				10.00%
Weighted Average | Joint venture | 1745 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				5.68%
Weighted Average | Joint venture | Jericho Plaza
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				5.65%
Weighted Average | Joint venture | 800 Third Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				6.00%
Weighted Average | Joint venture | 521 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				3.73%
Weighted Average | Joint venture | 717 Fifth Avenue | Initial Maturity July 2022
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				4.45%
Weighted Average | Joint venture | 717 Fifth Avenue | Initial Maturity July 2024
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				9.00%
Weighted Average | Joint venture | 21 East 66th Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				3.60%
Interest rate, floating rate debt (as a percent)				2.97%
Weighted Average | Joint venture | 3 Columbus Circle
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				3.45%
Weighted Average | Joint venture | Stonehenge Portfolio
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)				4.18%
Interest rate, floating rate debt (as a percent)				3.25%
Weighted Average | Joint venture | 11 West 34th Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				4.57%
Weighted Average | Joint venture | 1552 Broadway
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				4.35%
Weighted Average | Joint venture | Other loan payable
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				1.09%
Weighted Average | Joint venture | 650 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				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)				4.26%
Weighted Average | Joint venture | 10 East 53rd Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				2.70%
Weighted Average | Joint venture | 724 Fifth Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				2.61%
Weighted Average | Joint venture | 33 Beekman
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				2.94%
Weighted Average | Joint venture | 55 West 46th Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				2.50%
Weighted Average | Joint venture | 121 Greene Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				1.70%
Weighted Average | Joint venture | 100 Park Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				1.95%
Weighted Average | Joint venture | 131-137 Spring Street
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)				1.76%
Subsequent Event | Joint venture | Jericho Plaza
Debt Instrument [Line Items]
Total floating rate debt	$ 75,000
Ownership Percentage	11.67%
Term (in Years)	2 years
Face amount of loan	$ 100,000

Investments in Unconsolidated82

Investments in Unconsolidated Joint Ventures (Schedules of Combined Financial Statements for the Unconsolidated Joint Ventures)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets
Commercial real estate property, net	$ 14,620,896	$ 12,163,976
Other assets	850,719	647,333
Liabilities and members' equity
Mortgages and other loans payable	6,992,504	5,586,709
Company's investments in unconsolidated joint ventures	1,203,858	1,172,020
Combined statements of income for the unconsolidated joint ventures
Operating expenses	301,624	282,283	$ 276,589
Ground rent	32,834	32,307	31,951
Real estate taxes	232,702	217,843	203,076
Interest expense, net of interest income	323,870	317,400	310,894
Amortization of deferred financing costs	27,348	22,377	15,855
Transaction related costs	11,430	8,707	3,985
Depreciation and amortization	560,887	371,610	324,461
Total expenses	1,585,568	1,345,015	1,253,003
Company's equity in net income from unconsolidated joint ventures	13,028	26,537	9,921
Joint venture
Assets
Commercial real estate property, net	6,122,468	5,275,632
Other assets	904,283	810,567
Total assets	7,026,751	6,086,199
Liabilities and members' equity
Mortgages and other loans payable	4,309,113	3,778,704
Other liabilities	523,160	485,572
Members' equity	2,194,478	1,821,923
Total liabilities and members' equity	7,026,751	6,086,199
Company's investments in unconsolidated joint ventures	1,203,858	1,172,020
Combined statements of income for the unconsolidated joint ventures
Total revenues	576,845	522,132	628,649
Operating expenses	106,613	82,436	114,633
Ground rent	14,083	9,898	2,863
Real estate taxes	89,734	64,217	71,755
Interest expense, net of interest income	199,126	178,743	225,765
Amortization of deferred financing costs	13,394	12,395	17,092
Transaction related costs	615	535	808
Depreciation and amortization	149,023	137,793	192,504
Total expenses	572,588	486,017	625,420
Loss on early extinguishment of debt	(1,089)	(6,743)	0
Net income before gain on sale	3,168	29,372	3,229
Company's equity in net income from unconsolidated joint ventures	13,028	26,537	9,921
Joint venture
Investment in Unconsolidated Joint Ventures
Management fees, base revenue	$ 6,900	$ 16,900	$ 4,700

Deferred Costs (Details)

Deferred Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing	$ 415,406	$ 385,555
Deferred financing	241,775	193,776
Deferred costs, gross	657,181	579,331
Less accumulated amortization	(286,746)	(251,369)
Deferred costs, net	$ 370,435	$ 327,962

Mortgages and Other Loans Pay84

Mortgages and Other Loans Payable (Details)	Dec. 06, 2015USD ($)	Dec. 31, 2015USD ($)advance$ / shares	Feb. 28, 2015	Jan. 31, 2015	Dec. 31, 2014USD ($)	Oct. 31, 2014USD ($)	May. 31, 2014USD ($)
Debt Instrument [Line Items]
Total fixed rate debt		$ 5,816,010,000			$ 4,736,709,000
Total floating rate debt		1,205,494,000			1,103,942,000
Total fixed rate and floating rate debt		7,021,504,000			5,840,651,000
Mortgages reclassed to liabilities related to assets held for sale		(29,000,000)			(253,942,000)
Total mortgages and other loans payable		6,992,504,000			5,586,709,000
Federal Home Loan Bank Advances outstanding		$ 45,800,000
Federal Home Loan Bank, advances, weighted-average borrowing rate (as a percent)		0.55%
Book value of collateral		$ 10,800,000,000			8,200,000,000
Series J Preferred Units
Debt Instrument [Line Items]
Total fixed rate debt		4,000,000			4,000,000
Temporary Equity, Carrying Amount, Attributable to Noncontrolling Interest		$ 4,000,000
Preferred Units (as a percent)		3.75%
Preferred Units, liquidation preference (in dollars per unit) | $ / shares		$ 1,000
Series J Preferred Units | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		3.75%
Master Repurchase Agreement
Debt Instrument [Line Items]
Total floating rate debt		$ 253,424,000			100,000,000
Maximum facility capacity		$ 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
Master Repurchase Agreement | Weighted Average
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)		3.36%
Master Repurchase Agreement | Minimum | LIBOR
Debt Instrument [Line Items]
Credit facility, interest rate (as a percent)		2.50%
Master Repurchase Agreement | Maximum | LIBOR
Debt Instrument [Line Items]
Credit facility, interest rate (as a percent)		3.25%
FHLB Facility
Debt Instrument [Line Items]
Total floating rate debt		$ 45,750,000			0
Number of Federal Home Loan Bank Advances | advance		4
FHLB Facility | Minimum
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, weighted-average borrowing rate (as a percent)		0.50%
FHLB Facility | Maximum
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, weighted-average borrowing rate (as a percent)		0.58%
FHLB Advance Maturing in April 2016
Debt Instrument [Line Items]
Federal Home Loan Bank Advances outstanding		$ 1,000,000
FHLB Advance Maturing in April 2016, 2
Debt Instrument [Line Items]
Federal Home Loan Bank Advances outstanding		15,800,000
FHLB Advance Maturing in June 2016
Debt Instrument [Line Items]
Federal Home Loan Bank Advances outstanding		5,000,000
FHLB Advance Maturing in December 2016
Debt Instrument [Line Items]
Federal Home Loan Bank Advances outstanding		24,000,000
500 West Putnam Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 22,376,000			22,968,000
500 West Putnam Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		5.52%
Landmark Square
Debt Instrument [Line Items]
Total fixed rate debt		$ 79,562,000			81,269,000
Landmark Square | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		4.00%
485 Lexington Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 450,000,000			450,000,000
485 Lexington Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		5.61%
762 Madison Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 7,872,000			8,045,000
762 Madison Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		3.84%	3.86%	3.75%
885 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 267,650,000			267,650,000
885 Third Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		6.26%
1745 Broadway
Debt Instrument [Line Items]
Total fixed rate debt		$ 16,000,000			16,000,000
1745 Broadway | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		4.81%
388-390 Greenwich Street
Debt Instrument [Line Items]
Total fixed rate debt		$ 1,004,000,000			1,004,000,000
Total floating rate debt		$ 446,000,000			446,000,000
388-390 Greenwich Street | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		3.25%
Interest rate, floating rate debt (as a percent)		1.94%
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		$ 542,817,000			565,742,000
One Madison Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		5.91%
100 Church Street
Debt Instrument [Line Items]
Total fixed rate debt		$ 225,099,000			228,612,000
100 Church Street | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		4.68%
919 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 500,000,000			500,000,000
Interest in property (as a percent)		51.00%
919 Third Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		5.12%
400 East 57th Street
Debt Instrument [Line Items]
Total fixed rate debt		$ 67,644,000			68,896,000
400 East 57th Street | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		4.13%
400 East 58th Street
Debt Instrument [Line Items]
Total fixed rate debt		$ 28,990,000			29,527,000
400 East 58th Street | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		4.13%
420 Lexington Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 300,000,000			300,000,000
420 Lexington Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		3.99%
1515 Broadway
Debt Instrument [Line Items]
Total fixed rate debt		$ 900,000,000			900,000,000
1515 Broadway | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		3.93%
11 Madison Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 1,400,000,000			0
11 Madison Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)		3.84%
711 Third Avenue
Debt Instrument [Line Items]
Total fixed rate debt		$ 0			120,000,000
120 West 45th Street
Debt Instrument [Line Items]
Total fixed rate debt		0			170,000,000
600 Lexington Avenue
Debt Instrument [Line Items]
Total floating rate debt		$ 112,795,000			0
600 Lexington Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)		2.30%
187 Broadway & 5-7 Dey Street
Debt Instrument [Line Items]
Total floating rate debt		$ 40,000,000			0
187 Broadway & 5-7 Dey Street | Weighted Average
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)		2.85%
1080 Amsterdam
Debt Instrument [Line Items]
Total floating rate debt		$ 3,525,000			0
1080 Amsterdam | Weighted Average
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)		3.96%
248-252 Bedford Avenue
Debt Instrument [Line Items]
Total floating rate debt		$ 29,000,000			29,000,000
248-252 Bedford Avenue | Weighted Average
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)		1.69%
220 East 42nd Street
Debt Instrument [Line Items]
Total floating rate debt		$ 275,000,000			275,000,000
220 East 42nd Street | Weighted Average
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)		1.80%
180 Maiden Lane
Debt Instrument [Line Items]
Total floating rate debt		$ 0			$ 253,942,000

