SL Green Realty (SLG) 10-Q 3 May 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	May 02, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	1-13199
Entity Registrant Name	SL GREEN REALTY CORP
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	13-3956775
Entity Address, Address Line One	One Vanderbilt Avenue
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10017
City Area Code	212
Local Phone Number	594-2700
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		64,805,769
Entity Central Index Key	0001040971
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false
Common Stock
Document Information [Line Items]
Trading Symbol	SLG
Title of 12(b) Security	Common Stock, $0.01 par value
Security Exchange Name	NYSE
Preferred stock
Document Information [Line Items]
Trading Symbol	SLG.PRI
Title of 12(b) Security	6.500% Series I Cumulative Redeemable Preferred Stock, $0.01 par value
Security Exchange Name	NYSE
SL Green Operating Partnership
Document Information [Line Items]
Entity File Number	33-167793-02
Entity Registrant Name	SL GREEN OPERATING PARTNERSHIP, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3960938
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		306,110
Entity Central Index Key	0001492869
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Commercial real estate properties, at cost:
Land and land interests		$ 1,150,681	$ 1,092,671
Building and improvements		3,729,884	3,655,624
Building leasehold and improvements		1,358,851	1,354,569
Right of use asset - operating leases		953,236	953,236
Total commercial real estate properties, at cost		7,192,652	7,056,100
Less: accumulated depreciation		(2,078,203)	(2,035,311)
Total commercial real estate properties, net		5,114,449	5,020,789
Assets held for sale		21,586	0
Cash and cash equivalents		196,035	221,823
Restricted cash		122,461	113,696
Investments in marketable securities		10,673	9,591
Tenant and other receivables		38,659	33,270
Related party receivables		12,229	12,168
Deferred rents receivable		267,969	264,653
Debt and preferred equity investments, net of discounts and deferred origination fees of $1,623 and $1,630 and allowances of $13,520 and $13,520 in 2024 and 2023, respectively		352,347	346,745
Investments in unconsolidated joint ventures		2,984,786	2,983,313
Deferred costs, net		109,296	111,463
Other assets		533,802	413,670
Total assets	[1]	9,764,292	9,531,181
Liabilities
Mortgages and other loans payable, net		1,695,163	1,491,319
Revolving credit facility, net		645,138	554,752
Unsecured term loans, net		1,245,382	1,244,881
Unsecured notes, net		99,820	99,795
Accrued interest payable		23,217	17,930
Other liabilities		437,302	471,401
Accounts payable and accrued expenses		101,495	153,164
Deferred revenue		157,756	134,053
Lease liability - financing leases		105,859	105,531
Lease liability - operating leases		823,594	827,692
Dividend and distributions payable		20,135	20,280
Security deposits		56,398	49,906
Liabilities related to assets held for sale		10,649	0
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities		100,000	100,000
Total liabilities	[1]	5,521,908	5,270,704
Commitments and contingencies
Noncontrolling interests in Operating Partnership		272,235	238,051
Preferred units		166,501	166,501
Equity
Series I Preferred Stock, $0.01 par value, $25.00 liquidation preference, 9,200 issued and outstanding at both March 31, 2024 and December 31, 2023		221,932	221,932
Common stock, $0.01 par value, 160,000 shares authorized and 65,866 and 65,786 issued and outstanding at March 31, 2024 and December 31, 2023, respectively (including 1,060 and 1,060 shares held in treasury at March 31, 2024 and December 31, 2023, respectively)		660	660
Additional paid-in-capital		3,831,130	3,826,452
Treasury stock at cost		(128,655)	(128,655)
Accumulated other comprehensive income		40,151	17,477
Retained deficit		(229,607)	(151,551)
Total SL Green stockholders' equity		3,735,611	3,786,315
Noncontrolling interests in other partnerships		68,037	69,610
Total equity		3,803,648	3,855,925
Total liabilities and equity		$ 9,764,292	$ 9,531,181
[1] (1) The Company's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $120.4 million and $41.2 million of land, $81.3 million and $40.5 million of building and improvements, $— million and $— million of building and leasehold improvements, $— million and $— million of right of use assets, $5.7 million and $5.4 million of accumulated depreciation, $785.1 million and $676.9 million of other assets included in other line items, $254.3 million and $50.0 million of real estate debt, net, $2.7 million and $0.9 million of accrued interest payable, $— million and $— million of lease liabilities, and $332.5 million and $306.5 million of other liabilities included in other line items as of March 31, 2024 and December 31, 2023, respectively.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets
Debt and preferred equity investments, discount and deferred origination fees	$ 1,623	$ 1,630
Allowance for loan and lease losses, real estate	$ 13,520	$ 13,520
Equity
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 (in shares)	160,000,000	160,000,000
Common stock, shares issued (in shares)	65,866,000	65,786,000
Common stock, shares outstanding (in shares)	65,866,000	65,786,000
Treasury stock, shares (in shares)	1,060,000	1,060,000
Land and land interests	$ 1,150,681	$ 1,092,671
Building and improvements	3,729,884	3,655,624
Building leasehold and improvements	1,358,851	1,354,569
Right of use asset - operating leases	953,236	953,236
Accumulated depreciation	2,078,203	2,035,311
Other assets	533,802	413,670
Mortgages and other loans payable, net	1,695,163	1,491,319
Lease liability - financing leases	105,859	105,531
Other liabilities	437,302	471,401
Service Corporation
Equity
Land and land interests	120,400	41,200
Building and improvements	81,300	40,500
Building leasehold and improvements	0	0
Right of use asset - operating leases	0	0
Accumulated depreciation	5,700	5,400
Other assets	785,100	676,900
Mortgages and other loans payable, net	254,300	50,000
Accrued interest payable	2,700	900
Lease liability - financing leases	0	0
Other liabilities	$ 332,500	$ 306,500
Series I Preferred Stock
Equity
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 (in shares)	9,200,000	9,200,000
Preferred stock, shares outstanding (in shares)	9,200,000	9,200,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Rental revenue, net	$ 141,504	$ 195,042
SUMMIT Operator revenue	25,604	19,771
Investment income	7,403	9,057
Other income	13,371	21,894
Total revenues	187,882	245,764
Expenses
Operating expenses, including related party expenses of $0 in 2024, and $1 in 2023	43,608	52,064
Real estate taxes	31,606	41,383
Operating lease rent	6,405	6,301
SUMMIT Operator expenses	21,858	20,688
Interest expense, net of interest income	31,173	41,653
Amortization of deferred financing costs	1,539	2,021
SUMMIT Operator tax (benefit) expense	(1,295)	1,267
Depreciation and amortization	48,584	78,782
Loan loss and other investment reserves, net of recoveries	0	6,890
Transaction related costs	16	884
Marketing, general and administrative	21,313	23,285
Total expenses	204,807	275,218
Equity in net income (loss) from unconsolidated joint ventures	111,160	(7,412)
Equity in net gain (loss) on sale of interest in unconsolidated joint venture/real estate	26,764	(79)
Purchase price and other fair value adjustments	(50,492)	239
Loss on sale of real estate, net	0	(1,651)
Depreciable real estate reserves and impairment	(52,118)	0
Income from continuing operations	18,389	(38,357)
Net income (loss)	18,389	(38,357)
Net loss attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(901)	2,337
Noncontrolling interests in other partnerships	1,294	1,625
Preferred units distributions	(1,903)	(1,598)
Net income (loss) attributable to SL Green	16,879	(35,993)
Perpetual preferred stock dividends	(3,738)	(3,738)
Net income (loss) attributable to SL Green common stockholders	$ 13,141	$ (39,731)
Basic earnings (loss) per share (in dollars per share)	$ 0.20	$ (0.63)
Diluted earnings (loss) per share (in dollars per share)	$ 0.20	$ (0.63)
Basic weighted average common shares outstanding (in shares)	64,328	64,079
Diluted weighted average common shares and common share equivalents outstanding (in shares)	70,095	68,182

Consolidated Statements of Op_2

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Expenses
Operating expenses	$ 43,608	$ 52,064
Related party
Expenses
Operating expenses	$ 0	$ 1

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 18,389	$ (38,357)
Other comprehensive income (loss):
Increase (decrease) in unrealized value of derivative instruments, including SL Green's share of joint venture derivative instruments	23,214	(31,059)
Increase (decrease) in unrealized value of marketable securities	1,082	(968)
Other comprehensive income (loss)	24,296	(32,027)
Comprehensive income (loss)	42,685	(70,384)
Net (income) loss attributable to noncontrolling interests and preferred units distributions	(1,510)	2,364
Other comprehensive (income) loss attributable to noncontrolling interests	(1,622)	1,851
Comprehensive income (loss) attributable to SL Green	$ 39,553	$ (66,169)

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid- In-Capital	Treasury Stock	Accumulated Other Comprehensive Income	Retained Deficit	Noncontrolling Interests	Series I Preferred Stock Series I Preferred Stock
Beginning balance at Dec. 31, 2022	$ 4,646,922	$ 656	$ 3,790,358	$ (128,655)	$ 49,604	$ 651,138	$ 61,889	$ 221,932
Beginning balance (in shares) at Dec. 31, 2022		64,380
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(37,618)					(35,993)	(1,625)
Other comprehensive income	(30,176)				(30,176)
Perpetual preferred stock dividends	(3,738)					(3,738)
DRSPP proceeds (in shares)		5
DRSPP proceeds	184		184
Reallocation of noncontrolling interest in the Operating Partnership	(10,147)					(10,147)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)		(12)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	7,559		7,559
Contributions to consolidated joint venture interests	8,560						8,560
Cash distributions to noncontrolling interests	(136)						(136)
Cash distributions declared	(52,236)					(52,236)
Ending balance at Mar. 31, 2023	4,529,174	$ 656	3,798,101	(128,655)	19,428	549,024	68,688	221,932
Ending balance (in shares) at Mar. 31, 2023		64,373
Beginning balance at Dec. 31, 2023	3,855,925	$ 660	3,826,452	(128,655)	17,477	(151,551)	69,610	221,932
Beginning balance (in shares) at Dec. 31, 2023		64,726
Increase (Decrease) in Stockholders' Equity
Net income (loss)	15,585					16,879	(1,294)
Acquisition of subsidiary interest	(5,674)						(5,674)
Other comprehensive income	22,674				22,674
Perpetual preferred stock dividends	(3,738)					(3,738)
DRSPP proceeds (in shares)		2
DRSPP proceeds	77		77
Reallocation of noncontrolling interest in the Operating Partnership	(42,841)					(42,841)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)		78
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	4,601		4,601
Contributions to consolidated joint venture interests	6,678						6,678
Cash distributions to noncontrolling interests	(1,283)						(1,283)
Cash distributions declared	(48,356)					(48,356)
Ending balance at Mar. 31, 2024	$ 3,803,648	$ 660	$ 3,831,130	$ (128,655)	$ 40,151	$ (229,607)	$ 68,037	$ 221,932
Ending balance (in shares) at Mar. 31, 2024		64,806

Consolidated Statements of Eq_2

Consolidated Statements of Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Cash distributions declared (per common unit, none of which represented a return of capital for federal income tax purposes) (in dollars per share)	$ 0.750	$ 0.812

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating Activities
Net income (loss)	$ 18,389	$ (38,357)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	50,123	80,803
Equity in net (income) loss from unconsolidated joint ventures	(111,160)	7,412
Distributions of cumulative earnings from unconsolidated joint ventures	68	258
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(26,764)	79
Purchase price and other fair value adjustments	50,492	(239)
Depreciable real estate reserves and impairment	52,118	0
Loss on sale of real estate, net	0	1,651
Loan loss reserves and other investment reserves, net of recoveries	0	6,890
Deferred rents receivable	(3,721)	(7,431)
Non-cash lease expense	5,003	5,261
Other non-cash adjustments	11,166	(3,271)
Changes in operating assets and liabilities:
Tenant and other receivables	(3,174)	(969)
Related party receivables	245	577
Deferred lease costs	(3,735)	(3,911)
Other assets	(12,644)	(11,394)
Accounts payable, accrued expenses, other liabilities and security deposits	(50,003)	4,656
Deferred revenue	3,017	2,450
Lease liability - operating leases	(4,097)	(2,116)
Net cash (used in) provided by operating activities	(24,677)	42,349
Investing Activities
Additions to land, buildings and improvements	(55,316)	(61,918)
Acquisition deposits and deferred purchase price	(12,817)	0
Investments in unconsolidated joint ventures	(23,830)	(22,985)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	71,545	41,812
Net proceeds from disposition of real estate/joint venture interest	26,420	0
Other investments	(2,770)	(17,700)
Origination of debt and preferred equity investments	(6,945)	(5,578)
Net cash used in investing activities	(3,713)	(66,369)
Financing Activities
Proceeds from mortgages and other loans payable	493	0
Repayments of mortgages and other loans payable	(1,501)	(1,473)
Proceeds from revolving credit facility, term loans and unsecured notes	130,000	143,000
Repayments of revolving credit facility, term loans and unsecured notes	(40,000)	(78,000)
Proceeds from stock options exercised and DRSPP issuance	77	184
Redemption of OP units	(18,608)	(5,220)
Distributions to noncontrolling interests in other partnerships	(1,283)	(136)
Contributions from noncontrolling interests in other partnerships	0	426
Distributions to noncontrolling interests in the Operating Partnership	(3,609)	(3,822)
Dividends paid on common and preferred stock	(54,142)	(57,373)
Deferred loan costs	(60)	(358)
Net cash provided by (used in) financing activities	11,367	(2,772)
Net decrease in cash, cash equivalents, and restricted cash	(17,023)	(26,792)
Cash, cash equivalents, and restricted cash at beginning of year	335,519	384,054
Cash, cash equivalents, and restricted cash at end of period	318,496	357,262
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Fair value adjustment to noncontrolling interest in the Operating Partnership	42,841	10,147
Consolidation of a subsidiary	6,678	0
Consolidation of mortgage loan payable	205,000	0
Acquisition of subsidiary interest from noncontrolling interest	5,674	0
Contribution to consolidated joint venture interest	0	8,134
Removal of fully depreciated commercial real estate properties	3,354	4,247
Share repurchase or redemption payable	5,012	0
Cash and cash equivalents	196,035	158,937
Restricted cash	122,461	198,325
Total cash, cash equivalents, and restricted cash	$ 318,496	$ 357,262

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Partnership) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Commercial real estate properties, at cost:
Land and land interests		$ 1,150,681	$ 1,092,671
Building and improvements		3,729,884	3,655,624
Building leasehold and improvements		1,358,851	1,354,569
Right of use asset - operating leases		953,236	953,236
Total commercial real estate properties, at cost		7,192,652	7,056,100
Less: accumulated depreciation		(2,078,203)	(2,035,311)
Total commercial real estate properties, net		5,114,449	5,020,789
Assets held for sale		21,586	0
Cash and cash equivalents		196,035	221,823
Restricted cash		122,461	113,696
Investments in marketable securities		10,673	9,591
Tenant and other receivables		38,659	33,270
Related party receivables		12,229	12,168
Deferred rents receivable		267,969	264,653
Debt and preferred equity investments, net of discounts and deferred origination fees of $1,623 and $1,630 and allowances of $13,520 and $13,520 in 2024 and 2023, respectively		352,347	346,745
Investments in unconsolidated joint ventures		2,984,786	2,983,313
Deferred costs, net		109,296	111,463
Other assets		533,802	413,670
Total assets	[1]	9,764,292	9,531,181
Liabilities
Mortgages and other loans payable, net		1,695,163	1,491,319
Revolving credit facility, net		645,138	554,752
Unsecured term loans, net		1,245,382	1,244,881
Unsecured notes, net		99,820	99,795
Accrued interest payable		23,217	17,930
Other liabilities		437,302	471,401
Accounts payable and accrued expenses		101,495	153,164
Deferred revenue		157,756	134,053
Lease liability - financing leases		105,859	105,531
Lease liability - operating leases		823,594	827,692
Dividend and distributions payable		20,135	20,280
Security deposits		56,398	49,906
Liabilities related to assets held for sale		10,649	0
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities		100,000	100,000
Total liabilities	[1]	5,521,908	5,270,704
Commitments and contingencies
Preferred units		166,501	166,501
SLGOP partners' capital:
Accumulated other comprehensive income		40,151	17,477
Total liabilities and equity		9,764,292	9,531,181
SL Green Operating Partnership
Commercial real estate properties, at cost:
Land and land interests		1,150,681	1,092,671
Building and improvements		3,729,884	3,655,624
Building leasehold and improvements		1,358,851	1,354,569
Right of use asset - operating leases		953,236	953,236
Total commercial real estate properties, at cost		7,192,652	7,056,100
Less: accumulated depreciation		(2,078,203)	(2,035,311)
Total commercial real estate properties, net		5,114,449	5,020,789
Assets held for sale		21,586	0
Cash and cash equivalents		196,035	221,823
Restricted cash		122,461	113,696
Investments in marketable securities		10,673	9,591
Tenant and other receivables		38,659	33,270
Related party receivables		12,229	12,168
Deferred rents receivable		267,969	264,653
Debt and preferred equity investments, net of discounts and deferred origination fees of $1,623 and $1,630 and allowances of $13,520 and $13,520 in 2024 and 2023, respectively		352,347	346,745
Investments in unconsolidated joint ventures		2,984,786	2,983,313
Deferred costs, net		109,296	111,463
Other assets		533,802	413,670
Total assets	[2]	9,764,292	9,531,181
Liabilities
Mortgages and other loans payable, net		1,695,163	1,491,319
Revolving credit facility, net		645,138	554,752
Unsecured term loans, net		1,245,382	1,244,881
Unsecured notes, net		99,820	99,795
Accrued interest payable		23,217	17,930
Other liabilities		437,302	471,401
Accounts payable and accrued expenses		101,495	153,164
Deferred revenue		157,756	134,053
Lease liability - financing leases		105,859	105,531
Lease liability - operating leases		823,594	827,692
Dividend and distributions payable		20,135	20,280
Security deposits		56,398	49,906
Liabilities related to assets held for sale		10,649	0
Junior subordinated deferrable interest debentures held by trusts that issued trust preferred securities		100,000	100,000
Total liabilities	[2]	5,521,908	5,270,704
Commitments and contingencies
Limited partner interests in SLGOP (4,417 and 3,949 limited partner common units outstanding at March 31, 2024 and December 31, 2023, respectively)		272,235	238,051
Preferred units		166,501	166,501
SLGOP partners' capital:
Series I Preferred Units, $25.00 liquidation preference, 9,200 issued and outstanding at both March 31, 2024 and December 31, 2023		221,932	221,932
SL Green partners' capital (692 and 687 general partner common units and 64,114 and 64,039 limited partner common units outstanding at March 31, 2024 and December 31, 2023, respectively)		3,473,528	3,546,906
Accumulated other comprehensive income		40,151	17,477
Total SLGOP partners' capital		3,735,611	3,786,315
Noncontrolling interests in other partnerships		68,037	69,610
Total capital		3,803,648	3,855,925
Total liabilities and equity		$ 9,764,292	$ 9,531,181
[1] (1) The Company's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $120.4 million and $41.2 million of land, $81.3 million and $40.5 million of building and improvements, $— million and $— million of building and leasehold improvements, $— million and $— million of right of use assets, $5.7 million and $5.4 million of accumulated depreciation, $785.1 million and $676.9 million of other assets included in other line items, $254.3 million and $50.0 million of real estate debt, net, $2.7 million and $0.9 million of accrued interest payable, $— million and $— million of lease liabilities, and $332.5 million and $306.5 million of other liabilities included in other line items as of March 31, 2024 and December 31, 2023, respectively. (1) The Operating Partnership's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $120.4 million and $41.2 million of land, $81.3 million and $40.5 million of building and improvements, $— million and $— million of building and leasehold improvements, $— million and $— million of right of use assets, $5.7 million and $5.4 million of accumulated depreciation, $785.1 million and $676.9 million of other assets included in other line items, $254.3 million and $50.0 million of real estate debt, net, $2.7 million and $0.9 million of accrued interest payable, $— million and $— million of lease liabilities, and $332.5 million and $306.5 million of other liabilities included in other line items as of March 31, 2024 and December 31, 2023, respectively.

Consolidated Balance Sheets (_3

Consolidated Balance Sheets (Partnership) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets
Debt and preferred equity investments, discount and deferred origination fees	$ 1,623	$ 1,630
Allowance for loan and lease losses, real estate	13,520	13,520
SLGOP partners' capital:
Land and land interests	1,150,681	1,092,671
Building and improvements	3,729,884	3,655,624
Building leasehold and improvements	1,358,851	1,354,569
Right of use asset - operating leases	953,236	953,236
Accumulated depreciation	2,078,203	2,035,311
Other assets	533,802	413,670
Mortgages and other loans payable, net	1,695,163	1,491,319
Lease liability - financing leases	105,859	105,531
Other liabilities	437,302	471,401
SL Green Operating Partnership
Assets
Debt and preferred equity investments, discount and deferred origination fees	1,623	1,630
Allowance for loan and lease losses, real estate	$ 13,520	$ 13,520
Liabilities
Limited partner interests in Operating Partnership, limited partner common units outstanding (shares)	4,417	3,949
SLGOP partners' capital:
SL Green partner's capital, general partner common units outstanding (shares)	692	687
SL Green partners' capital, limited partner common units outstanding (shares)	64,114	64,039
Land and land interests	$ 1,150,681	$ 1,092,671
Building and improvements	3,729,884	3,655,624
Building leasehold and improvements	1,358,851	1,354,569
Right of use asset - operating leases	953,236	953,236
Accumulated depreciation	2,078,203	2,035,311
Other assets	533,802	413,670
Mortgages and other loans payable, net	1,695,163	1,491,319
Lease liability - financing leases	105,859	105,531
Other liabilities	437,302	471,401
Service Corporation
SLGOP partners' capital:
Land and land interests	120,400	41,200
Building and improvements	81,300	40,500
Building leasehold and improvements	0	0
Right of use asset - operating leases	0	0
Accumulated depreciation	5,700	5,400
Other assets	785,100	676,900
Mortgages and other loans payable, net	254,300	50,000
Accrued interest payable	2,700	900
Lease liability - financing leases	0	0
Other liabilities	$ 332,500	$ 306,500
Series I Preferred Stock | SL Green Operating Partnership
SLGOP partners' capital:
Preferred units, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred units, shares issued (in shares)	9,200	9,200
Preferred units, shares outstanding (in shares)	9,200	9,200

Consolidated Statements of Op_3

Consolidated Statements of Operations (Partnership) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Rental revenue, net	$ 141,504	$ 195,042
SUMMIT Operator revenue	25,604	19,771
Investment income	7,403	9,057
Other income	13,371	21,894
Total revenues	187,882	245,764
Expenses
Operating expenses	43,608	52,064
Real estate taxes	31,606	41,383
Operating lease rent	6,405	6,301
SUMMIT Operator expenses	21,858	20,688
Interest expense, net of interest income	31,173	41,653
Amortization of deferred financing costs	1,539	2,021
SUMMIT Operator tax (benefit) expense	(1,295)	1,267
Depreciation and amortization	48,584	78,782
Loan loss and other investment reserves, net of recoveries	0	6,890
Transaction related costs	16	884
Marketing, general and administrative	21,313	23,285
Total expenses	204,807	275,218
Equity in net income (loss) from unconsolidated joint ventures	111,160	(7,412)
Equity in net gain (loss) on sale of interest in unconsolidated joint venture/real estate	26,764	(79)
Purchase price and other fair value adjustments	(50,492)	239
Loss on sale of real estate, net	0	(1,651)
Depreciable real estate reserves and impairment	(52,118)	0
Net income (loss)	18,389	(38,357)
Net loss attributable to noncontrolling interests:
Noncontrolling interests in other partnerships	1,294	1,625
Preferred units distributions	(1,903)	(1,598)
Net income (loss) attributable to SL Green	16,879	(35,993)
Perpetual preferred stock dividends	(3,738)	(3,738)
SL Green Operating Partnership
Revenues
Rental revenue, net	141,504	195,042
SUMMIT Operator revenue	25,604	19,771
Investment income	7,403	9,057
Other income	13,371	21,894
Total revenues	187,882	245,764
Expenses
Operating expenses	43,608	52,064
Real estate taxes	31,606	41,383
Operating lease rent	6,405	6,301
SUMMIT Operator expenses	21,858	20,688
Interest expense, net of interest income	31,173	41,653
Amortization of deferred financing costs	1,539	2,021
SUMMIT Operator tax (benefit) expense	(1,295)	1,267
Depreciation and amortization	48,584	78,782
Loan loss and other investment reserves, net of recoveries	0	6,890
Transaction related costs	16	884
Marketing, general and administrative	21,313	23,285
Total expenses	204,807	275,218
Equity in net income (loss) from unconsolidated joint ventures	111,160	(7,412)
Equity in net gain (loss) on sale of interest in unconsolidated joint venture/real estate	26,764	(79)
Purchase price and other fair value adjustments	(50,492)	239
Loss on sale of real estate, net	0	(1,651)
Depreciable real estate reserves and impairment	(52,118)	0
Net income (loss)	18,389	(38,357)
Net loss attributable to noncontrolling interests:
Noncontrolling interests in other partnerships	1,294	1,625
Preferred units distributions	(1,903)	(1,598)
Net income (loss) attributable to SL Green	17,780	(38,330)
Perpetual preferred stock dividends	(3,738)	(3,738)
Net income (loss) attributable to SLGOP common unitholders	$ 14,042	$ (42,068)
Basic earnings (loss) per unit (in dollars per share)	$ 0.20	$ (0.63)
Diluted earnings (loss) per unit (in dollars per share)	$ 0.20	$ (0.63)
Basic weighted average common units outstanding (in shares)	68,767	68,182
Diluted weighted average common units and common unit equivalents outstanding (in shares)	70,095	68,182

Consolidated Statements of Op_4

Consolidated Statements of Operations (Partnership) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Expenses
Operating expenses	$ 43,608	$ 52,064
Related party
Expenses
Operating expenses	0	1
SL Green Operating Partnership
Expenses
Operating expenses	43,608	52,064
SL Green Operating Partnership | Related party
Expenses
Operating expenses	$ 0	$ 1

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive (Loss) Income (Partnership) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net income (loss)	$ 18,389	$ (38,357)
Other comprehensive income (loss):
Increase (decrease) in unrealized value of derivative instruments, including SL Green's share of joint venture derivative instruments	23,214	(31,059)
Increase (decrease) in unrealized value of marketable securities	1,082	(968)
Other comprehensive income (loss)	24,296	(32,027)
Comprehensive income (loss)	42,685	(70,384)
Net loss attributable to noncontrolling interests	1,294	1,625
Other comprehensive (income) loss attributable to noncontrolling interests	(1,622)	1,851
Comprehensive income (loss) attributable to SL Green	39,553	(66,169)
SL Green Operating Partnership
Net income (loss)	18,389	(38,357)
Other comprehensive income (loss):
Increase (decrease) in unrealized value of derivative instruments, including SL Green's share of joint venture derivative instruments	23,214	(31,059)
Increase (decrease) in unrealized value of marketable securities	1,082	(968)
Other comprehensive income (loss)	24,296	(32,027)
Comprehensive income (loss)	42,685	(70,384)
Net loss attributable to noncontrolling interests	1,294	1,625
Other comprehensive (income) loss attributable to noncontrolling interests	(1,622)	1,851
Comprehensive income (loss) attributable to SL Green	$ 42,357	$ (66,908)