Corporate Indebtedness (Details

Corporate Indebtedness (Details) - USD ($)	1 Months Ended				12 Months Ended
	Jul. 31, 2015	Jan. 31, 2015	Nov. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Corporate Indebtedness
Increase in credit facility	$ 500,000,000
Outstanding under line of credit facility					$ 994,000,000	$ 385,000,000
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)					1.45%
Facility fee (as a percent)					0.25%
Outstanding under line of credit facility					$ 994,000,000
Revolving credit facility | Minimum
Corporate Indebtedness
Facility fee (as a percent)					0.125%
Revolving credit facility | Maximum
Corporate Indebtedness
Facility fee (as a percent)					0.30%
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%
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)					1.67%
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%
2012 Credit Facility
Corporate Indebtedness
Letters of credit					$ 73,100,000
Ability to borrow under line of credit facility					$ 532,900,000

Corporate Indebtedness (Senior

Corporate Indebtedness (Senior Unsecured Notes)(Details)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 06, 2010USD ($)$ / shares	Mar. 20, 2007$ / shares
Debt disclosures by scheduled maturity date
Accreted Balance	$ 2,319,244,000	$ 2,107,078,000
Senior unsecured notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	1,410,316,000
Accreted Balance	1,386,244,000	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	$ 255,296,000	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	$ 321,130,000	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)	12.3416
Principal amount of debentures, basis for conversion	$ 1,000
Amount of convertible debt recorded in equity			$ 78,300,000
Debt Instrument, Unamortized Discount	23,900,000
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	$ 249,810,000	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 | 4.27% Senior unsecured notes maturing on December 17, 2025
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	$ 100,000,000
Accreted Balance	$ 100,000,000	0
Coupon Rate (as a percent)	4.27%
Effective rate (as a percent)	4.27%
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 (Junior

Corporate Indebtedness (Junior Subordinated Deferrable Interest Debentures and Principal Maturities)(Details) - USD ($)	1 Months Ended	12 Months Ended
	Jun. 30, 2005	Dec. 31, 2015
Scheduled Amortization and Principal Repayments
2,016		$ 705,812,000
2,017		1,290,385,000
2,018		333,987,000
2,019		1,031,726,000
2,020		1,976,330,000
Thereafter		5,120,578,000
Total amortization of debt and principal repayments		10,458,818,000
Joint Venture Debt
Principal Repayments and Joint Venture Debt
2,016		529,646,000
2,017		615,085,000
2,018		2,195,000
2,019		104,687,000
2,020		30,298,000
Thereafter		451,544,000
Total principal repayments		$ 1,733,455,000
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
2,016		$ 0
2,017		0
2,018		0
2,019		0
2,020		0
Thereafter		100,000,000
Total amortization of debt and principal repayments		$ 100,000,000
Trust Preferred Securities | LIBOR
Debt Instrument [Line Items]
Interest rate added to base rate (as a percent)		1.25%
Mortgages and other loans payable
Scheduled Amortization
2,016		$ 51,018,000
2,017		63,829,000
2,018		64,462,000
2,019		70,409,000
2,020		52,799,000
Thereafter		147,604,000
Total amortization of debt		450,121,000
Principal Repayments and Joint Venture Debt
2,016		399,486,000
2,017		871,548,000
2,018		19,525,000
2,019		28,317,000
2,020		679,531,000
Thereafter		4,572,974,000
Total principal repayments		6,571,381,000
Revolving Credit Facility
Scheduled Amortization and Principal Repayments
2,016		0
2,017		0
2,018		0
2,019		0
2,020		994,000,000
Thereafter		0
Total amortization of debt and principal repayments		994,000,000
Unsecured Term Loan
Scheduled Amortization and Principal Repayments
2,016		0
2,017		0
2,018		0
2,019		933,000,000
2,020		0
Thereafter		0
Total amortization of debt and principal repayments		$ 933,000,000
Unsecured Term Loan | LIBOR
Debt Instrument [Line Items]
Interest rate added to base rate (as a percent)		1.40%
Senior Unsecured Notes
Scheduled Amortization and Principal Repayments
2,016		$ 255,308,000
2,017		355,008,000
2,018		250,000,000
2,019		0
2,020		250,000,000
Thereafter		300,000,000
Total amortization of debt and principal repayments		$ 1,410,316,000

Corporate Indebtedness (Schedul

Corporate Indebtedness (Schedule of Consolidated Interest Expense, Excluding Capitalized Interest)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest expense
Interest expense	$ 326,818	$ 319,898	$ 312,897
Interest income	(2,948)	(2,498)	(2,003)
Interest expense, net	323,870	317,400	310,894
Interest capitalized	$ 31,108	$ 22,750	$ 11,475

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amounts due from/to related parties
Due from joint ventures	$ 1,334	$ 1,254
Other	9,316	10,481
Related party receivables	10,650	11,735
Alliance Building Services
Related Party Transactions
Profit participation from related party	3,800	3,800	$ 3,500
Payments made for services	21,300	21,500	23,400
Entity with Stephen L Green ownership interest
Related Party Transactions
Property management fees from related party	$ 500	$ 400	$ 400

Noncontrolling Interests on t90

Noncontrolling Interests on the Company's Consolidated Financial Statements (Details)	1 Months Ended		12 Months Ended
	Feb. 28, 2015shares	Jan. 31, 2012$ / sharesshares	Dec. 31, 2015USD ($)unit$ / sharesshares	Dec. 31, 2014USD ($)unit	Dec. 31, 2013USD ($)	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 | $			(119,784,000)	$ (7,019,000)	$ (14,623,000)
Redemption of common units | $			(20,650,000)
Net income | $			10,565,000	18,467,000	3,023,000
Accumulated other comprehensive income allocation | $			(67,000)	175,000	611,000
Balance at end of period | $			$ 424,206,000	$ 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)			3.61%	3.92%
Number of units of operating partnership owned by the noncontrolling interest unit holders (shares) | unit			3,745,766	3,973,016
Shares of common stock reserved for issuance upon redemption of units of limited partnership interest in operating partnership (shares) | shares			3,745,766
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
Distributions | $			(9,710,000)	(7,849,000)
Issuance of common units | $			30,506,000	56,469,000
Redemption of common units | $			(55,697,000)	(31,653,000)
Net income | $			10,565,000	18,467,000
Accumulated other comprehensive income allocation | $			(67,000)	175,000
Fair value adjustment | $			(20,915,000)	168,439,000
Balance at end of period | $			$ 424,206,000	$ 469,524,000	$ 265,476,000
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
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
Mandatory liquidation preference (in dollars per share) | $			$ 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
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
Preferred Units, shares authorized | shares			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
Annual dividends on preferred units (in dollars per share)			$ 1
Preferred Units, shares authorized | shares			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
Annual dividends on preferred units (in dollars per share)			$ 0.9375
Preferred Units, shares authorized | shares			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
Annual dividends on preferred units (in dollars per share)			$ 0.75
Preferred Units, shares authorized | shares			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
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
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
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
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
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
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
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
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
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
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
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
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
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