Consolidated Statements of Capi

Consolidated Statements of Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Increase (Decrease) in Partner's Capital
Redemption and conversion of common units	$ (5,674)
DRSPP proceeds	77	$ 184
Reallocation of noncontrolling interest in the Operating Partnership	(42,841)	(10,147)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	4,601	7,559
Contributions to consolidated joint venture interests	6,678	8,560
Cash distributions to noncontrolling interests	$ (1,283)	$ (136)
Common Stock
Increase (Decrease) in Partner's Capital
DRSPP proceeds (in shares)	2	5
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	78	(12)
Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Redemption and conversion of common units	$ (5,674)
Contributions to consolidated joint venture interests	6,678	$ 8,560
Cash distributions to noncontrolling interests	(1,283)	(136)
SL Green Operating Partnership
Increase (Decrease) in Partner's Capital
Beginning balance	3,855,925	4,646,922
Net income (loss)	15,585	(37,618)
Redemption and conversion of common units	(5,674)
Other comprehensive income	22,674	(30,176)
Perpetual preferred unit dividends	(3,738)	(3,738)
DRSPP proceeds	77	184
Reallocation of noncontrolling interest in the Operating Partnership	(42,841)	(10,147)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	4,601	7,559
Contributions to consolidated joint venture interests		8,560
Cash distributions to noncontrolling interests	(1,283)	(136)
Cash distributions declared	(48,356)	(52,236)
Ending balance	3,803,648	4,529,174
SL Green Operating Partnership | Preferred stock | Series I Preferred Stock
Increase (Decrease) in Partner's Capital
Beginning balance	221,932	221,932
Ending balance	221,932	221,932
SL Green Operating Partnership | Common Stock | Partners' Interest
Increase (Decrease) in Partner's Capital
Beginning balance	$ 3,546,906	$ 4,313,497
Beginning balance (units)	64,726	64,380
Net income (loss)	$ 16,879	$ (35,993)
Perpetual preferred unit dividends	$ (3,738)	$ (3,738)
DRSPP proceeds (in shares)	2	5
DRSPP proceeds	$ 77	$ 184
Reallocation of noncontrolling interest in the Operating Partnership	$ (42,841)	$ (10,147)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	78	(12)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	$ 4,601	$ 7,559
Cash distributions declared	(48,356)	(52,236)
Ending balance	$ 3,473,528	$ 4,219,126
Ending balance (units)	64,806	64,373
SL Green Operating Partnership | Accumulated Other Comprehensive Loss
Increase (Decrease) in Partner's Capital
Beginning balance	$ 17,477	$ 49,604
Other comprehensive income	22,674	(30,176)
Ending balance	40,151	19,428
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Beginning balance	69,610	61,889
Net income (loss)	(1,294)	(1,625)
Redemption and conversion of common units	(5,674)
Contributions to consolidated joint venture interests		8,560
Cash distributions to noncontrolling interests	(1,283)	(136)
Ending balance	$ 68,037	$ 68,688

Consolidated Statements of Ca_2

Consolidated Statements of Capital (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash distributions declared (per common unit, none of which represented a return of capital for federal income tax purposes) (in dollars per share)	$ 0.750	$ 0.812
SL Green Operating Partnership
Cash distributions declared (per common unit, none of which represented a return of capital for federal income tax purposes) (in dollars per share)	$ 0.750	$ 0.812

Consolidated Statements of Ca_3

Consolidated Statements of Cash Flows (Partnership) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Operating Activities
Net income (loss)	$ 18,389	$ (38,357)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	50,123	80,803
Equity in net (income) loss from unconsolidated joint ventures	(111,160)	7,412
Distributions of cumulative earnings from unconsolidated joint ventures	68	258
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(26,764)	79
Purchase price and other fair value adjustments	50,492	(239)
Depreciable real estate reserves and impairment	52,118	0
Loss on sale of real estate, net	0	1,651
Loan loss reserves and other investment reserves, net of recoveries	0	6,890	$ 6,890
Deferred rents receivable	(3,721)	(7,431)
Non-cash lease expense	5,003	5,261
Other non-cash adjustments	11,166	(3,271)
Changes in operating assets and liabilities:
Tenant and other receivables	(3,174)	(969)
Related party receivables	245	577
Deferred lease costs	(3,735)	(3,911)
Other assets	(12,644)	(11,394)
Accounts payable, accrued expenses, other liabilities and security deposits	(50,003)	4,656
Deferred revenue	3,017	2,450
Lease liability - operating leases	(4,097)	(2,116)
Net cash (used in) provided by operating activities	(24,677)	42,349
Investing Activities
Additions to land, buildings and improvements	(55,316)	(61,918)
Acquisition deposits and deferred purchase price	(12,817)	0
Investments in unconsolidated joint ventures	(23,830)	(22,985)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	71,545	41,812
Net proceeds from disposition of real estate/joint venture interest	26,420	0
Other investments	(2,770)	(17,700)
Origination of debt and preferred equity investments	(6,945)	(5,578)
Net cash used in investing activities	(3,713)	(66,369)
Financing Activities
Proceeds from mortgages and other loans payable	493	0
Repayments of mortgages and other loans payable	(1,501)	(1,473)
Proceeds from revolving credit facility, term loans and unsecured notes	130,000	143,000
Repayments of revolving credit facility, term loans and unsecured notes	(40,000)	(78,000)
Proceeds from stock options exercised and DRSPP issuance	77	184
Redemption of OP units	(18,608)	(5,220)
Distributions to noncontrolling interests in other partnerships	(1,283)	(136)
Contributions from noncontrolling interests in other partnerships	0	426
Distributions paid on common and preferred units	(54,142)	(57,373)
Deferred loan costs	(60)	(358)
Net cash provided by (used in) financing activities	11,367	(2,772)
Net decrease in cash, cash equivalents, and restricted cash	(17,023)	(26,792)
Cash, cash equivalents, and restricted cash at beginning of year	335,519	384,054	384,054
Cash, cash equivalents, and restricted cash at end of period	318,496	357,262	335,519
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Fair value adjustment to noncontrolling interest in the Operating Partnership	42,841	10,147
Consolidation of a subsidiary	6,678	0
Consolidation of mortgage loan payable	205,000	0
Acquisition of subsidiary interest from noncontrolling interest	5,674	0
Contribution to consolidated joint venture interest	0	8,134
Removal of fully depreciated commercial real estate properties	3,354	4,247
Share repurchase or redemption payable	5,012	0
Cash and cash equivalents	196,035	158,937	221,823
Restricted cash	122,461	198,325	113,696
Total cash, cash equivalents, and restricted cash	318,496	357,262	335,519
SL Green Operating Partnership
Operating Activities
Net income (loss)	18,389	(38,357)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	50,123	80,803
Equity in net (income) loss from unconsolidated joint ventures	(111,160)	7,412
Distributions of cumulative earnings from unconsolidated joint ventures	68	258
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(26,764)	79
Purchase price and other fair value adjustments	50,492	(239)
Depreciable real estate reserves and impairment	52,118	0
Loss on sale of real estate, net	0	1,651
Loan loss reserves and other investment reserves, net of recoveries	0	6,890
Deferred rents receivable	(3,721)	(7,431)
Non-cash lease expense	5,003	5,261
Other non-cash adjustments	11,166	(3,271)
Changes in operating assets and liabilities:
Tenant and other receivables	(3,174)	(969)
Related party receivables	245	577
Deferred lease costs	(3,735)	(3,911)
Other assets	(12,644)	(11,394)
Accounts payable, accrued expenses, other liabilities and security deposits	(50,003)	4,656
Deferred revenue	3,017	2,450
Lease liability - operating leases	(4,097)	(2,116)
Net cash (used in) provided by operating activities	(24,677)	42,349
Investing Activities
Additions to land, buildings and improvements	(55,316)	(61,918)
Acquisition deposits and deferred purchase price	(12,817)	0
Investments in unconsolidated joint ventures	(23,830)	(22,985)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	71,545	41,812
Net proceeds from disposition of real estate/joint venture interest	26,420	0
Other investments	(2,770)	(17,700)
Origination of debt and preferred equity investments	(6,945)	(5,578)
Net cash used in investing activities	(3,713)	(66,369)
Financing Activities
Proceeds from mortgages and other loans payable	493	0
Repayments of mortgages and other loans payable	(1,501)	(1,473)
Proceeds from revolving credit facility, term loans and unsecured notes	130,000	143,000
Repayments of revolving credit facility, term loans and unsecured notes	(40,000)	(78,000)
Proceeds from stock options exercised and DRSPP issuance	77	184
Redemption of OP units	(18,608)	(5,220)
Distributions to noncontrolling interests in other partnerships	(1,283)	(136)
Contributions from noncontrolling interests in other partnerships	0	426
Distributions paid on common and preferred units	(57,751)	(61,195)
Deferred loan costs	(60)	(358)
Net cash provided by (used in) financing activities	11,367	(2,772)
Net decrease in cash, cash equivalents, and restricted cash	(17,023)	(26,792)
Cash, cash equivalents, and restricted cash at beginning of year	335,519	384,054	384,054
Cash, cash equivalents, and restricted cash at end of period	318,496	357,262	335,519
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Fair value adjustment to noncontrolling interest in the Operating Partnership	42,841	10,147
Consolidation of a subsidiary	6,678	0
Acquisition of subsidiary interest from noncontrolling interest	5,674	0
Contribution to consolidated joint venture interest	0	8,134
Removal of fully depreciated commercial real estate properties	3,354	4,247
Share repurchase or redemption payable	5,012	0
Cash and cash equivalents	196,035	158,937	221,823
Restricted cash	122,461	198,325	113,696
Total cash, cash equivalents, and restricted cash	$ 318,496	$ 357,262	$ 335,519

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2024
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 S.L. Green Management Corp, or the Service Corporation. 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 and S.L. Green Management Corp., respectively, which are 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 March 31, 2024, noncontrolling investors held, in the aggregate, a 6.38% limited partnership interest in the Operating Partnership. We refer to these interests as the noncontrolling interests in the Operating Partnership. The Operating Partnership is considered a variable interest entity, or VIE, in which we are the primary beneficiary. See Note 11, "Noncontrolling Interests on the Company's Consolidated Financial Statements." On March 31, 2024, we owned the following interests in properties in the New York metropolitan area, primarily in midtown Manhattan. Our investments located outside of Manhattan are referred to as the Suburban properties: Consolidated Unconsolidated Total Location Property Number of Buildings Approximate Square Feet (unaudited) Number of Buildings Approximate Square Feet (unaudited) Number of Buildings Approximate Square Feet (unaudited) Weighted Average Leased Occupancy (1) (unaudited) Commercial: Manhattan Office 14 8,753,441 10 13,009,149 24 21,762,590 88.6 % Retail 1 22,648 1 12,946 2 35,594 100.0 % Development/Redevelopment 2 (2) 880,771 2 1,959,426 4 2,840,197 N/A 17 9,656,860 13 14,981,521 30 24,638,381 88.6 % Suburban Office 7 862,800 — — 7 862,800 73.8 % Total commercial properties 24 10,519,660 13 14,981,521 37 25,501,181 88.0 % Residential: Manhattan Residential 1 (2) 140,382 1 221,884 2 362,266 99.6 % Total core portfolio 25 10,660,042 14 15,203,405 39 25,863,447 88.2 % Alternative Strategy Portfolio 2 17,888 8 3,694,956 10 3,712,844 66.1 % (1) The weighted average leased occupancy for commercial properties represents the total leased square footage divided by the total square footage at acquisition. The weighted average leased for residential properties represents the total leased units divided by the total available units. Properties under construction are not included in the calculation of weighted average leased occupancy. (2) As of March 31, 2024, we owned a building at 7 Dey Street / 185 Broadway that was comprised of approximately 140,382 square feet (unaudited) of residential space and approximately 50,206 square feet (unaudited) of office and retail space that is under development. For the purpose of this report, we have included this building in the number of residential properties we own. However, we have included only the residential square footage in the residential approximate square footage, and have listed the balance of the square footage as development square footage. As of March 31, 2024, we also managed one office building and one retail building owned by third parties encompassing approximately 0.4 million square feet (unaudited), and held debt and preferred equity investments with a book value of $352.3 million, excluding debt and preferred equity investments and other financing receivables totaling $4.8 million that are included in balance sheet line items other than the Debt and preferred equity investments line item. 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, subject to the priority distributions with respect to preferred units and special provisions that apply to Long Term Incentive Plan ("LTIP") Units. As the managing general partner of the Operating Partnership, we are required to take such reasonable efforts, as determined by us in our sole discretion, to cause the Operating Partnership to distribute sufficient amounts to enable the payment of sufficient dividends by us to minimize any Federal income or excise tax at the Company level. Under the Operating Partnership Agreement, each limited partner has the right to redeem units of limited partnership interests for cash, or if we so elect, shares of SL Green's common stock on a one-for-one basis. Basis of Quarterly Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for the fair presentation of the financial position of the Company and the Operating Partnership at March 31, 2024 and the results of operations for the periods presented have been included. The operating results for the period presented are not necessarily indicative of the results that may be expected for the year ending December 31, 2024. These financial statements should be read in conjunction with the financial statements and accompanying notes included in the Annual Report on Form 10-K for the year ended December 31, 2023 of the Company and the Operating Partnership. The consolidated balance sheet at December 31, 2023 has been derived from the audited financial statements as of that date but does not include all the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
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. 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 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. Investment in Commercial Real Estate Properties 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 3 years 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 1 year to 15 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 1 year to 15 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. Origination costs are amortized as an expense over the remaining life of the lease and tenant improvements are amortized over the shorter of the remaining life of the lease or useful life of the improvement (or charged against earnings if the lease is terminated prior to its contractual expiration date). When allocating the purchase price of real estate, we assess fair value of the leases based on estimated cash flow projections that utilize appropriate discount 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. The Company classifies those leases under which the Company is the lessee at lease commencement as finance or operating leases. Leases qualify as finance leases if the lease transfers ownership of the asset at the end of the lease term, the lease grants an option to purchase the asset that we are reasonably certain to exercise, the lease term is for a major part of the remaining economic life of the asset, or the present value of the lease payments exceeds substantially all of the fair value of the asset. Leases that do not qualify as finance leases are deemed to be operating leases. At lease commencement the Company records a lease liability which is measured as the present value of the lease payments and a right of use asset which is measured as the amount of the lease liability and any initial direct costs incurred. The Company applies a discount rate to determine the present value of the lease payments. If the rate implicit in the lease is known, the Company uses that rate. If the rate implicit in the lease is not known, the Company uses a discount rate reflective of the Company’s collateralized borrowing rate given the term of the lease. To determine the discount rate, the Company employs a third party specialist to develop an analysis based primarily on the observable borrowing rates of the Company, other REITs, and other corporate borrowers with long-term borrowings. On the consolidated statements of operations, operating leases are expensed through operating lease rent while financing leases are expensed through amortization and interest expense. When applicable, the Company combines the consideration for lease and non-lease components in the calculation of the value of the lease obligation and right-of-use asset. On a periodic basis, we assess whether there are any indications that the value of our real estate consolidated properties may be impaired or that their carrying value may not be recoverable. A consolidated property's value is considered impaired if management's estimate of the aggregate future cash flows (undiscounted) and terminal value 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 fair value of the property as calculated in accordance with Accounting Standards Codification, or ASC 820. We also evaluate our real estate consolidated properties for impairment when a property has been classified as held for sale. Real estate assets held for sale are valued at the lower of their carrying value or fair value less costs to sell and depreciation expense is no longer recorded. In April 2024, the Company entered into an agreement to sell the property at 719 Seventh Avenue for $30.5 million. The transaction is subject to customary conditions. As a result of the pending sale, the Company recorded a $46.3 million charge to reduce the carrying value of its investment to the contracted purchase price for the three months ended March 31, 2024, which is included in Depreciable real estate reserves and impairments in the consolidated statements of operations. For the three months ended March 31, 2024, we recognized a reduction of rental revenue of ($0.1 million) for the amortization of aggregate above-market leases in excess of below-market leases resulting from the allocation of the purchase price of the applicable properties. For the three months ended March 31, 2023, we recognized $8.2 million of rental revenue for the amortization of aggregate below-market leases in excess of above-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 March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Identified intangible assets (included in other assets): Gross amount $ 273,010 $ 189,680 Accumulated amortization (185,470) (184,902) Net $ 87,540 $ 4,778 Identified intangible liabilities (included in deferred revenue): Gross amount $ 226,034 $ 205,394 Accumulated amortization (202,178) (202,089) Net $ 23,856 $ 3,305 Cash and Cash Equivalents We consider all highly liquid investments with maturity of three months or less when purchased to be cash equivalents. 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. Fair Value Measurements See Note 16, "Fair Value Measurements." Investment in Marketable Securities At acquisition, we designate a debt security as held-to-maturity, available-for-sale, or trading. As of March 31, 2024, we did not have any debt securities designated as held-to-maturity or trading. We account for our available-for-sale securities at fair value pursuant to ASC 820-10, with the net unrealized gains or losses reported as a component of accumulated other comprehensive income or loss. The cost of marketable securities sold and the amount reclassified out of accumulated other comprehensive income into earnings is determined using the specific identification method. Credit losses are recognized in accordance with ASC 326. We account for equity marketable securities at fair value pursuant to ASC 820-10, with the net unrealized gains or losses reported in net income. As of March 31, 2024 and December 31, 2023, we held the following marketable securities (in thousands): March 31, 2024 December 31, 2023 Commercial mortgage-backed securities $ 10,673 $ 9,591 Total investment in marketable securities $ 10,673 $ 9,591 The cost basis of the commercial mortgage-backed securities was $11.5 million as of March 31, 2024 and December 31, 2023. These securities mature at various times through 2030. As of March 31, 2024, one security was in an unrealized gain position of $0.1 million with a fair market value of $5.4 million, and one security was in an unrealized loss position of $0.9 million with a fair market value of $5.3 million and was in a continuous unrealized loss position for more than 12 months. All securities were in an unrealized loss position as of December 31, 2023 with an unrealized loss of $1.9 million, a fair market value of $9.6 million and were in a continuous unrealized loss position for more than 12 months. We do not intend to sell our other securities, and it is more likely than not that we will not be required to sell the investments before recovery of their amortized cost bases. We did not dispose of any debt marketable securities during the three months ended March 31, 2024 and 2023. We held no equity marketable securities as of March 31, 2024 and December 31, 2023. 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 each joint ventures' actual and projected cash flows. Aside from charges noted in Note 6, "Investments in Unconsolidated Joint Ventures," we do not believe that the values of any of our equity investments were impaired at March 31, 2024. Deferred Lease Costs Deferred lease costs consist of incremental fees and direct costs that would not have been incurred if the lease had not been obtained and are amortized on a straight-line basis over the related lease term. Lease Classification Lease classification for leases under which the Company is the lessor is evaluated at lease commencement and leases not classified as sales-type leases or direct financing leases are classified as operating leases. Leases qualify as sales-type leases if the contract includes either transfer of ownership clauses, certain purchase options, a lease term representing a major part of the economic life of the asset, or the present value of the lease payments and residual guarantees provided by the lessee exceeds substantially all of the fair value of the asset. Additionally, leasing an asset so specialized that it is not deemed to have any value to the Company at the end of the lease term may also result in classification as a sales-type lease. Leases qualify as direct financing leases when the present value of the lease payments and residual value guarantees provided by the lessee and unrelated third parties exceeds substantially all of the fair value of the asset and collection of the payments is probable. Revenue Recognition Rental revenue for operating leases is recognized on a straight-line basis over the term of the lease. Rental revenue recognition commences when the leased space is available for its intended use by the lessee. To determine whether the leased space is available for its intended use by the lessee, management evaluates whether we or the tenant are 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 of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space. 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. In addition to base rent, our tenants also generally will pay variable rent, which represents their pro rata share of increases in real estate taxes and certain operating expenses for the building over a base year. In some leases, in lieu of paying additional rent based upon increases in certain 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. Rental revenue is recognized if collectability is probable. If collectability of substantially all of the lease payments is assessed as not probable, any difference between the rental revenue recognized to date and the lease payments that have been collected is recognized as a current-period adjustment to rental revenue. A subsequent change in the assessment of collectability to probable may result in a current-period adjustment to rental revenue for any difference between the rental revenue that would have been recognized if collectability had always been assessed as probable and the rental revenue recognized to date. The Company provides its tenants with certain customary services for lease contracts such as common area maintenance and general security. We have elected to combine the non-lease components with the lease components of our operating lease agreements and account for them as a single lease component in accordance with ASC 842. We record a gain or loss on sale of real estate assets when we no longer have a controlling financial interest in the entity owning the real estate, a contract exists with a third party and that third party has control of the assets acquired. Investment income on debt and preferred equity investments is accrued based on the contractual terms of the instruments and when 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 collectible. 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 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 cash flows 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. We consider a debt and preferred equity investment to be past due when amounts contractually due have not been paid. 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 is resumed on any debt or preferred equity investment that is on non-accrual status when such debt or preferred equity investment becomes contractually current and performance is demonstrated to be resumed. 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 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 operations. 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. Revenues from the sale of SUMMIT tickets are recognized upon admission or ticket expirations. Deferred revenue related to unused and unexpired tickets as of March 31, 2024 and 2023 was $4.2 million and $3.2 million, respectively, and is included in Deferred revenue on the consolidated balance sheets. Debt and Preferred Equity Investments Debt and preferred equity investments are presented at the net amount expected to be collected in accordance with ASC 326. An allowance for loan losses is deducted from the amortized cost basis of the financial assets to present the net carrying value at the amount expected to be collected through the expected maturity date of such investments. The expense for loan loss and other investment reserves is the charge to earnings to adjust the allowance for loan losses to the appropriate level. Amounts are written off from the allowance when we de-recognize the related investment either as a result of a sale of the investment or acquisition of equity interests in the collateral. The Company evaluates the amount expected to be collected based on current market and economic conditions, historical loss information, and reasonable and supportable forecasts. The Company's assumptions are derived from both internal data and external data which may include, among others, governmental economic projections for the New York City Metropolitan area, public data on recent transactions and filings for securitized debt instruments. This information is aggregated by asset class and adjusted for duration. Based on these inputs, loans are evaluated at the individual asset level. In certain instances, we may also use a probability-weighted model that considers the likelihood of multiple outcomes and the amount expected to be collected for each outcome. The evaluation of the possible credit deterioration associated with the performance and/or value of the underlying collateral property as well as the financial and operating capability of the borrower/sponsor requires significant judgment, which include both asset level and market assumptions over the relevant time period. In addition, quarterly, the Company assigns each loan a risk rating. Based on a 3-point scale, loans are rated “1” through “3,” from lower risk to higher risk, which ratings are defined as follows: 1 - Low Risk Assets - Low probability of loss, 2 - Watch List Assets - Higher potential for loss, 3 - High Risk Assets - Loss more likely than not. Loans with risk ratings of 2 or above are evaluated to determine whether the expected risk of loss is appropriately captured through the combination of our expectations of current conditions, historical loss information and supportable forecasts described above or whether risk characteristics specific to the loan warrant the use of a probability-weighted model. Financing investments that are classified as held for sale are carried at the expected amount to be collected 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 expected amount to be collected. Other financing receivables that are included in balance sheet line items other than the Debt and preferred equity investments line are also measured at the net amount expected to be collected. Accrued interest receivable amounts related to these debt and preferred equity investment and other financing receivables are recorded at the net amount expected to be collected within Other assets in the consolidated balance sheets. Accrued interest receivables that are written off are recognized as an expense in loan loss and other investment reserves. 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 its 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 its 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. We have elected, and may elect in the future, to treat certain of our 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, state and local corporate tax liability for these entities. During the three months ended March 31, 2024 and 2023, we recorded Federal, state and local tax provisions totaling $0.7 million and $0.8 million, respectively, for these entities. SUMMIT is also held in a TRS and pays Federal, state and local taxes. During the quarter ended March 31, 2024, we recorded Federal, state and local tax benefit for SUMMIT of $1.3 million. During the quarter ended March 31, 2023, we recorded Federal, state and local tax expense for SUMMIT of $1.3 million. 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. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash investments, debt and preferred equity investments and accounts receivable. We place our cash investments 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 initial and ongoing evaluations of the credit quality 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 potential source of funds to offset the economic costs associated with lost revenue from that tenant and the costs associated with re-tenanting a space. The properties in our real estate portfolio are located in the New York metropolitan area, principally in Manhattan. Our tenants operate in various industries. Other than one tenant, Paramount Global (formerly ViacomCBS Inc.), which accounted for 5.5% of our share of annualized cash rent as of March 31, 2024, no other tenant in our portfolio accounted for more than 5.0% of our share of annualized cash rent, including our share of joint venture annualized cash rent, for the three months ended March 31, 2024. For the three months ended March 31, 2024, the following properties contributed more than 5.0% of our annualized cash rent from office properties, including our share of annualized cash rent from joint venture office properties: Property Three months ended March 31, 2024 One Vanderbilt Avenue 16.7% 11 Madison Avenue 8.8% 420 Lexington Ave 7.2% 1515 Broadway 6.7% 1185 Avenue of the Americas 6.0% 245 Park Avenue 5.6% 280 Park Avenue 5.0% Reclassification Certain prior year balances have been reclassified to conform to our current year presentation. As of December 31, 2023, SUMMIT met the criteria of a reportable operating segment pursuant to the guidance in ASC 280. Accordingly, we reclassified SUMMIT Operator revenue, SUMMIT Operator expenses, and SUMMIT Operator tax expense to separate financial statement line items in our consolidated statements of operations. These items were previously presented on a net basis in Other income. Additionally, the depreciation and amortization of SUMMIT assets are included in Depreciation and amortization in our consolidated statements of operations. Prior period balances have been reclassified to conform to the current period presentation. Accounting Standards Updates In December 2023, the FASB issued ASU No. 2023-09 Income Taxes (Topic 740) - Improvements to Income Tax Disclosures. The objective of the amendments in ASU 2023-09 related to the rate reconciliation and income taxes paid disclosures are to improve transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. The amendment will require that public entities on an annual basis disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold. Additionally, the amendment will require that all entities disclose on an annual basis the amount of taxes paid (net of refunds received) disaggregated by federal, state and foreign taxes as well as disaggregated by individual jurisdictions that meet a quantitative threshold. ASU 2023-09 is effective prospectively for annual periods beginning after December 15, 2024. Early adoption and retrospective application is permitted. We are currently evaluating the impact of the adoption of ASU 2023-09 on our consolidated financial statements, but do not believe the adoption of this standard will have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU No. 2023-07 Segment Reporting (Topic 280) - Improvements to Reportable Segment Disclosures. ASU 2023-07 amends the reportable segment disclosure requirements to enhance disclosures about significant segment expenses. The objective of the amendment is to improve financial reporting by requiring disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. The amendment will require that a public entity disclose, on an annual and interim basis, significant segment expenses that are regularly provided to the chief operating decision maker ("CODM") and included within each reported measure of segment profit or loss (collectively referred to as the "significant expense principle"). Additionally, the amendment will require an entity to disclose an amount for "other segment items" by reportable segment and a description of its composition as well as require annual disclosures about a reportable segment's profit or loss and assets currently required by Topic 280 in interim periods. Lastly, the amendment will require a public entity to disclose the title and position of the CODM and an explanation of how the CODM uses the reported measures of segment profit or loss in assessing segment performance and deciding to allocate resources. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted and should be applied retrospectively to all prior periods presented in the financial statements. We are currently evaluating the impact of the adoption of ASU 2023-07 on our consolidated financial statements, but do not believe the adoption of this standard will have a material impact on our consolidated financial statements. In August 2023, the FASB issued ASU No. 2023-05 Business Combinations - Joint Venture Formations (Subtopic 805-60) Recognition and Initial Measurement. ASU 2023-05 addresses the accounting for contributions made to a joint venture, upon formation, in a joint venture's separate financial statements. The objectives of the amendments are to provide decision-useful information to investors and other allocators of capital in a joint venture's financial statements and reduce diversity in practice. The amendments require that a joint venture apply the following key adaptations from the business combinations guidance upon formation: (i) a joint venture is the formation of a new entity without an accounting acquirer, (ii) a joint venture measures its identifiable net assets and goodwill, if any, at the formation date, (iii) initial measurement of a joint venture's total net assets is equal to the fair value of 100 percent of the joint venture's equity, and (iv) a joint venture provides relevant disclosures. ASU 2023-05 is effective prospectively for all joint venture formations with a formation date on or after January 1, 2025, with early adoption permitted in any interim or annual period in which financial statements have not yet been issued, either prospectively or retrosp