Noncontrolling Interests on t91

Noncontrolling Interests on the Company's Consolidated Financial Statements - Preferred Unit Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 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	30,506	$ 56,469
Redemption of preferred units	(55,697)	(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 C92

Stockholders' Equity of the Company (Details) - $ / shares	Dec. 31, 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)	99,975,238
Excess shares issued (shares)	0

Stockholders' Equity of the C93

Stockholders' Equity of the Company (At-the-Market Equity Offering Program and Perpetual Preferred Stock)(Details) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Aug. 31, 2012	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 28, 2015	Jun. 30, 2014	Jul. 31, 2011
Stockholders' Equity
Proceeds from sale of common stock			$ 124,761,000	$ 185,321,000	$ 290,699,000
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	$ 250,000,000
Contributions - net proceeds from common stock offering (in shares)		895,956		25,659
Proceeds from sale of common stock		$ 113,400,000		$ 2,800,000
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	1,626,999
Proceeds from sale of common stock			$ 12,000,000	$ 182,900,000
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)			775,760	608	761
Proceeds from sale of common stock			$ 99,555,000	$ 63,720	$ 66,600
Common stock, shares authorized						3,500,000

Stockholders' Equity of the C94

Stockholders' Equity of the Company (Schedule of Common Stock Issued and Proceeds Received Dividend Reinvestments)(Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholders' Equity
Dividend reinvestments/stock purchases under the DRSPP	$ 124,761,000	$ 185,321,000	$ 290,699,000
Dividend Reinvestment and Stock Purchase Plan (DRIP)
Stockholders' Equity
Issuance of common stock (in shares)	775,760	608	761
Dividend reinvestments/stock purchases under the DRSPP	$ 99,555,000	$ 63,720	$ 66,600

Stockholders' Equity of the C95

Stockholders' Equity of the Company (Earnings per Share)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic Earnings:
Income attributable to SL Green common stockholders	$ 269,132	$ 503,104	$ 101,330
Diluted Earnings:
Income attributable to SL Green common stockholders	$ 279,697	$ 521,571	$ 104,353
Basic Shares:
Weighted average common shares outstanding (shares)	99,345,000	95,774,000	92,269,000
Effect of Dilutive Securities:
Redemption of units to common shares (shares)	3,899,000	3,514,000	2,735,000
Stock-based compensation plans (shares)	490,000	408,000	262,000
Diluted weighted average common stock outstanding (shares)	103,734,000	99,696,000	95,266,000
Common stock shares excluded from the diluted shares outstanding (shares)	263,991	737,361	964,789
Common Stock
Effect of Dilutive Securities:
Redemption of units to common shares	$ 10,565	$ 18,467	$ 3,023

Partners' Capital of the Oper96

Partners' Capital of the Operating Partnership (Details)	Dec. 31, 2015unitshares	Dec. 31, 2014unitshares	Dec. 31, 2013shares	Dec. 31, 2012shares
Common Stock
Stockholders' Equity
Units outstanding (units)	99,976,000	97,325,000	94,993,000	91,250,000
SL Green Operating Partnership
Stockholders' Equity
Noncontrolling interest in the operating partnership (as a percent)	3.61%	3.92%
Number of units of operating partnership owned by the noncontrolling interest unit holders (units) | unit	3,745,766	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)	99,975,238

Partners' Capital of the Oper97

Partners' Capital of the Operating Partnership - EPS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholders' Equity
Income attributable to SL Green common stockholders	$ 269,132	$ 503,104	$ 101,330
Weighted average common shares outstanding (shares)	99,345,000	95,774,000	92,269,000
Common stock shares excluded from the diluted shares outstanding (shares)	263,991	737,361	964,789
SL Green Operating Partnership
Stockholders' Equity
Income attributable to SL Green common stockholders	$ 279,697	$ 521,571	$ 104,353
Weighted average common shares outstanding (shares)	103,244,000	99,288,000	95,004,000
Stock-based compensation plans (shares)	490,000	408,000	262,000
Diluted weighted average common units outstanding (shares)	103,734,000	99,696,000	95,266,000
Common stock shares excluded from the diluted shares outstanding (shares)	263,991	737,361	964,789

Share-based Compensation - Addi

Share-based Compensation - Additional Information (Details)

1 Months Ended

12 Months Ended

Jan. 31, 2015USD ($)

Aug. 31, 2014shares

Aug. 31, 2011USD ($)

Dec. 31, 2015USD ($)unit / sharesfungible_unit$ / sharesshares

Dec. 31, 2014USD ($)shares

Dec. 31, 2013USD ($)shares

Sep. 30, 2014shares

Jun. 30, 2014shares

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

$ 6,500,000

$ 6,800,000

$ 4,500,000

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 9 months

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

3 years 5 months 19 days

Total unrecognized compensation cost related to unvested stock awards

$ 14,900,000

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

$ 9,522,613

2,841,678

18,041,576

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

$ 7,540,747

9,658,019

6,713,155

Total unrecognized compensation cost related to unvested stock awards

$ 21,000,000

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

2 years 8 months 12 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

1,600,000

Weighted average fair value of options granted during the period

$ 16,061,201

$ 1,141,675

$ 17,386,949

Awards granted (in shares) | shares

143,053

9,550

192,563

Awards outstanding (in shares) | shares

3,137,881

3,000,979

2,994,197

2,804,901

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

$ 2,000,000

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

1 year 4 months 21 days

Share-based Compensation

$ 30,200,000

31,400,000

$ 27,300,000

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

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

2.76

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

17,130,000

Fungible units | fungible_unit

1,100,000

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

$ 8,000,000

8,100,000

6,500,000

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

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

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

2,700,000

4,500,000

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

327,416

385,583

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

$ 4,500,000

8,600,000

$ 8,000,000

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

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

2011 Outperformance Plan | Earned anytime after beginning of second year

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

Percentage of units vested

33.33%

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

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

Percentage of units vested

66.67%

2011 Outperformance Plan | Vested on August 31, 2014

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

Percentage of units vested

50.00%

2011 Outperformance Plan | Vesting on August 31, 2015

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

Percentage of units vested

50.00%

2014 Outperformance Plan

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

Compensation expense

5,900,000

$ 200,000

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%

2014 Outperformance Plan | Vesting on August 31, 2017

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

Percentage of units vested

50.00%

2014 Outperformance Plan | Vesting on August 31, 2018

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

Percentage of units vested

50.00%

Deferred Stock Compensation Plan for Directors

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

Compensation expense

$ 1,900,000

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

100.00%

Awards granted (in shares) | shares

9,353

Shares issued (in shares) | shares

5,928

Awards outstanding (in shares) | shares

80,768

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%

Shares of common stock issued (shares) | shares

87,273

Share-based Compensation (Detai

Share-based Compensation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock options
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Dividend yield (as a percent)	1.97%	1.60%	1.92%
Expected life of option (in years)	3 years 7 months 6 days	3 years 7 months 6 days	4 years 1 month 6 days
Risk-free interest rate (as a percent)	1.43%	1.29%	0.96%
Expected stock price volatility (as a percent)	32.34%	33.97%	36.12%
Options Outstanding
Balance at beginning of year (in shares)	1,462,726	1,765,034	1,201,000
Granted (in shares)	389,836	102,050	828,100
Exercised (in shares)	(217,438)	(348,156)	(223,531)
Lapsed or cancelled (in shares)	(40,117)	(56,202)	(40,535)
Balance at end of period (in shares)	1,595,007	1,462,726	1,765,034
Options exercisable at end of period (in shares)	589,055	428,951	461,458
Weighted average fair value of options granted during the period	$ 9,522,613	$ 2,841,678	$ 18,041,576
Weighted Average Exercise Price
Balance at beginning of year (in dollars per share)	$ 87.98	$ 83.24	$ 75.05
Granted (in dollars per share)	112.54	119.12	87.23
Exercised (in dollars per share)	74.69	72.76	53.93
Lapsed or cancelled (in dollars per share)	98.61	90.03	83.94
Balance at end of period (in dollars per share)	95.52	87.98	83.24
Options exercisable at end of period (in dollars per share)	$ 89.85	$ 90.32	$ 89.38
Restricted Stock Awards
Options Outstanding
Weighted average fair value of options granted during the period	$ 16,061,201	$ 1,141,675	$ 17,386,949
Summary of restricted stock
Balance at beginning of year (in shares)	3,000,979	2,994,197	2,804,901
Granted (in shares)	143,053	9,550	192,563
Cancelled (in shares)	(6,151)	(2,768)	(3,267)
Balance at end of period (in shares)	3,137,881	3,000,979	2,994,197
Vested during the period (in shares)	87,081	75,043	21,074
Compensation expense recorded	$ 7,540,747	$ 9,658,019	$ 6,713,155

Accumulated Other Comprehens100

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	$ (6,980)
Ending Balance	(8,749)	$ (6,980)
SL Green Realty Corp
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	(6,980)	(15,211)	$ (29,587)
Other comprehensive (loss) income before reclassifications	(13,467)	(421)	7,573
Amounts reclassified from accumulated other comprehensive income	11,698	8,652	6,803
Ending Balance	(8,749)	(6,980)	(15,211)
Deferred net losses from terminated hedges	9,700	11,800
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)	(15,125)	(16,834)
Other comprehensive (loss) income before reclassifications	(11,143)	(576)	(168)
Amounts reclassified from accumulated other comprehensive income	10,481	6,203	1,877
Ending Balance	(10,160)	(9,498)	(15,125)
SL Green Realty Corp | Unrealized gain (loss) on marketable securities
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	2,613	4,784	3,310
Other comprehensive (loss) income before reclassifications	(610)	(2,692)	1,474
Amounts reclassified from accumulated other comprehensive income	0	521	0
Ending Balance	2,003	2,613	4,784
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)	(4,870)	(16,063)
Other comprehensive (loss) income before reclassifications	(1,714)	2,847	6,267
Amounts reclassified from accumulated other comprehensive income	1,217	1,928	4,926
Ending Balance	$ (592)	$ (95)	$ (4,870)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value of Financial Instruments
Marketable securities	$ 45,138	$ 39,429
Interest rate cap and swap agreements (included in other assets)	204	2,174
Interest rate cap swap agreements (included in accrued interest payable and other liabilities)	10,776	14,728
Debt and preferred equity investments	1,670,020	1,408,804
Secured Debt, Bearing Variable Interest, Amount	1,205,494	1,103,942
248-252 Bedford Avenue
Fair Value of Financial Instruments
Secured Debt, Bearing Variable Interest, Amount	29,000	29,000
248-252 Bedford Avenue | Liabilities Held for Sale
Fair Value of Financial Instruments
Secured Debt, Bearing Variable Interest, Amount	29,000
180 Maiden Lane
Fair Value of Financial Instruments
Secured Debt, Bearing Variable Interest, Amount	0	253,942
180 Maiden Lane | Liabilities Held for Sale
Fair Value of Financial Instruments
Secured Debt, Bearing Variable Interest, Amount		253,900
Carrying Value
Fair Value of Financial Instruments
Fixed rate debt	7,232,254	6,140,786
Variable rate debt	3,202,494	2,291,943
Total	10,434,748	8,432,729
Fair Value
Fair Value of Financial Instruments
Marketable securities	45,138	39,429
Total	10,770,574	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	1,800,000	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)	204	2,174
Interest rate cap swap agreements (included in accrued interest payable and other liabilities)	10,776	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	1,670,020	1,408,804
Level 3 | Fair Value
Fair Value of Financial Instruments
Fixed rate debt	7,591,388	6,565,236
Variable rate debt	3,179,186	2,315,952
Equity marketable securities
Fair Value of Financial Instruments
Marketable securities	4,704	4,332
Equity marketable securities | Level 1
Fair Value of Financial Instruments
Marketable securities	4,704	4,332
Mortgage-backed securities
Fair Value of Financial Instruments
Marketable securities	40,434	35,097
Mortgage-backed securities | Level 2
Fair Value of Financial Instruments
Marketable securities	$ 40,434	$ 35,097

Financial Instruments_ Deriv102

Financial Instruments: Derivatives and Hedging (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financial Instruments: Derivatives and Hedging
Fair Value	$ (10,776)	$ (14,728)
Fair Value	204	2,174
Derivative, Fair Value, Net	(10,572)
Gain (loss) from settlement of hedges included in accumulated other comprehensive loss (less than)	15,000	61,000	$ 16,000
Fair value of derivatives in a net liability position	11,300
Aggregate termination value	11,300
Estimated current balance held in accumulated other comprehensive loss to be reclassified into earnings within the next 12 months	5,500
Share of joint venture of accumulated other comprehensive loss reclassified into equity in net income from unconsolidated joint ventures within the next 12 months	700
Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion)	(13,386)	2,213	6,485
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	12,157	8,430	7,005
Amount of (Loss) or Gain Recognized into Income (Ineffective Portion)	(441)	4	3
Joint venture
Financial Instruments: Derivatives and Hedging
Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion)	(1,779)	2,916	6,553
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	1,265	1,999	5,072
Amount of (Loss) or Gain Recognized into Income (Ineffective Portion)	(19)	0	0
Interest Rate Cap- Sold Expiring in May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 504,000
Strike Rate (as a percent)	4.75%
Fair Value	$ 0
Interest Rate Cap Expiring in May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 504,000
Strike Rate (as a percent)	4.75%
Fair Value	$ 0
Interest Rate Cap Expiring In May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 500,000
Strike Rate (as a percent)	4.75%
Fair Value	$ 0
Interest Rate Cap- Sold Expiring in May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 500,000
Strike Rate (as a percent)	4.75%
Fair Value	$ 0
Interest Rate Cap Expiring In May 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 446,000
Strike Rate (as a percent)	4.75%
Fair Value	$ 0
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 200,000
Strike Rate (as a percent)	0.9375%
Fair Value	$ 71
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000
Strike Rate (as a percent)	0.94%
Fair Value	$ 47
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000
Strike Rate (as a percent)	0.94%
Fair Value	$ 47
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 144,000
Strike Rate (as a percent)	2.236%
Fair Value	$ (3,516)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 86,400
Strike Rate (as a percent)	1.9475%
Fair Value	$ (1,630)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,000
Strike Rate (as a percent)	2.31%
Fair Value	$ (1,862)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,000
Strike Rate (as a percent)	1.345%
Fair Value	$ (522)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,000
Strike Rate (as a percent)	2.31%
Fair Value	$ (1,859)
Interest Rate Swap Expiring in December 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 57,600
Strike Rate (as a percent)	1.99%
Fair Value	$ (1,134)
Interest Rate Swap Expiring in June 2016
Financial Instruments: Derivatives and Hedging
Notional Value	$ 30,000
Strike Rate (as a percent)	2.295%
Fair Value	$ (241)
Interest Rate Swap Expiring in January 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 14,409
Strike Rate (as a percent)	0.50%
Fair Value	$ 36
Interest Rate Swap Expiring in February 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 8,018
Strike Rate (as a percent)	0.852%
Fair Value	$ (12)
Interest Rate Cap Expiring in September 2017
Financial Instruments: Derivatives and Hedging
Notional Value	$ 137,500
Strike Rate (as a percent)	4.00%
Fair Value	$ 3
Interest Rate Swap
Financial Instruments: Derivatives and Hedging
Amount of (Loss) Gain Recognized in Other Comprehensive Loss (Effective Portion)	(11,607)	(703)	(68)
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)	10,892	6,431	1,933
Amount of (Loss) or Gain Recognized into Income (Ineffective Portion)	$ (422)	$ 4	$ 3

Rental Income (Details)