Property Acquisitions and Conso

Property Acquisitions and Consolidations	3 Months Ended
	Mar. 31, 2024
Business Combination and Asset Acquisition [Abstract]
Property Acquisitions and Consolidations	Property Acquisitions and Consolidations Property Acquisitions During the three months ended March 31, 2024, we did not acquire any properties from a third party. Property Consolidations The following table summarizes the properties consolidated during the three months ended March 31, 2024: Property Consolidation Date Property Type Approximate Square Feet Gross Asset Valuation 10 East 53rd Street (1) March 2024 Fee Interest 354,300 $ 236.0 (1) In March 2024, the Company entered into an agreement to acquire its partner's 45.0% interest in the joint venture for cash consideration of $7.2 million, which is net of all outstanding debt obligations at contract signing. As a result of the contract terms, it was concluded that the joint venture is a VIE in which the Company is the primary beneficiary, and the investment was consolidated in our financial statements. Upon consolidating the entity, the assets and liabilities of the entity were recorded at fair value which resulted in the recognition of a fair value adjustment of ($55.7 million), which is included in Purchase price and other fair value adjustments in the consolidated statements of operations. Prior to March 2024, the investment was accounted for under the equity method. See Note 16, "Fair Value Measurements."

Properties Held for Sale and Pr

Properties Held for Sale and Property Dispositions	3 Months Ended
	Mar. 31, 2024
Discontinued Operations and Disposal Groups [Abstract]
Properties Held for Sale and Property Dispositions	Properties Held for Sale and Property Dispositions Properties Held for Sale As of March 31, 2024, Palisades Premier Conference Center was classified as held for sale as we entered into an agreement to sell the property for $26.3 million. The sale is expected to close in the second quarter of 2024. Property Dispositions During the three months ended March 31, 2024, we did not dispose of any properties.

Debt and Preferred Equity Inves

Debt and Preferred Equity Investments	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Debt and Preferred Equity Investments	Debt and Preferred Equity Investments Below is a summary of the activity in our debt and preferred equity investments for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of year (1) $ 346,745 $ 623,280 Debt investment originations/fundings/accretion (2) 3,487 72,160 Preferred equity investment originations/accretion (2) 2,115 8,142 Redemptions/sales/syndications/equity ownership/amortization — (349,947) Net change in loan loss reserves — (6,890) Balance at end of period (1) (3) $ 352,347 $ 346,745 (1) Net of unamortized fees, discounts, and premiums. (2) Accretion includes amortization of fees and discounts and paid-in-kind investment income. (3) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio. Below is a summary of our debt and preferred equity investments as of March 31, 2024 (dollars in thousands): Floating Rate Fixed Rate Total Carrying Value Senior Financing Maturity (2) Type Carrying Value Face Value Interest Rate (1) Carrying Value Face Value Interest Rate Mezzanine Debt $ 172,232 $ 172,391 S + 4.95% - 12.38% $ 50,000 $ 50,000 8.00% - 8.40% $ 222,232 (3) $ 1,084,257 2024 - 2029 Preferred Equity — — — 130,115 130,115 6.5% 130,115 250,000 2027 Balance at end of period $ 172,232 $ 172,391 $ 180,115 $ 180,115 $ 352,347 $ 1,334,257 (1) Floating interest rates are presented with the stated spread over Term SOFR ("S"). (2) Excludes available extension options to the extent they have not been exercised as of the date of this filing. (3) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio. The following table is a roll forward of our total allowance for loan losses for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of year $ 13,520 $ 6,630 Current period provision for loan loss — 6,890 Balance at end of period (1) $ 13,520 $ 13,520 (1) As of March 31, 2024, all debt and preferred equity investments on non-accrual had an allowance for loan loss except for one debt investment with a carrying value of $49.8 million, which is included in the Company's alternative strategy portfolio. As of March 31, 2024, two investments that are in the Company's alternative strategy portfolio and have a total carrying value, net of reserves, of $49.8 million were not performing in accordance with their respective terms. As of December 31, 2023, the same two investments with a total carrying value, net of reserves, of $49.8 million were not performing in accordance with their respective terms. This is further discussed in the Debt Investments and Preferred Equity Investments tables below. No other financing receivables were 90 days past due as of March 31, 2024 and December 31, 2023. The following table sets forth the carrying value of our debt and preferred equity investment portfolio by risk rating as of March 31, 2024 and December 31, 2023 (dollars in thousands): Risk Rating March 31, 2024 December 31, 2023 1 - Low Risk Assets - Low probability of loss $ 214,740 $ 210,333 2 - Watch List Assets - Higher potential for loss (1) 137,607 136,412 3 - High Risk Assets - Loss more likely than not — — $ 352,347 $ 346,745 (1) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio. The following table sets forth the carrying value of our debt and preferred equity investment portfolio by year of origination and risk rating as of March 31, 2024 (dollars in thousands): As of March 31, 2024 Risk Rating 2024 (1) 2023 (1) 2022 (1) Prior (1) Total 1 - Low Risk Assets - Low probability of loss $ — $ — $ — $ 214,740 $ 214,740 2 - Watch List Assets - Higher potential for loss — — — 137,607 (2) 137,607 3 - High Risk Assets - Loss more likely than not — — — — — $ — $ — $ — $ 352,347 $ 352,347 (1) Year in which the investment was originated or acquired by us or in which a material modification occurred. (2) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio. We have determined that we have one portfolio segment of financing receivables as of March 31, 2024 and December 31, 2023 comprised of commercial real estate which is primarily recorded in debt and preferred equity investments. Included in Other assets is an additional amount of financing receivables representing loans to joint venture partners totaling $5.8 million and $8.8 million as of March 31, 2024 and December 31, 2023, respectively. The Company recorded no provisions for loan losses related to these financing receivables for the three months ended March 31, 2024 and 2023. All of these loans have a risk rating of 2 and were performing in accordance with their respective terms. Debt Investments As of March 31, 2024 and December 31, 2023, we held the following debt investments with an aggregate weighted average current yield of 8.72% as of March 31, 2024 (dollars in thousands): Loan Type March 31, 2024 March 31, 2024 Senior March 31, 2024 Carrying Value (1) December 31, 2023 (1) Maturity (2) Fixed Rate Investments: Mezzanine Loan (3) (4) (6) $ — $ 105,000 $ 13,366 $ 13,366 June 2024 Mezzanine Loan — 95,000 30,000 30,000 January 2025 Mezzanine Loan — 85,000 20,000 20,000 December 2029 Total fixed rate $ — $ 285,000 $ 63,366 $ 63,366 Floating Rate Investments: Mezzanine Loan (5) (6) $ — $ 275,000 $ 50,000 $ 50,000 April 2023 Mezzanine Loan 3,761 54,000 8,243 8,243 May 2024 Mezzanine Loan 370 284,173 64,624 62,333 May 2024 Mezzanine Loan 9,565 186,084 49,519 48,323 January 2026 Total floating rate $ 13,696 $ 799,257 $ 172,386 $ 168,899 Allowance for loan loss $ — $ — $ (13,520) $ (13,520) Total $ 13,696 $ 1,084,257 $ 222,232 $ 218,745 (1) Carrying value is net of discounts, premiums, original issue discounts and deferred origination fees. (2) Represents contractual maturity, excluding any extension options to the extent they have not been exercised as of the date of this filing. (3) Carrying value is net of a $12.0 million participation that was sold and did not meet the conditions for sale accounting. That participation is included in Other assets and Other liabilities on the consolidated balance sheets as a result. (4) This loan went into default and was put on non-accrual in June 2020 and remains on non-accrual as of March 31, 2024. No investment income has been recognized subsequent to it being put on non-accrual. In the first quarter of 2023, the Company fully reserved the balance of the investment. Additionally, we determined the borrower entity to be a VIE, in which we are not the primary beneficiary. (5) This loan went into default and was put on non-accrual in January 2023 and remains on non-accrual as of March 31, 2024. No investment income has been recognized subsequent to it being put on non-accrual. The Company is in discussions with the borrower with respect to the loan. (6) Included in the Company's alternative strategy portfolio. Preferred Equity Investments As of March 31, 2024 and December 31, 2023, we held the following preferred equity investment with an aggregate weighted average current yield of 6.55% as of March 31, 2024 (dollars in thousands): Type March 31, 2024 March 31, 2024 Senior March 31, 2024 Carrying Value (1) December 31, 2023 (1) Mandatory Redemption (2) Preferred Equity $ — $ 250,000 $ 130,115 $ 128,000 February 2027 Allowance for loan loss $ — $ — $ — $ — Total $ — $ 250,000 $ 130,115 $ 128,000 (1) Carrying value is net of deferred origination fees. (2) Represents contractual redemption, excluding any unexercised extension options.