Rental Income (Details) $ in Thousands	Dec. 31, 2015USD ($)
Consolidated properties
Operating Leased Assets [Line Items]
2,016	$ 1,181,279
2,017	1,162,046
2,018	1,087,356
2,019	996,282
2,020	940,948
Thereafter	6,780,451
Total minimum lease payments	12,148,362
Unconsolidated properties
Operating Leased Assets [Line Items]
2,016	175,027
2,017	181,804
2,018	177,630
2,019	167,695
2,020	158,575
Thereafter	958,010
Total minimum lease payments	$ 1,818,741

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2000
Multiemployer Plans [Line Items]
Plan contributions	$ 17,184		$ 17,115		$ 17,293
401 (K) Plan
Employee contribution limit per calendar year (percentage)	15.00%
Employer match of employee contributions of first specified percentage of annual compensation (percentage)	50.00%		50.00%		50.00%		50.00%
Percentage of eligible compensation matched by employer (percentage)	6.00%		6.00%		6.00%		4.00%
Matching contribution	$ 550		$ 550		$ 550
Health Plan
Multiemployer Plans [Line Items]
Plan contributions		$ 1,087,200		$ 1,037,400		$ 923,500
Contributions by company (less than) (percentage)	5.00%
Health Plan
Multiemployer Plans [Line Items]
Plan contributions	$ 8,736		8,470		8,522
Other plans
Multiemployer Plans [Line Items]
Plan contributions	5,716		5,838		6,006
Pension Plan
Multiemployer Plans [Line Items]
Plan contributions	$ 2,732		$ 2,807		$ 2,765
Pension Plan
Multiemployer Plans [Line Items]
Surcharges	No
Plan contributions		$ 221,900		$ 226,700		$ 242,300

Commitments and Contingencie105

Commitments and Contingencies (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2013extenstion_option	Oct. 31, 2012USD ($)	Dec. 31, 2015USD ($)portfolioextenstion_optionpolicy	Dec. 31, 2014USD ($)
Other Commitments [Line Items]
Employment agreements with certain executives, minimum cash-based compensation for next fiscal year			$ 5,000
Employment agreements with certain executives, grant date value of deferred compensation awards			$ 1,500
Number of property insurance portfolios for which all-risk property and rental value coverage is maintained (portfolio) | portfolio			3
Capital lease obligations			$ 41,360	$ 20,822
Cost basis			$ 47,445	27,445
Initial term of non cancellable operating leases, minimum (in years)			1 year
Capital lease
2,016			$ 2,266
2,017			2,387
2,018			2,387
2,019			2,411
2,020			2,620
Thereafter			825,483
Total minimum lease payments			837,554
Less amount representing interest			(796,194)
Capital lease obligations			41,360
Non-cancellable operating leases
2,016			30,816
2,017			31,049
2,018			31,049
2,019			31,066
2,020			31,436
Thereafter			764,352
Total minimum lease payments			$ 919,768
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
420 Lexington Avenue
Other Commitments [Line Items]
Land as percentage of fair market value of property under lease			6.00%
Number of renewal options available (extension option) | extenstion_option	2
Annual ground lease payments through December 2019			$ 10,900
Annual ground lease payments through December 2029			11,200
Annual ground lease payments due thereafter			12,300
1080 Amsterdam Avenue
Other Commitments [Line Items]
Prepayment of ground lease rent		$ 13,000
Cost basis			27,400
Cumulative amortization			$ 400
711 Third Avenue
Other Commitments [Line Items]
Percentage of the fee not owned by the entity (percent)			50.00%
711 Third Avenue | Through July 2016
Other Commitments [Line Items]
Required annual ground lease payments			$ 5,250
711 Third Avenue | After July 2016
Other Commitments [Line Items]
Required annual ground lease payments			$ 5,500
461 Fifth Avenue
Other Commitments [Line Items]
Number of renewal options available (extension option) | extenstion_option			2
Required annual ground lease payments			$ 2,100
Term of first renewal option (in years)			21 years
Term of second renewal option (in years)			21 years
Term of third renewal option (in years)			15 years
625 Madison Avenue
Other Commitments [Line Items]
Number of renewal options available (extension option) | extenstion_option			2
Required annual ground lease payments			$ 4,600
Term of first renewal option (in years)			23 years
Term of second renewal option (in years)			23 years
1185 Avenue of the Americas
Other Commitments [Line Items]
Required annual ground lease payments			$ 6,900
Term of first renewal option (in years)			23 years
Belmont
Other Commitments [Line Items]
Loss reserves			$ 6,400	$ 6,100
TRIPRA 2,015
Other Commitments [Line Items]
Program trigger			100,000
Per annum increase			20,000
Property and rental value coverage
Other Commitments [Line Items]
Blanket limit per occurrence maintained under first property portfolio			950,000
Blanket limit per occurrence maintained under second property portfolio			1,500,000
Amount of flood coverage			100,000
Blanket limit per occurrence maintained under third property portfolio			$ 380,000
Number of liability policies which cover all properties and provide limits of $201.0 million per occurrence and in the aggregate per location | policy			2
Limit per occurrence and in aggregate per location under liability policies			$ 201,000

Segment Information (Details)

Segment Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)segment	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Segment information
Number of reportable segments (segment) | segment	2
Total revenues	$ 1,662,829	$ 1,519,978	$ 1,371,065
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 depreciable real estate reserves	90,240	173,030	109,400
Total assets	$ 19,857,941	17,096,587
Leverage rate assumption (as a percent)	100.00%
Marketing, general and administrative	$ 94,873	92,488	86,192
Operating Segments | Real Estate Segment
Segment information
Total revenues	1,481,701	1,341,163	1,177,222
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 depreciable real estate reserves	(63,345)	22,178	(49,793)
Total assets	18,175,665	15,671,662
Operating Segments | Debt and Preferred Equity Segment
Segment information
Total revenues	181,128	178,815	193,843
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 depreciable real estate reserves	153,585	150,852	$ 159,193
Total assets	$ 1,682,276	$ 1,424,925

Segment Information (Schedule o

Segment Information (Schedule of Reconciliation of Income from Continuing Operations to Net Income Attributable to SL Green Common Stockholders)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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 depreciable real estate reserves	$ 90,240	$ 173,030	$ 109,400
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Purchase price fair value adjustment	40,078	67,446	(2,305)
Gain on sale of real estate, net	175,974	0	0
Depreciable real estate reserves	(19,226)	0	0
Income from continuing operations	302,910	363,729	110,696
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Net income	$ 317,459	$ 545,863	$ 151,283

Quarterly Financial Data of 108

Quarterly Financial Data of the Company (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Total revenues									$ 1,662,829	$ 1,519,978	$ 1,371,065
Income (loss) from continuing operations before equity in net income from unconsolidated joint ventures, equity in net (loss) 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 gain (loss) on early extinguishment of debt									77,261	174,963	118,062
Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate									15,844	123,253	3,601
Purchase price fair value adjustment									38,563	65,059	(2,239)
Gain on sale of real estate, net									175,974	0	0
Depreciable real estate reserves									(19,226)	0	0
(Loss) gain on early extinguishment of debt									(49)	(32,365)	(18,518)
Gain on sale of investment in marketable securities									0	3,895	(65)
Net income from discontinued operations									427	19,075	25,687
Gain on sale of discontinued operations									14,122	163,059	14,900
Net income (loss) attributable to SL Green/SLGOP									284,084	518,056	135,371
Perpetual preferred stock dividends									(14,952)	(14,952)	(21,881)
Net income attributable to SL Green common stockholders									$ 269,132	$ 503,104	$ 101,330
Net income (loss) attributable to common stockholders per common share - basic (usd per share)									$ 2.71	$ 5.25	$ 1.10
Net income (loss) attributable to common stockholders per common share - diluted (usd per share)									$ 2.70	$ 5.23	$ 1.10
SL Green Realty Corp
Condensed Income Statements, Captions [Line Items]
Total revenues	$ 425,390	$ 432,066	$ 409,074	$ 396,299	$ 386,627	$ 390,274	$ 380,631	$ 362,446
Income (loss) from continuing operations before equity in net income from unconsolidated joint ventures, equity in net (loss) 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 gain (loss) on early extinguishment of debt	47,760	11,637	(36,137)	33,654	40,379	46,863	47,035	39,416
Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate	(206)	15,281	769	0	673	16,496	1,444	104,640
Purchase price fair value adjustment	40,078	0	0	0	0	(4,000)	71,446	0
Gain on sale of real estate, net	16,270	159,704	0	0
Depreciable real estate reserves	0	(19,226)	0	0
(Loss) gain on early extinguishment of debt	0	0	0	(49)	(6,865)	(24,475)	(1,028)	3
Gain on sale of investment in marketable securities					3,895	0	0	0
Net income from discontinued operations	0	0	0	427	3,626	4,035	5,645	5,769
Gain on sale of discontinued operations	1,139	0	0	12,983	18,817	29,507	114,735	0
Net income (loss) attributable to SL Green/SLGOP	105,041	167,396	(35,368)	47,015	60,525	68,426	239,277	149,828
Perpetual preferred stock dividends	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)
Net income attributable to SL Green common stockholders	$ 101,303	$ 163,658	$ (39,106)	$ 43,277	$ 56,787	$ 64,688	$ 235,539	$ 146,090
Net income (loss) attributable to common stockholders per common share - basic (usd per share)	$ 1.02	$ 1.64	$ (0.39)	$ 0.44	$ 0.59	$ 0.68	$ 2.47	$ 1.54
Net income (loss) attributable to common stockholders per common share - diluted (usd per share)	$ 1.01	$ 1.64	$ (0.39)	$ 0.44	$ 0.59	$ 0.68	$ 2.46	$ 1.53

Quarterly Financial Data of 109

Quarterly Financial Data of the Operating Partnership (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Total revenues									$ 1,662,829	$ 1,519,978	$ 1,371,065
Income (loss) from continuing operations before equity in net income from unconsolidated joint ventures, equity in net (loss) 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 gain (loss) on early extinguishment of debt									77,261	174,963	118,062
Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate									15,844	123,253	3,601
Purchase price fair value adjustment									38,563	65,059	(2,239)
Gain on sale of real estate									175,974	0	0
Depreciable real estate reserves									(19,226)	0	0
Gain (loss) on early extinguishment of debt									(49)	(32,365)	(18,518)
Gain on sale of investment in marketable securities									0	3,895	(65)
Net income from discontinued operations									427	19,075	25,687
Gain on sale of discontinued operations									14,122	163,059	14,900
Net income (loss) attributable to SL Green/SLGOP									284,084	518,056	135,371
SL Green Operating Partnership
Condensed Income Statements, Captions [Line Items]
Total revenues	$ 425,390	$ 432,066	$ 409,074	$ 396,299	$ 386,627	$ 390,274	$ 380,631	$ 362,446	1,662,829	1,519,978	1,371,065
Income (loss) from continuing operations before equity in net income from unconsolidated joint ventures, equity in net (loss) 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 gain (loss) on early extinguishment of debt	51,691	18,104	(37,714)	35,397	42,837	49,499	55,680	44,144	77,261	174,963	118,062
Equity in net (loss) gain on sale of interest in unconsolidated joint venture/real estate	(206)	15,281	769	0	673	16,496	1,444	104,640	15,844	123,253	3,601
Purchase price fair value adjustment	40,078	0	0	0	0	(4,000)	71,446	0	40,078	67,446	(2,305)
Gain on sale of real estate	16,270	159,704	0	0					175,974	0	0
Depreciable real estate reserves	0	(19,226)	0	0					(19,226)	0	0
Gain (loss) on early extinguishment of debt	0	0	0	(49)	(6,865)	(24,475)	(1,028)	3	(49)	(32,365)	(18,518)
Gain on sale of investment in marketable securities					3,895	0	0	0	0	3,895	(65)
Net income from discontinued operations	0	0	0	427	3,626	4,035	5,645	5,769	427	19,075	25,687
Gain on sale of discontinued operations	1,139	0	0	12,983	18,817	29,507	114,735	0	14,122	163,059	14,900
Net income (loss) attributable to SL Green/SLGOP	108,972	173,863	(36,945)	48,758	62,983	71,062	247,922	154,556	294,649	536,523	138,394
Perpetual preferred distributions	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(3,738)	(14,952)	(14,952)	(21,881)
Net income attributable to SLGOP common unitholders	$ 105,234	$ 170,125	$ (40,683)	$ 45,020	$ 59,245	$ 67,324	$ 244,184	$ 150,818	$ 279,697	$ 521,571	$ 104,353
Net income attributable to common unitholders per common unit - basic (usd per share)	$ 1.02	$ 1.64	$ (0.39)	$ 0.44	$ 0.59	$ 0.68	$ 2.47	$ 1.54	$ 2.71	$ 5.25	$ 1.10
Net income attributable to common unitholders per common share - diluted (usd per share)	$ 1.01	$ 1.64	$ (0.39)	$ 0.44	$ 0.59	$ 0.68	$ 2.46	$ 1.53	$ 2.70	$ 5.23	$ 1.10

Schedule II - Valuation and 110

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tenant and other receivables—allowance
Changes in valuation allowance
Balance at Beginning of Year	$ 18,068	$ 17,325	$ 14,341
Additions Charged Against Operations	8,139	13,533	13,425
Uncollectible Accounts Written-off/Recovery	(8,589)	(12,790)	(10,441)
Balance at End of Year	17,618	18,068	17,325
Deferred rent receivable—allowance
Changes in valuation allowance
Balance at Beginning of Year	27,411	30,333	29,580
Additions Charged Against Operations	2,789	4,140	7,563
Uncollectible Accounts Written-off/Recovery	(8,470)	(7,062)	(6,810)
Balance at End of Year	$ 21,730	$ 27,411	$ 30,333