Investments in Unconsolidated J

Investments in Unconsolidated Joint Ventures	3 Months Ended
	Mar. 31, 2024
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 March 31, 2024, the book value of these investments was $3.0 billion, net of investments with negative book values totaling $144.6 million for which we have an implicit commitment to fund future capital needs. As of March 31, 2024 and December 31, 2023, 800 Third Avenue and 625 Madison Avenue are VIEs in which we are not the primary beneficiary. Our net equity investment in these VIEs was $407.5 million and $437.9 million as of March 31, 2024 and December 31, 2023, respectively. Our maximum loss is limited to the amount of our equity investment in these VIEs. See the "Principles of Consolidation" section of Note 2, "Significant Accounting Policies." 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 March 31, 2024: Property Partner Ownership (1) Economic (1) Unaudited Approximate Square Feet 100 Park Avenue Prudential Real Estate Investors 49.90% 49.90% 834,000 800 Third Avenue Private Investors 60.52% 60.52% 526,000 919 Third Avenue New York State Teacher's Retirement System 51.00% 51.00% 1,454,000 11 West 34th Street (2) Private Investor / Wharton Properties 30.00% 30.00% 17,150 280 Park Avenue Vornado Realty Trust 50.00% 50.00% 1,219,158 1552-1560 Broadway (2) (3) Wharton Properties 50.00% 50.00% 57,718 650 Fifth Avenue (2) (4) Wharton Properties 50.00% 50.00% 69,214 11 Madison Avenue PGIM Real Estate 60.00% 60.00% 2,314,000 One Vanderbilt Avenue National Pension Service of Korea / Hines Interest LP 71.01% 71.01% 1,657,198 Worldwide Plaza (2) RXR Realty / New York REIT 24.95% 24.95% 2,048,725 1515 Broadway Allianz Real Estate of America 56.87% 56.87% 1,750,000 2 Herald Square (2) (5) Israeli Institutional Investor 95.00% 95.00% 369,000 115 Spring Street (2) Private Investor 51.00% 51.00% 5,218 15 Beekman (6) A fund managed by Meritz Alternative Investment Management 20.00% 20.00% 221,884 85 Fifth Avenue Wells Fargo 36.27% 36.27% 12,946 One Madison Avenue (7) National Pension Service of Korea / Hines Interest LP / International Investor 25.50% 25.50% 1,048,700 220 East 42nd Street A fund managed by Meritz Alternative Investment Management 51.00% 51.00% 1,135,000 450 Park Avenue (8) Korean Institutional Investor / Israeli Institutional Investor 50.10% 25.10% 337,000 5 Times Square (2) RXR Realty led investment group 31.55% 31.55% 1,131,735 245 Park Avenue (9) U.S. Affiliate of Mori Trust Co., Ltd 50.10% 50.10% 1,782,793 625 Madison Avenue (10) Private Investor 90.43% 90.43% 563,000 (1) Ownership interest and economic interest represent the Company's interests in the joint venture as of March 31, 2024. Changes in ownership or economic interests within the current year are disclosed in the notes below. (2) Included in the Company's alternative strategy portfolio. (3) The joint venture owns a long-term leasehold interest in the retail space and certain other spaces at 1560 Broadway, which is adjacent to 1552 Broadway. (4) The joint venture owns a long-term leasehold interest in the retail space at 650 Fifth Avenue. (5) In January 2024, the Company closed on the acquisition of interests in the joint venture that owns the leasehold interest for no consideration, which increases the Company's interest in the joint venture to 95.0%. (6) In 2020, the Company formed a joint venture, which then entered into a long-term sublease with the Company. (7) In 2021, the Company admitted an additional partner to the development project with the partner's indirect ownership in the joint venture totaling 25.0%. The transaction did not meet sale accounting under ASC 860 and, as a result, was treated as a secured borrowing for accounting purposes and is included in Other liabilities in our consolidated balance sheets at March 31, 2024 and December 31, 2023. (8) The 50.1% ownership interest reflected in this table is comprised of our 25.1% economic interest and a 25.0% economic interest held by a third-party. The third-party's economic interest is held within a joint venture that we consolidate and recognize in Noncontrolling interests in other partnerships on our consolidated balance sheet. An additional third-party owns the remaining 49.9% economic interest in the property. (9) In June 2023, the Company sold a 49.9% interest, which resulted in the Company no longer retaining a controlling interest in the entity, as defined in ASC 810, and deconsolidation of the 50.1% interest we retained. We recorded our investment at fair value which resulted in the recognition of a fair value adjustment of ($17.0 million) during the year ended December 31, 2023. The fair value of our investment was determined by the terms of the joint venture agreement. (10) In September 2023, following a UCC foreclosure, the Company converted its previous mezzanine debt investments in the fee interest to a 90.43% ownership interest. In December 2023, together with its joint venture partner, the Company entered into a contract to sell the fee ownership in the property. In connection with this contract, the Company recorded a charge of $23.1 million for the year ended December 31, 2023. As of March 31, 2024, the transaction has not closed and the Company recorded an additional charge of $5.9 million for capital contributions required during the quarter, which is included in Depreciable real estate reserves and impairments in the consolidated statements of operations. This transaction is expected to close in the second quarter of 2024. Disposition of Joint Venture Interests or Properties The following table summarizes the investments in unconsolidated joint ventures sold during the three months ended March 31, 2024: Property Ownership Interest Sold Disposition Date Gross Asset Valuation (in millions) Gain on Sale (in millions) (1) 717 Fifth Avenue 10.92% January 2024 $ 963.0 $ 26.9 (1) Represents the Company's share of the gain. Joint Venture Mortgages and Other Loans Payable We generally finance our joint ventures with non-recourse debt. In certain cases, we may provide guarantees or master leases, which terminate upon the satisfaction of specified circumstances or repayment of the underlying loans. The mortgage notes and other loans payable collateralized by the respective joint venture properties and assignment of leases as of March 31, 2024 and December 31, 2023, respectively, are as follows (dollars in thousands): Principal Outstanding Principal Outstanding Economic Current Maturity Final Maturity Interest March 31, 2024 December 31, 2023 Property Interest (1) Date Date (2) Rate (3) Gross SLG Share Gross SLG Share Fixed Rate Debt: 220 East 42nd Street 51.00 % June 2024 June 2025 5.86% $ 505,412 $ 257,760 $ 505,412 $ 257,760 650 Fifth Avenue (4) 50.00 % July 2024 July 2024 5.45% 65,000 32,500 65,000 32,500 5 Times Square (4) 31.55 % September 2024 September 2026 7.18% 514,897 162,450 477,783 150,740 1515 Broadway 56.87 % March 2025 March 2025 3.93% 756,777 430,371 762,002 433,344 115 Spring Street (4) 51.00 % March 2025 March 2025 5.50% 65,550 33,431 65,550 33,431 450 Park Avenue 25.10 % June 2025 June 2027 6.10% 273,616 68,678 271,394 68,120 11 Madison Avenue 60.00 % September 2025 September 2025 3.84% 1,400,000 840,000 1,400,000 840,000 One Madison Avenue (5) 25.50 % November 2025 November 2026 3.59% 769,105 196,122 733,103 186,941 15 Beekman 20.00 % January 2026 January 2028 5.99% 120,000 24,000 — — 800 Third Avenue 60.52 % February 2026 February 2026 3.37% 177,000 107,120 177,000 107,120 919 Third Avenue 51.00 % April 2026 April 2028 6.11% 500,000 255,000 500,000 255,000 625 Madison Avenue (6) 90.43 % December 2026 December 2026 5.07% 201,570 182,280 199,987 180,848 245 Park Avenue 50.10 % June 2027 June 2027 4.30% 1,768,000 885,768 1,768,000 885,768 Worldwide Plaza (4) 24.95 % November 2027 November 2027 3.98% 1,200,000 299,400 1,200,000 299,400 One Vanderbilt Avenue 71.01 % July 2031 July 2031 2.95% 3,000,000 2,130,300 3,000,000 2,130,300 10 East 53rd Street — — 220,000 121,000 717 Fifth Avenue — — 655,328 71,536 Total fixed rate debt $ 11,316,927 $ 5,905,180 $ 12,000,559 $ 6,053,808 Floating Rate Debt: 11 West 34th Street (4) 30.00 % February 2023 (7) February 2023 (7) L+ 1.45% $ 23,000 $ 6,900 $ 23,000 $ 6,900 1552 Broadway (4) 50.00 % February 2024 (8) February 2024 (8) S+ 2.75% 193,132 96,566 193,133 96,567 100 Park Avenue 49.90 % May 2024 (9) December 2025 (10) S+ 2.36% 360,000 179,640 360,000 179,640 650 Fifth Avenue (4) 50.00 % July 2024 July 2024 S+ 2.25% 210,000 105,000 210,000 105,000 5 Times Square (4) 31.55 % September 2024 September 2026 S+ 5.61% 615,094 194,062 610,010 192,458 280 Park Avenue (11) 50.00 % September 2024 September 2024 S+ 2.03% 1,200,000 600,000 1,200,000 600,000 2 Herald Square — — 182,500 93,075 15 Beekman — — 124,137 24,827 Total floating rate debt $ 2,601,226 $ 1,182,168 $ 2,902,780 $ 1,298,467 Total joint venture mortgages and other loans payable $ 13,918,153 $ 7,087,348 $ 14,903,339 $ 7,352,275 Deferred financing costs, net (93,904) (50,598) (104,062) (54,865) Total joint venture mortgages and other loans payable, net $ 13,824,249 $ 7,036,750 $ 14,799,277 $ 7,297,410 (1) Economic interest represents the Company's interests in the joint venture as of March 31, 2024. Changes in ownership or economic interests, if any, within the current year are disclosed in the notes to the investment in unconsolidated joint ventures table above. (2) Reflects exercise of all available options. The ability to exercise extension options may be subject to certain conditions, including meeting tests based on the operating performance of the property. (3) Interest rates as of March 31, 2024, taking into account interest rate hedges in effect during the period. Floating rate debt is presented with the stated spread over Term SOFR ("S"). (4) Included in the Company's alternative strategy portfolio. (5) The loan is a $1.25 billion construction facility with an initial term of five years with one, one year extension option. Advances under the loan are subject to costs incurred. In conjunction with the loan, the Company provided partial guarantees for interest and principal payments, the amounts of which are based on certain construction milestones and operating metrics. In July 2023, the facility was modified, which will allow the partnership to utilize the final tranche of the facility for an expanded range of uses, including additional amenities funded by construction cost savings and for hedging activities in contemplation of a permanent financing. (6) Represents $170.5 million of loan principal and $31.1 million of accrued interest. (7) The Company's joint venture partner is in discussions with the lender on resoluteness, given that the loan is past maturity. (8) The Company is in discussions with the lender on resoluteness, given that the loan is past maturity. (9) In April 2024, together with its joint venture partner, the Company exercised an extension option through December 2024. (10) As-of-right extension. (11) In April 2024, together with our joint venture partner, closed on a modification and extension of the $1.075 billion securitized mortgage loan. The modification extended the maturity date to September 2026, with the partnership's option to extend to a fully extended maturity date of September 2028. The interest rate was maintained at 1.78% over Term SOFR, which the Company fixed at 5.91% for its share of the debt through the fully extended maturity date. The partnership separately modified and extended the $125.0 million mezzanine loan and subsequently repaid the loan for $62.5 million. We are entitled to receive fees for providing management, leasing, construction supervision and asset management services to certain of our joint ventures. We earned $4.9 million and $4.9 million from these services, net of our ownership share of the joint ventures, for the three months ended March 31, 2024 and 2023, 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 March 31, 2024 and December 31, 2023 are as follows (in thousands): March 31, 2024 December 31, 2023 Assets (1) Commercial real estate property, net $ 18,024,642 $ 18,467,340 Cash and restricted cash 608,462 656,038 Tenant and other receivables, related party receivables, and deferred rents receivable 634,813 673,532 Other assets 2,538,878 2,584,765 Total assets $ 21,806,795 $ 22,381,675 Liabilities and equity (1) Mortgages and other loans payable, net $ 13,824,249 $ 14,799,277 Deferred revenue 1,070,740 1,108,180 Lease liabilities 987,299 990,276 Other liabilities 430,533 447,705 Equity 5,493,974 5,036,237 Total liabilities and equity $ 21,806,795 $ 22,381,675 Company's investments in unconsolidated joint ventures $ 2,984,786 $ 2,983,313 (1) At March 31, 2024, $548.2 million of net unamortized basis differences between the amount at which our investments are carried and our share of equity in net assets of the underlying property will be amortized through equity in net income (loss) from unconsolidated joint ventures over the remaining life of the underlying items having given rise to the differences. The combined statements of operations for the unconsolidated joint ventures, from acquisition date through the three months ended March 31, 2024 and 2023, are as follows (in thousands): Three Months Ended March 31, 2024 2023 Total revenues $ 365,339 $ 389,452 Operating expenses 65,750 61,968 Real estate taxes 75,632 65,740 Operating lease rent 9,025 7,181 Interest expense, net of interest income 149,854 129,477 Amortization of deferred financing costs 6,072 7,045 Depreciation and amortization 134,178 125,266 Total expenses 440,511 396,677 Gain on early extinguishment of debt 172,519 — Net income (loss) before loss on sale $ 97,347 $ (7,225) Company's equity in net income (loss) from unconsolidated joint ventures $ 111,160 $ (7,412)

Deferred Costs

Deferred Costs	3 Months Ended
	Mar. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs	Deferred Costs Deferred costs as of March 31, 2024 and December 31, 2023 consisted of the following (in thousands): March 31, 2024 December 31, 2023 Deferred leasing costs $ 402,025 $ 399,224 Less: accumulated amortization (292,729) (287,761) Deferred costs, net $ 109,296 $ 111,463

Mortgages and Other Loans Payab

Mortgages and Other Loans Payable	3 Months Ended
	Mar. 31, 2024
Mortgages and Other Loans Payable
Mortgages and Other Loans Payable	Mortgages and Other Loans Payable The mortgages and other loans payable collateralized by the respective properties and assignment of leases or debt investments as of March 31, 2024 and December 31, 2023, respectively, were as follows (dollars in thousands): Property Maturity Final Maturity Date (1) Interest Rate (2) March 31, 2024 December 31, 2023 Fixed Rate Debt: 420 Lexington Avenue October 2024 October 2040 3.99% $ 275,737 $ 277,238 10 East 53rd Street May 2025 May 2028 (3) 5.45% 205,000 — 100 Church Street June 2025 June 2027 5.89% 370,000 370,000 7 Dey / 185 Broadway November 2025 November 2026 (3) 6.65% 190,148 190,148 Landmark Square January 2027 January 2027 4.90% 100,000 100,000 485 Lexington Avenue February 2027 February 2027 4.25% 450,000 450,000 Total fixed rate debt $ 1,590,885 $ 1,387,386 Floating Rate Debt: 690 Madison Avenue (4) July 2024 July 2025 S+ 0.50% $ 60,493 $ 60,000 719 Seventh Avenue (4)(5) December 2024 December 2024 S+ 1.31% 50,000 50,000 Total floating rate debt $ 110,493 $ 110,000 Total mortgages and other loans payable $ 1,701,378 $ 1,497,386 Deferred financing costs, net of amortization (6,215) (6,067) Total mortgages and other loans payable, net $ 1,695,163 $ 1,491,319 (1) Reflects exercise of all available options. The ability to exercise extension options may be subject to certain tests based on the operating performance of the property. (2) Interest rate as of March 31, 2024, taking into account interest rate hedges in effect during the period. Floating rate debt is presented with the stated spread over Term SOFR ("S"), unless otherwise specified. (3) As-of-right extension. (4) Included in the Company's alternative strategy portfolio. (5) In April 2024, the Company entered into an agreement to sell 719 Seventh Avenue. In connection with the sale, the Company will repay the existing $50.0 million mortgage for $32.0 million. As of March 31, 2024 and December 31, 2023, the gross book value of the properties collateralizing the mortgages and other loans payable was approximately $2.0 billion and $1.9 billion, respectively. 2021 Credit Facility In December 2021, we entered into an amended and restated credit facility, referred to as the 2021 credit facility, that was previously amended by the Company in November 2017, and was originally entered into by the Company in November 2012. As of March 31, 2024, the 2021 credit facility consisted of a $1.25 billion revolving credit facility, a $1.05 billion term loan (or "Term Loan A"), and a $200.0 million term loan (or "Term Loan B") with maturity dates of May 15, 2026, May 15, 2027, and November 21, 2024, respectively. The revolving credit facility has two six-month, as-of-right extension options to May 15, 2027. We also have an option, subject to customary conditions, to increase the capacity of the credit facility to $4.5 billion at any time prior to the maturity dates for the revolving credit facility and term loans without the consent of existing lenders, by obtaining additional commitments from our existing lenders and other financial institutions. As of March 31, 2024, the 2021 credit facility bore interest at a spread over adjusted Term SOFR plus 10 basis points with an interest period of one or three months, as we may elect, ranging from (i) 72.5 basis points to 140 basis points for loans under the revolving credit facility, (ii) 80 basis points to 160 basis points for loans under Term Loan A, and (iii) 85 basis points to 165 basis points for loans under Term Loan B, in each case based on the credit rating assigned to the senior unsecured long term indebtedness of the Company. In instances where there are either only two ratings available or where there are more than two and the difference between them is one rating category, the applicable rating shall be the highest rating. In instances where there are more than two ratings and the difference between the highest and the lowest is two or more rating categories, then the applicable rating used is the average of the highest two, rounded down if the average is not a recognized category. As of March 31, 2024, the applicable spread over adjusted Term SOFR plus 10 basis points for the 2021 credit facility was 140 basis points for the revolving credit facility, 160 basis points for Term Loan A, and 165 basis points for Term Loan B. 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 the Company. As of March 31, 2024, the facility fee was 30 basis points. As of March 31, 2024, we had no outstanding letters of credit, $650.0 million drawn under the revolving credit facility and $1.25 billion outstanding under the term loan facilities, with total undrawn capacity of $600.0 million under the 2021 credit facility. As of March 31, 2024 and December 31, 2023, the revolving credit facility had a carrying value of $645.1 million and $554.8 million, respectively, net of deferred financing costs. As of March 31, 2024 and December 31, 2023, the term loan facilities had a carrying value of $1.2 billion and $1.2 billion, respectively, net of deferred financing costs. The Company and the Operating Partnership are borrowers jointly and severally obligated under the 2021 credit facility. The 2021 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 March 31, 2024 and December 31, 2023, respectively, by scheduled maturity date (dollars in thousands): Issuance March 31, 2024 March 31, 2024 December 31, Interest Rate (1) Initial Term Maturity Date December 17, 2015 (2) $ 100,000 $ 100,000 $ 100,000 4.27 % 10 December 2025 $ 100,000 $ 100,000 $ 100,000 Deferred financing costs, net — (180) (205) $ 100,000 $ 99,820 $ 99,795 (1) Interest rate as of March 31, 2024. (2) Issued by the Company and the Operating Partnership as co-obligors in a private placement. Restrictive Covenants The terms of the 2021 credit facility and 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 March 31, 2024 and December 31, 2023, 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 floating rate of 26 basis points over the three-month Term SOFR. 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, the 2021 credit facility, trust preferred securities, senior unsecured notes and our share of joint venture debt as of March 31, 2024, including as-of-right extension options, were as follows (in thousands): Scheduled Principal Revolving Unsecured Term Loans Trust Senior Total Joint Remaining 2024 $ 2,987 $ 383,243 $ — $ 200,000 $ — $ — $ 586,230 $ 1,488,241 2025 — 370,000 — — — 100,000 470,000 1,739,239 2026 — 190,148 — — — — 190,148 544,400 2027 — 550,000 650,000 1,050,000 — — 2,250,000 1,185,168 2028 — 205,000 — — — — 205,000 — Thereafter — — — — 100,000 — 100,000 2,130,300 $ 2,987 $ 1,698,391 $ 650,000 $ 1,250,000 $ 100,000 $ 100,000 $ 3,801,378 $ 7,087,348 Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended March 31, 2024 2023 Interest expense before capitalized interest $ 48,869 $ 64,843 Interest on financing leases 1,120 1,106 Capitalized interest (17,949) (25,464) Amortization of discount on assumed debt — 1,487 Interest income (867) (319) Interest expense, net $ 31,173 $ 41,653