Schedule III - Real Estate A111

Schedule III - Real Estate And Accumulated Depreciation (Details) - USD ($) $ in Thousands	1 Months Ended
	May. 31, 2010	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 6,702,330
Initial Cost
Land		4,803,542
Building & Improvements		10,994,972
Cost Capitalized Subsequent To Acquisition
Land		(24,384)
Building & Improvements		907,472
Gross Amount at Which Carried at Close of Period
Land		4,779,158
Building & Improvements		11,902,444
Total		16,681,602	$ 14,069,141	$ 12,333,780	$ 11,662,953
Accumulated Depreciation		2,060,706	$ 1,905,165	$ 1,646,240	$ 1,393,323
420 Lexington Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		300,000
Initial Cost
Land		0
Building & Improvements		107,832
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		233,845
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		341,677
Total		341,677
Accumulated Depreciation		123,717
711 Third Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		19,844
Building & Improvements		42,499
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		38,618
Gross Amount at Which Carried at Close of Period
Land		19,844
Building & Improvements		81,117
Total		100,961
Accumulated Depreciation		$ 29,741
Interest in property (as a percent)		50.00%
555 W. 57th Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		18,846
Building & Improvements		78,704
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		50,261
Gross Amount at Which Carried at Close of Period
Land		18,846
Building & Improvements		128,965
Total		147,811
Accumulated Depreciation		53,036
317 Madison Ave
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		21,205
Building & Improvements		85,559
Cost Capitalized Subsequent To Acquisition
Land		(21,205)
Building & Improvements		(85,559)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		0
220 East 42nd Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		275,000
Initial Cost
Land		50,373
Building & Improvements		203,727
Cost Capitalized Subsequent To Acquisition
Land		635
Building & Improvements		64,648
Gross Amount at Which Carried at Close of Period
Land		51,008
Building & Improvements		268,375
Total		319,383
Accumulated Depreciation		90,072
461 Fifth Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		0
Building & Improvements		62,695
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		11,527
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		74,222
Total		74,222
Accumulated Depreciation		24,449
750 Third Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		51,093
Building & Improvements		205,972
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		37,283
Gross Amount at Which Carried at Close of Period
Land		51,093
Building & Improvements		243,255
Total		294,348
Accumulated Depreciation		78,460
625 Madison Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		0
Building & Improvements		246,673
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		38,779
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		285,452
Total		285,452
Accumulated Depreciation		87,625
485 Lexington Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		450,000
Initial Cost
Land		77,517
Building & Improvements		326,825
Cost Capitalized Subsequent To Acquisition
Land		765
Building & Improvements		88,570
Gross Amount at Which Carried at Close of Period
Land		78,282
Building & Improvements		415,395
Total		493,677
Accumulated Depreciation		140,556
609 Fifth Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		36,677
Building & Improvements		145,954
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		8,157
Gross Amount at Which Carried at Close of Period
Land		36,677
Building & Improvements		154,111
Total		190,788
Accumulated Depreciation		37,473
120 West 45th Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		60,766
Building & Improvements		250,922
Cost Capitalized Subsequent To Acquisition
Land		(60,766)
Building & Improvements		(250,922)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		0
810 Seventh Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		114,077
Building & Improvements		476,386
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		65,604
Gross Amount at Which Carried at Close of Period
Land		114,077
Building & Improvements		541,990
Total		656,067
Accumulated Depreciation		131,946
919 Third Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		500,000
Initial Cost
Land		223,529
Building & Improvements		1,033,198
Cost Capitalized Subsequent To Acquisition
Land		35,410
Building & Improvements		27,639
Gross Amount at Which Carried at Close of Period
Land		258,939
Building & Improvements		1,060,837
Total		1,319,776
Accumulated Depreciation		$ 245,932
Interest in property (as a percent)		51.00%
1185 Avenue of the Americas
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		0
Building & Improvements		728,213
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		36,857
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		765,070
Total		765,070
Accumulated Depreciation		198,483
1350 Avenue of the Americas
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		91,038
Building & Improvements		380,744
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		32,612
Gross Amount at Which Carried at Close of Period
Land		91,038
Building & Improvements		413,356
Total		504,394
Accumulated Depreciation		102,335
1100 King Street - 1 to 7 International Drive
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		49,392
Building & Improvements		104,376
Cost Capitalized Subsequent To Acquisition
Land		2,473
Building & Improvements		17,612
Gross Amount at Which Carried at Close of Period
Land		51,865
Building & Improvements		121,988
Total		173,853
Accumulated Depreciation		31,007
520 White Plains Road
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		6,324
Building & Improvements		26,096
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		6,720
Gross Amount at Which Carried at Close of Period
Land		6,324
Building & Improvements		32,816
Total		39,140
Accumulated Depreciation		8,617
115-117 Stevens Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		5,933
Building & Improvements		23,826
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		5,797
Gross Amount at Which Carried at Close of Period
Land		5,933
Building & Improvements		29,623
Total		35,556
Accumulated Depreciation		7,916
100 Summit Lake Drive
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		10,526
Building & Improvements		43,109
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		7,402
Gross Amount at Which Carried at Close of Period
Land		10,526
Building & Improvements		50,511
Total		61,037
Accumulated Depreciation		13,567
200 Summit Lake Drive
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		11,183
Building & Improvements		47,906
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		8,223
Gross Amount at Which Carried at Close of Period
Land		11,183
Building & Improvements		56,129
Total		67,312
Accumulated Depreciation		14,714
500 Summit Lake Drive
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		9,777
Building & Improvements		39,048
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		5,456
Gross Amount at Which Carried at Close of Period
Land		9,777
Building & Improvements		44,504
Total		54,281
Accumulated Depreciation		10,557
140 Grand Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		6,865
Building & Improvements		28,264
Cost Capitalized Subsequent To Acquisition
Land		(6,865)
Building & Improvements		(28,264)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		0
360 Hamilton Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		29,497
Building & Improvements		118,250
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		12,515
Gross Amount at Which Carried at Close of Period
Land		29,497
Building & Improvements		130,765
Total		160,262
Accumulated Depreciation		31,927
1-6 Landmark Square
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		79,562
Initial Cost
Land		50,947
Building & Improvements		195,167
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		36,803
Gross Amount at Which Carried at Close of Period
Land		50,947
Building & Improvements		231,970
Total		282,917
Accumulated Depreciation		54,477
7 Landmark Square
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		2,088
Building & Improvements		7,748
Cost Capitalized Subsequent To Acquisition
Land		(367)
Building & Improvements		84
Gross Amount at Which Carried at Close of Period
Land		1,721
Building & Improvements		7,832
Total		9,553
Accumulated Depreciation		799
680 Washington Boulevard
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		11,696
Building & Improvements		45,364
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		5,818
Gross Amount at Which Carried at Close of Period
Land		11,696
Building & Improvements		51,182
Total		62,878
Accumulated Depreciation		12,783
750 Washington Boulevard
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		16,916
Building & Improvements		68,849
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		6,459
Gross Amount at Which Carried at Close of Period
Land		16,916
Building & Improvements		75,308
Total		92,224
Accumulated Depreciation		17,391
1010 Washington Boulevard
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		7,747
Building & Improvements		30,423
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		5,223
Gross Amount at Which Carried at Close of Period
Land		7,747
Building & Improvements		35,646
Total		43,393
Accumulated Depreciation		8,732
500 West Putnam Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		22,376
Initial Cost
Land		11,210
Building & Improvements		44,782
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		5,054
Gross Amount at Which Carried at Close of Period
Land		11,210
Building & Improvements		49,836
Total		61,046
Accumulated Depreciation		11,684
150 Grand Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		1,371
Building & Improvements		5,446
Cost Capitalized Subsequent To Acquisition
Land		(1,371)
Building & Improvements		(5,446)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		0
400 Summit Lake Drive
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		38,889
Building & Improvements		1
Cost Capitalized Subsequent To Acquisition
Land		285
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		39,174
Building & Improvements		1
Total		39,175
Accumulated Depreciation		1
331 Madison Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		14,763
Building & Improvements		65,241
Cost Capitalized Subsequent To Acquisition
Land		(14,763)
Building & Improvements		(65,241)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		0
1055 Washington Boulevard
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		13,516
Building & Improvements		53,228
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		5,297
Gross Amount at Which Carried at Close of Period
Land		13,516
Building & Improvements		58,525
Total		72,041
Accumulated Depreciation		13,747
1 Madison Ave
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		542,817
Initial Cost
Land		172,641
Building & Improvements		654,394
Cost Capitalized Subsequent To Acquisition
Land		905
Building & Improvements		15,261
Gross Amount at Which Carried at Close of Period
Land		173,546
Building & Improvements		669,655
Total		843,201
Accumulated Depreciation		141,854
125 Chubb Way
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		5,884
Building & Improvements		25,958
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		24,482
Gross Amount at Which Carried at Close of Period
Land		5,884
Building & Improvements		50,440
Total		56,324
Accumulated Depreciation		7,200
100 Church Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		225,099
Initial Cost
Land		32,494
Building & Improvements		79,996
Cost Capitalized Subsequent To Acquisition
Land		2,500
Building & Improvements		87,286
Gross Amount at Which Carried at Close of Period
Land		34,994
Building & Improvements		167,282
Total		202,276
Accumulated Depreciation		33,564
125 Park Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		120,900
Building & Improvements		189,714
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		55,365
Gross Amount at Which Carried at Close of Period