Corporate Indebtedness

Corporate Indebtedness	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Corporate Indebtedness	Mortgages and Other Loans Payable The mortgages and other loans payable collateralized by the respective properties and assignment of leases or debt investments as of March 31, 2024 and December 31, 2023, respectively, were as follows (dollars in thousands): Property Maturity Final Maturity Date (1) Interest Rate (2) March 31, 2024 December 31, 2023 Fixed Rate Debt: 420 Lexington Avenue October 2024 October 2040 3.99% $ 275,737 $ 277,238 10 East 53rd Street May 2025 May 2028 (3) 5.45% 205,000 — 100 Church Street June 2025 June 2027 5.89% 370,000 370,000 7 Dey / 185 Broadway November 2025 November 2026 (3) 6.65% 190,148 190,148 Landmark Square January 2027 January 2027 4.90% 100,000 100,000 485 Lexington Avenue February 2027 February 2027 4.25% 450,000 450,000 Total fixed rate debt $ 1,590,885 $ 1,387,386 Floating Rate Debt: 690 Madison Avenue (4) July 2024 July 2025 S+ 0.50% $ 60,493 $ 60,000 719 Seventh Avenue (4)(5) December 2024 December 2024 S+ 1.31% 50,000 50,000 Total floating rate debt $ 110,493 $ 110,000 Total mortgages and other loans payable $ 1,701,378 $ 1,497,386 Deferred financing costs, net of amortization (6,215) (6,067) Total mortgages and other loans payable, net $ 1,695,163 $ 1,491,319 (1) Reflects exercise of all available options. The ability to exercise extension options may be subject to certain tests based on the operating performance of the property. (2) Interest rate as of March 31, 2024, taking into account interest rate hedges in effect during the period. Floating rate debt is presented with the stated spread over Term SOFR ("S"), unless otherwise specified. (3) As-of-right extension. (4) Included in the Company's alternative strategy portfolio. (5) In April 2024, the Company entered into an agreement to sell 719 Seventh Avenue. In connection with the sale, the Company will repay the existing $50.0 million mortgage for $32.0 million. As of March 31, 2024 and December 31, 2023, the gross book value of the properties collateralizing the mortgages and other loans payable was approximately $2.0 billion and $1.9 billion, respectively. 2021 Credit Facility In December 2021, we entered into an amended and restated credit facility, referred to as the 2021 credit facility, that was previously amended by the Company in November 2017, and was originally entered into by the Company in November 2012. As of March 31, 2024, the 2021 credit facility consisted of a $1.25 billion revolving credit facility, a $1.05 billion term loan (or "Term Loan A"), and a $200.0 million term loan (or "Term Loan B") with maturity dates of May 15, 2026, May 15, 2027, and November 21, 2024, respectively. The revolving credit facility has two six-month, as-of-right extension options to May 15, 2027. We also have an option, subject to customary conditions, to increase the capacity of the credit facility to $4.5 billion at any time prior to the maturity dates for the revolving credit facility and term loans without the consent of existing lenders, by obtaining additional commitments from our existing lenders and other financial institutions. As of March 31, 2024, the 2021 credit facility bore interest at a spread over adjusted Term SOFR plus 10 basis points with an interest period of one or three months, as we may elect, ranging from (i) 72.5 basis points to 140 basis points for loans under the revolving credit facility, (ii) 80 basis points to 160 basis points for loans under Term Loan A, and (iii) 85 basis points to 165 basis points for loans under Term Loan B, in each case based on the credit rating assigned to the senior unsecured long term indebtedness of the Company. In instances where there are either only two ratings available or where there are more than two and the difference between them is one rating category, the applicable rating shall be the highest rating. In instances where there are more than two ratings and the difference between the highest and the lowest is two or more rating categories, then the applicable rating used is the average of the highest two, rounded down if the average is not a recognized category. As of March 31, 2024, the applicable spread over adjusted Term SOFR plus 10 basis points for the 2021 credit facility was 140 basis points for the revolving credit facility, 160 basis points for Term Loan A, and 165 basis points for Term Loan B. 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 the Company. As of March 31, 2024, the facility fee was 30 basis points. As of March 31, 2024, we had no outstanding letters of credit, $650.0 million drawn under the revolving credit facility and $1.25 billion outstanding under the term loan facilities, with total undrawn capacity of $600.0 million under the 2021 credit facility. As of March 31, 2024 and December 31, 2023, the revolving credit facility had a carrying value of $645.1 million and $554.8 million, respectively, net of deferred financing costs. As of March 31, 2024 and December 31, 2023, the term loan facilities had a carrying value of $1.2 billion and $1.2 billion, respectively, net of deferred financing costs. The Company and the Operating Partnership are borrowers jointly and severally obligated under the 2021 credit facility. The 2021 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 March 31, 2024 and December 31, 2023, respectively, by scheduled maturity date (dollars in thousands): Issuance March 31, 2024 March 31, 2024 December 31, Interest Rate (1) Initial Term Maturity Date December 17, 2015 (2) $ 100,000 $ 100,000 $ 100,000 4.27 % 10 December 2025 $ 100,000 $ 100,000 $ 100,000 Deferred financing costs, net — (180) (205) $ 100,000 $ 99,820 $ 99,795 (1) Interest rate as of March 31, 2024. (2) Issued by the Company and the Operating Partnership as co-obligors in a private placement. Restrictive Covenants The terms of the 2021 credit facility and 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 March 31, 2024 and December 31, 2023, 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 floating rate of 26 basis points over the three-month Term SOFR. 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, the 2021 credit facility, trust preferred securities, senior unsecured notes and our share of joint venture debt as of March 31, 2024, including as-of-right extension options, were as follows (in thousands): Scheduled Principal Revolving Unsecured Term Loans Trust Senior Total Joint Remaining 2024 $ 2,987 $ 383,243 $ — $ 200,000 $ — $ — $ 586,230 $ 1,488,241 2025 — 370,000 — — — 100,000 470,000 1,739,239 2026 — 190,148 — — — — 190,148 544,400 2027 — 550,000 650,000 1,050,000 — — 2,250,000 1,185,168 2028 — 205,000 — — — — 205,000 — Thereafter — — — — 100,000 — 100,000 2,130,300 $ 2,987 $ 1,698,391 $ 650,000 $ 1,250,000 $ 100,000 $ 100,000 $ 3,801,378 $ 7,087,348 Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended March 31, 2024 2023 Interest expense before capitalized interest $ 48,869 $ 64,843 Interest on financing leases 1,120 1,106 Capitalized interest (17,949) (25,464) Amortization of discount on assumed debt — 1,487 Interest income (867) (319) Interest expense, net $ 31,173 $ 41,653

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions One Vanderbilt Avenue Investment In December 2016, we entered into agreements with entities owned and controlled by our Chairman, Chief Executive Officer and Interim President, Marc Holliday, and our former President, Andrew Mathias, pursuant to which they agreed to make an investment in our One Vanderbilt project (inclusive of the property and SUMMIT One Vanderbilt) at the appraised fair market value for the interests acquired. This investment entitles these entities to receive a percentage of any profits realized by the Company from its One Vanderbilt project in excess of the Company's capital contributions, of approximately 1.27% and 0.85%, respectively, on account of the property and 1.92% and 1.28%, respectively, on account of SUMMIT One Vanderbilt. The entities had no right to any return of capital. Accordingly, subject to previously disclosed repurchase rights, these interests had no value and these entities were not entitled to any amounts (other than limited distributions to cover tax liabilities incurred) unless and until the Company received distributions from the One Vanderbilt project in excess of the Company's aggregate investment in the project. The entities owned and controlled by Messrs. Holliday and Mathias paid $1.4 million and $1.0 million, respectively, which equaled the fair market value of the interests acquired as of the date the investment agreements were entered into as determined by an independent third party appraisal that we obtained. Messrs. Holliday and Mathias have the right to tender their interests in the project upon stabilization (50% within three years after stabilization and 100% three years or more after stabilization). In addition, the agreement calls for us to repurchase these interests in the event of a sale of One Vanderbilt or a transactional change of control of the Company. We also have the right to repurchase these interests on the seven One Vanderbilt Avenue Leases In November 2018, we entered into a lease agreement with the One Vanderbilt Avenue joint venture covering certain floors at the property. In March 2021, the lease commenced and we relocated our corporate headquarters to the leased space. For the three months ended March 31, 2024 and 2023, we recorded $0.7 million and $0.7 million, respectively, of rent expense under the lease. Additionally, in June 2021, we, through a consolidated subsidiary, entered into a lease agreement with the One Vanderbilt Avenue joint venture for SUMMIT One Vanderbilt, which commenced operations in October 2021. For the three months ended March 31, 2024 and 2023, we recorded $6.3 million and $6.3 million, respectively, of rent expense under the lease, including percentage rent, of which $4.1 million and $4.1 million, respectively, was recognized as income as a component of Equity in net income (loss) from unconsolidated joint ventures in our consolidated statements of operations. See Note 20, "Commitments and Contingencies." 719 Seventh Avenue In April 2024, the Company entered into an arms-length arrangement to sell the property at 719 Seventh Avenue for $30.5 million to a special purpose entity ("SPE"), of which our former President and current director, Andrew Mathias, is a partner. No amounts from the transaction will be payable to Mr. Mathias. Mr. Mathias is initially expected to own up to 40% of the equity of the SPE representing an investment by Mr. Mathias of up to approximately $7.0 million in the acquisition of the property. The transaction is subject to customary conditions. Other We are entitled to receive fees for providing management, leasing, construction supervision and asset management services to certain of our joint ventures as further described in Note 6, "Investments in Unconsolidated Joint Ventures." Amounts due from joint ventures, inclusive of our ownership share of the joint ventures, and related parties as of March 31, 2024 and December 31, 2023 consisted of the following (in thousands): March 31, 2024 December 31, 2023 Due from joint ventures $ 10,619 $ 10,603 Other 1,610 1,565 Related party receivables $ 12,229 $ 12,168