Land		120,900
Building & Improvements		245,079
Total		365,979
Accumulated Depreciation		43,887
885 Third Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		267,650
Initial Cost
Land		131,766
Building & Improvements		0
Cost Capitalized Subsequent To Acquisition
Land		110,771
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		242,537
Building & Improvements		0
Total		242,537
Accumulated Depreciation		0
Williamsburg
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		3,677
Building & Improvements		14,708
Cost Capitalized Subsequent To Acquisition
Land		2,523
Building & Improvements		(4,550)
Gross Amount at Which Carried at Close of Period
Land		6,200
Building & Improvements		10,158
Total		16,358
Accumulated Depreciation		1,343
1515 Broadway
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		900,000
Initial Cost
Land		462,700
Building & Improvements		707,938
Cost Capitalized Subsequent To Acquisition
Land		1,145
Building & Improvements		102,335
Gross Amount at Which Carried at Close of Period
Land		463,845
Building & Improvements		810,273
Total		1,274,118
Accumulated Depreciation		112,497
110 East 42nd Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		34,000
Building & Improvements		46,411
Cost Capitalized Subsequent To Acquisition
Land		2,354
Building & Improvements		19,165
Gross Amount at Which Carried at Close of Period
Land		36,354
Building & Improvements		65,576
Total		101,930
Accumulated Depreciation		12,397
51 East 42nd Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		44,095
Building & Improvements		33,470
Cost Capitalized Subsequent To Acquisition
Land		(44,095)
Building & Improvements		(33,470)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		0
400 East 57th Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		67,644
Initial Cost
Land		39,780
Building & Improvements		69,895
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		14,136
Gross Amount at Which Carried at Close of Period
Land		39,780
Building & Improvements		84,031
Total		123,811
Accumulated Depreciation		$ 7,534
Interest in property (as a percent)		90.00%
400 East 58th Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 28,990
Initial Cost
Land		17,549
Building & Improvements		30,916
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		6,217
Gross Amount at Which Carried at Close of Period
Land		17,549
Building & Improvements		37,133
Total		54,682
Accumulated Depreciation		$ 3,291
Interest in property (as a percent)		90.00%
752 Madison Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		282,415
Building & Improvements		7,131
Cost Capitalized Subsequent To Acquisition
Land		1,871
Building & Improvements		10
Gross Amount at Which Carried at Close of Period
Land		284,286
Building & Improvements		7,141
Total		291,427
Accumulated Depreciation		$ 858
Interest in property (as a percent)		80.00%
762 Madison Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 7,872
Initial Cost
Land		6,153
Building & Improvements		10,461
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		90
Gross Amount at Which Carried at Close of Period
Land		6,153
Building & Improvements		10,551
Total		16,704
Accumulated Depreciation		$ 1,083
Interest in property (as a percent)		90.00%
19-21 East 65th Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		0
Building & Improvements		7,389
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		159
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		7,548
Total		7,548
Accumulated Depreciation		$ 753
Interest in property (as a percent)		90.00%
304 Park Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		54,189
Building & Improvements		75,619
Cost Capitalized Subsequent To Acquisition
Land		300
Building & Improvements		8,122
Gross Amount at Which Carried at Close of Period
Land		54,489
Building & Improvements		83,741
Total		138,230
Accumulated Depreciation		10,341
635 Sixth Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		24,180
Building & Improvements		37,158
Cost Capitalized Subsequent To Acquisition
Land		163
Building & Improvements		49,534
Gross Amount at Which Carried at Close of Period
Land		24,343
Building & Improvements		86,692
Total		111,035
Accumulated Depreciation		1,462
641 Sixth Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		45,668
Building & Improvements		67,316
Cost Capitalized Subsequent To Acquisition
Land		308
Building & Improvements		1,888
Gross Amount at Which Carried at Close of Period
Land		45,976
Building & Improvements		69,204
Total		115,180
Accumulated Depreciation		7,308
1080 Amsterdam
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		3,525
Initial Cost
Land		0
Building & Improvements		27,445
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		20,405
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		47,850
Total		47,850
Accumulated Depreciation		$ 1,766
Interest in property (as a percent)		92.50%
131-137 Spring Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		27,021
Building & Improvements		105,342
Cost Capitalized Subsequent To Acquisition
Land		(27,021)
Building & Improvements		(105,342)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		0
Total		0
Accumulated Depreciation		$ 0
Interest in property (as a percent)		20.00%
248-252 Bedford Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 29,000
Initial Cost
Land		10,865
Building & Improvements		44,035
Cost Capitalized Subsequent To Acquisition
Land		(10,865)
Building & Improvements		(43,672)
Gross Amount at Which Carried at Close of Period
Land		0
Building & Improvements		363
Total		363
Accumulated Depreciation		$ 0
Interest in property (as a percent)		90.00%
16 Court
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		19,217
Building & Improvements		63,210
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		10,854
Gross Amount at Which Carried at Close of Period
Land		19,217
Building & Improvements		74,064
Total		93,281
Accumulated Depreciation		7,393
315 West 33rd Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		195,834
Building & Improvements		164,429
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		6,173
Gross Amount at Which Carried at Close of Period
Land		195,834
Building & Improvements		170,602
Total		366,436
Accumulated Depreciation		10,246
562 Fifth Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		57,052
Building & Improvements		$ 10,487
Cost Capitalized Subsequent To Acquisition
Land
Building & Improvements		$ 1,213
Gross Amount at Which Carried at Close of Period
Land		57,052
Building & Improvements		11,700
Total		68,752
Accumulated Depreciation		1,874
388-390 Greenwich Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		1,450,000
Initial Cost
Land		516,292
Building & Improvements		964,434
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		140,275
Gross Amount at Which Carried at Close of Period
Land		516,292
Building & Improvements		1,104,709
Total		1,621,001
Accumulated Depreciation		48,195
719 Seventh Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		41,850
Building & Improvements		0
Cost Capitalized Subsequent To Acquisition
Land		500
Building & Improvements		6,107
Gross Amount at Which Carried at Close of Period
Land		42,350
Building & Improvements		6,107
Total		48,457
Accumulated Depreciation		$ 0
Interest in property (as a percent)		75.00%
115 Spring Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		11,078
Building & Improvements		44,799
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		247
Gross Amount at Which Carried at Close of Period
Land		11,078
Building & Improvements		45,046
Total		56,124
Accumulated Depreciation		1,788
635 Madison Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		205,632
Building & Improvements		15,805
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		205,632
Building & Improvements		15,805
Total		221,437
Accumulated Depreciation		515
102 Greene Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		8,215
Building & Improvements		26,717
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		277
Gross Amount at Which Carried at Close of Period
Land		8,215
Building & Improvements		26,994
Total		35,209
Accumulated Depreciation		847
1640 Flatbush Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		6,120
Building & Improvements		680
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		6,120
Building & Improvements		680
Total		6,800
Accumulated Depreciation		13
One Vanderbilt
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		80,069
Building & Improvements		116,557
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		31,095
Gross Amount at Which Carried at Close of Period
Land		80,069
Building & Improvements		147,652
Total		227,721
Accumulated Depreciation		0
Upper East Side Residential
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		17,500
Building & Improvements		32,500
Cost Capitalized Subsequent To Acquisition
Land		26
Building & Improvements		48
Gross Amount at Which Carried at Close of Period
Land		17,526
Building & Improvements		32,548
Total		50,074
Accumulated Depreciation		$ 450
Interest in property (as a percent)		90.00%
110 Greene Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 0
Initial Cost
Land		89,250
Building & Improvements		165,750
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		324
Gross Amount at Which Carried at Close of Period
Land		89,250
Building & Improvements		166,074
Total		255,324
Accumulated Depreciation		$ 1,827
Interest in property (as a percent)		90.00%
11 Madison Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 1,400,000
Initial Cost
Land		849,926
Building & Improvements		1,579,118
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		66,007
Gross Amount at Which Carried at Close of Period
Land		849,926
Building & Improvements		1,645,125
Total		2,495,051
Accumulated Depreciation		11,020
187 Broadway
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		8,400
Initial Cost
Land		4,707
Building & Improvements		8,741
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		4,707
Building & Improvements		8,741
Total		13,448
Accumulated Depreciation		799
5- 7 Dey Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		31,600
Initial Cost
Land		17,394
Building & Improvements		32,304
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		17,394
Building & Improvements		32,304
Total		49,698
Accumulated Depreciation		2,953
30 East 40th Street
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		4,650
Building & Improvements		20,000
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		4,650
Building & Improvements		20,000
Total		24,650
Accumulated Depreciation		82
600 Lexington Avenue
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		112,795
Initial Cost
Land		97,044
Building & Improvements		180,224
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		97,044
Building & Improvements		180,224
Total		277,268
Accumulated Depreciation		$ 288
Ownership interest acquired (percent)	55.00%
Acquisition Price	$ 193,000
Ownership interest in consolidated joint venture (as a percent)		45.00%
Value of interest		$ 277,300
Other
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		0
Initial Cost
Land		2,130
Building & Improvements		10,894
Cost Capitalized Subsequent To Acquisition
Land		0
Building & Improvements		0
Gross Amount at Which Carried at Close of Period
Land		2,130
Building & Improvements		10,894
Total		13,024
Accumulated Depreciation		$ 3,534

Schedule III - Real Estate A112

Schedule III - Real Estate And Accumulated Depreciation (Activity in Real Estate and Accumulated Depreciation)(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in real estate
Balance at beginning of year	$ 14,069,141	$ 12,333,780	$ 11,662,953
Property acquisitions	3,064,137	2,428,259	702,717
Improvements	396,555	379,295	199,141
Retirements/disposals/deconsolidation	(848,231)	(1,072,193)	(231,031)
Balance at end of year	16,681,602	14,069,141	12,333,780
Aggregate cost of land, buildings and improvements before depreciation	12,400,000
Changes in accumulated depreciation
Balance at beginning of year	1,905,165	1,646,240	1,393,323
Depreciation for year	480,523	307,823	286,776
Retirements/disposals/deconsolidation	(324,982)	(48,898)	(33,859)
Balance at end of year	$ 2,060,706	$ 1,905,165	$ 1,646,240