Noncontrolling Interests on the

Noncontrolling Interests on the Company's Consolidated Financial Statements	3 Months Ended
	Mar. 31, 2024
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 March 31, 2024 and December 31, 2023, the noncontrolling interest unit holders owned 6.38%, or 4,417,247 units, and 5.75%, or 3,949,448 units, of the Operating Partnership, respectively. As of March 31, 2024, 4,417,247 shares of our 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 our common stock at the end of the reporting period. Below is a summary of the activity relating to the noncontrolling interests in the Operating Partnership for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of period $ 238,051 $ 269,993 Distributions (3,609) (14,779) Issuance of common units 6,025 25,365 Redemption and conversion of common units (13,596) (18,589) Net income (loss) 901 (37,465) Accumulated other comprehensive income (loss) allocation 1,622 (1,960) Fair value adjustment 42,841 15,486 Balance at end of period $ 272,235 $ 238,051 Preferred Units of Limited Partnership Interest in the Operating Partnership Below is a summary of the preferred units of limited partnership interest in the Operating Partnership as of March 31, 2024: Issuance Stated Distribution Rate Number of Units Authorized Number of Units Issued Number of Units Outstanding Annual Dividend Per Unit (1) Liquidation Preference Per Unit (2) Conversion Price Per Unit (3) Date of Issuance Series A (4) 5.00 % 109,161 109,161 109,161 $ 50.0000 $ 1,000.00 $ — August 2015 Series F 7.00 % 60 60 60 70.0000 1,000.00 29.12 January 2007 Series K 3.50 % 700,000 563,954 341,677 0.8750 25.00 134.67 August 2014 Series L 4.00 % 500,000 378,634 372,634 1.0000 25.00 — August 2014 Series R 3.50 % 400,000 400,000 400,000 0.8750 25.00 154.89 August 2015 Series S 4.00 % 1,077,280 1,077,280 1,077,280 1.0000 25.00 — August 2015 Series V (5) 5.00 % 40,000 40,000 40,000 1.2500 25.00 — May 2019 Series W (6) (6) 1 1 1 (6) (6) (6) January 2020 (1) Dividends are cumulative, subject to certain provisions. (2) Units are redeemable at any time at par for cash at the option of the unit holder unless otherwise specified. (3) If applicable, 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) the amount shown in the table. (4) Issued through a consolidated subsidiary. The units are convertible on a one-for-one basis, into the Series B Preferred Units of limited partnership interest, or the Subsidiary Series B Preferred Units. The Subsidiary Series B Preferred Units can be converted at any time, after July 15, 2024 at the option of the unitholder, into a number of common stock equal to 6.71348 shares of common stock for each Subsidiary Series B Preferred Unit. As such, no Subsidiary Series B Preferred Units have been issued as of March 31, 2024 (5) The Series V Preferred Units are redeemable at any time after January 1, 2025 at par for cash at the option of the unit holder. (6) The Series W preferred unit was issued in January 2020 in exchange for the then-outstanding Series O preferred unit. The holder of the Series W preferred unit is entitled to quarterly dividends in an amount calculated as (i) 1,350 multiplied by (ii) the current distribution per common unit of limited partnership in SL Green Operating Partnership. The holder has the right to require the Operating Partnership to repurchase the Series W unit for cash, or convert the Series W unit for Class B units, in each case at a price that is determined based on the closing price of the Company's common stock at the time such right is exercised. The unit's liquidation preference is the fair market value of the unit plus accrued distributions at the time of a liquidation event. Below is a summary of the activity relating to the preferred units in the Operating Partnership for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of period $ 166,501 $ 177,943 Issuance of preferred units — — Redemption of preferred units — (11,700) Dividends paid on preferred units (1,920) (6,271) Accrued dividends on preferred units 1,920 6,529 Balance at end of period $ 166,501 $ 166,501

Stockholders' Equity of the Com

Stockholders' Equity of the Company	3 Months Ended
	Mar. 31, 2024
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 March 31, 2024, 64,805,510 shares of common stock and no shares of excess stock were issued and outstanding. Share Repurchase Program In August 2016, our Board of Directors approved a $1.0 billion share repurchase program under which we can buy shares of our common stock. The Board of Directors has since authorized five separate $500.0 million increases to the size of the share repurchase program in the fourth quarter of 2017, second quarter of 2018, fourth quarter of 2018, fourth quarter of 2019, and fourth quarter of 2020 bringing the total program size to $3.5 billion. As of March 31, 2024, share repurchases executed under the program, excluding the redemption of OP units, were as follows: Period Shares repurchased Average price paid per share Cumulative number of shares repurchased as part of the repurchase plan or programs Year ended 2023 — $— 36,107,719 Three months ended March 31, 2024 — $— 36,107,719 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 any time, in whole or from time to time in part, at par for cash. 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 ("DRSPP") In February 2024, the Company filed a new 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 our 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 three months ended March 31, 2024 and 2023, respectively (dollars in thousands): Three Months Ended March 31, 2024 2023 Shares of common stock issued 1,662 5,280 Dividend reinvestments/stock purchases under the DRSPP $ 77 $ 184 Earnings per Share We use the two-class method of computing earnings per share (“EPS”), which is an earnings allocation formula that determines EPS for common stock and any participating securities according to dividends declared (whether paid or unpaid). Under the two-class method, basic EPS is computed by dividing the income available to common stockholders by the weighted-average number of common stock shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur from share equivalent activity. SL Green's earnings per share for the three months ended March 31, 2024 and 2023 are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Income (loss) attributable to SL Green common stockholders $ 13,141 $ (39,731) Less: distributed earnings allocated to participating securities (434) (406) Net income (loss) attributable to SL Green common stockholders (numerator for basic earnings per share) $ 12,707 $ (40,137) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Add back: effect of dilutive securities (redemption of units to common shares) 901 (2,837) Net income (loss) attributable to SL Green common stockholders (numerator for diluted earnings per share) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic Shares: Weighted average common stock outstanding 64,328 64,079 Effect of Dilutive Securities: Operating Partnership units redeemable for common shares 4,439 4,103 Stock-based compensation plans 1,328 — Diluted weighted average common stock outstanding 70,095 68,182 The Company has excluded 135,000 and 1,275,225 common stock equivalents from the calculation of diluted shares outstanding for the three months ended March 31, 2024 and 2023, respectively, as they were anti-dilutive. The Company is the sole managing general partner of the Operating Partnership and at March 31, 2024 owned 64,805,510 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 March 31, 2024, limited partners other than SL Green owned 6.38%, or 4,417,247 common units, of the Operating Partnership. Preferred Units Preferred units not owned by SL Green are further described in Note 11, “Noncontrolling Interests on the Company’s Consolidated Financial Statements - Preferred Units of Limited Partnership Interest in the Operating Partnership.” Earnings per Unit The Operating Partnership's earnings per unit for the three months ended March 31, 2024 and 2023, respectively, are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,068) Less: distributed earnings allocated to participating securities (434) (906) Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit) $ 13,608 $ (42,974) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic units: Weighted average common units outstanding 68,767 68,182 Effect of Dilutive Securities: Stock-based compensation plans 1,328 — Diluted weighted average common units outstanding 70,095 68,182 The Operating Partnership has excluded 135,000 and 1,275,225 common unit equivalents from the diluted units outstanding for the three months ended March 31, 2024 and 2023, respectively, as they were anti-dilutive. The following tables set forth the changes in accumulated other comprehensive income by component as of March 31, 2024 (in thousands): Net unrealized gain (loss) on derivative instruments ( 1 ) SL Green’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Net unrealized (loss) gain on marketable securities Total Balance at December 31, 2023 $ 25,352 $ (6,084) $ (1,791) $ 17,477 Other comprehensive income before reclassifications 29,023 5,409 1,019 35,451 Amounts reclassified from accumulated other comprehensive income (9,095) (3,682) — (12,777) Balance at March 31, 2024 $ 45,280 $ (4,357) $ (772) $ 40,151 (1) Amount reclassified from accumulated other comprehensive income is included in interest expense in the respective consolidated statements of operations. As of March 31, 2024 and December 31, 2023, the deferred net gains from these terminated hedges, which is included in accumulated other comprehensive income relating to net unrealized gain (loss) on derivative instruments, was ($0.3 million) and ($0.4 million), respectively. (2) Amount reclassified from accumulated other comprehensive income is included in equity in net income (loss) from unconsolidated joint ventures in the respective consolidated statements of operations.

Partners' Capital of the Operat

Partners' Capital of the Operating Partnership	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
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 March 31, 2024, 64,805,510 shares of common stock and no shares of excess stock were issued and outstanding. Share Repurchase Program In August 2016, our Board of Directors approved a $1.0 billion share repurchase program under which we can buy shares of our common stock. The Board of Directors has since authorized five separate $500.0 million increases to the size of the share repurchase program in the fourth quarter of 2017, second quarter of 2018, fourth quarter of 2018, fourth quarter of 2019, and fourth quarter of 2020 bringing the total program size to $3.5 billion. As of March 31, 2024, share repurchases executed under the program, excluding the redemption of OP units, were as follows: Period Shares repurchased Average price paid per share Cumulative number of shares repurchased as part of the repurchase plan or programs Year ended 2023 — $— 36,107,719 Three months ended March 31, 2024 — $— 36,107,719 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 any time, in whole or from time to time in part, at par for cash. 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 ("DRSPP") In February 2024, the Company filed a new 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 our 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 three months ended March 31, 2024 and 2023, respectively (dollars in thousands): Three Months Ended March 31, 2024 2023 Shares of common stock issued 1,662 5,280 Dividend reinvestments/stock purchases under the DRSPP $ 77 $ 184 Earnings per Share We use the two-class method of computing earnings per share (“EPS”), which is an earnings allocation formula that determines EPS for common stock and any participating securities according to dividends declared (whether paid or unpaid). Under the two-class method, basic EPS is computed by dividing the income available to common stockholders by the weighted-average number of common stock shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur from share equivalent activity. SL Green's earnings per share for the three months ended March 31, 2024 and 2023 are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Income (loss) attributable to SL Green common stockholders $ 13,141 $ (39,731) Less: distributed earnings allocated to participating securities (434) (406) Net income (loss) attributable to SL Green common stockholders (numerator for basic earnings per share) $ 12,707 $ (40,137) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Add back: effect of dilutive securities (redemption of units to common shares) 901 (2,837) Net income (loss) attributable to SL Green common stockholders (numerator for diluted earnings per share) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic Shares: Weighted average common stock outstanding 64,328 64,079 Effect of Dilutive Securities: Operating Partnership units redeemable for common shares 4,439 4,103 Stock-based compensation plans 1,328 — Diluted weighted average common stock outstanding 70,095 68,182 The Company has excluded 135,000 and 1,275,225 common stock equivalents from the calculation of diluted shares outstanding for the three months ended March 31, 2024 and 2023, respectively, as they were anti-dilutive. The Company is the sole managing general partner of the Operating Partnership and at March 31, 2024 owned 64,805,510 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 March 31, 2024, limited partners other than SL Green owned 6.38%, or 4,417,247 common units, of the Operating Partnership. Preferred Units Preferred units not owned by SL Green are further described in Note 11, “Noncontrolling Interests on the Company’s Consolidated Financial Statements - Preferred Units of Limited Partnership Interest in the Operating Partnership.” Earnings per Unit The Operating Partnership's earnings per unit for the three months ended March 31, 2024 and 2023, respectively, are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,068) Less: distributed earnings allocated to participating securities (434) (906) Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit) $ 13,608 $ (42,974) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic units: Weighted average common units outstanding 68,767 68,182 Effect of Dilutive Securities: Stock-based compensation plans 1,328 — Diluted weighted average common units outstanding 70,095 68,182 The Operating Partnership has excluded 135,000 and 1,275,225 common unit equivalents from the diluted units outstanding for the three months ended March 31, 2024 and 2023, respectively, as they were anti-dilutive. The following tables set forth the changes in accumulated other comprehensive income by component as of March 31, 2024 (in thousands): Net unrealized gain (loss) on derivative instruments ( 1 ) SL Green’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Net unrealized (loss) gain on marketable securities Total Balance at December 31, 2023 $ 25,352 $ (6,084) $ (1,791) $ 17,477 Other comprehensive income before reclassifications 29,023 5,409 1,019 35,451 Amounts reclassified from accumulated other comprehensive income (9,095) (3,682) — (12,777) Balance at March 31, 2024 $ 45,280 $ (4,357) $ (772) $ 40,151 (1) Amount reclassified from accumulated other comprehensive income is included in interest expense in the respective consolidated statements of operations. As of March 31, 2024 and December 31, 2023, the deferred net gains from these terminated hedges, which is included in accumulated other comprehensive income relating to net unrealized gain (loss) on derivative instruments, was ($0.3 million) and ($0.4 million), respectively. (2) Amount reclassified from accumulated other comprehensive income is included in equity in net income (loss) from unconsolidated joint ventures in the respective consolidated statements of operations.

Share-based Compensation

Share-based Compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Share-based Compensation	Share-based Compensation We have share-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. The Fifth Amended and Restated 2005 Stock Option and Incentive Plan, or the 2005 Plan, was approved by the Company's Board of Directors in April 2022 and its stockholders in June 2022 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, cash-based awards and other equity-based awards. Subject to adjustments upon certain corporate transactions or events, awards with respect to up to a maximum of 32,210,000 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 2.59 Fungible Units per share subject to such awards, (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 0.84 fungible units per share subject to such awards, and (3) all other awards (e.g., 10-year stock options) counting as 1.0 fungible units per share subject to such awards. Awards granted under the 2005 Plan prior to the approval of the fifth amendment and restatement in June 2022 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 32,210,000 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 our 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 1, 2032, which is the tenth anniversary of the date that the 2005 Plan was most recently approved by the Company's stockholders. As of March 31, 2024, 3.0 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. Stock Options and Class O LTIP Units Options are granted with an exercise price at the fair market value of the Company's common stock on the date of grant and, subject to employment, generally expire five years or ten years from the date of grant, are not transferable other than on death, and generally vest in one year to five years commencing one year from the date of grant. We have also granted Class O LTIP Units, which are a class of LTIP Units in the Operating Partnership structured to provide economics similar to those of stock options. Class O LTIP Units, once vested, may be converted, at the election of the holder, into a number of common units of the Operating Partnership per Class O LTIP Unit determined by the increase in value of a share of the Company’s common stock at the time of conversion over a participation threshold, which equals the fair market value of a share of the Company’s common stock at the time of grant. Class O LTIP Units are entitled to distributions, subject to vesting, equal per unit to 10% of the per unit distributions paid with respect to the common units of the Operating Partnership. The fair value of each stock option or LTIP Unit granted is estimated on the date of grant using the Black-Scholes option pricing model based on historical information. There were no options granted during the three months ended March 31, 2024 or the year ended December 31, 2023. A summary of the status of the Company's stock options as of March 31, 2024 and December 31, 2023, and changes during the three months ended March 31, 2024 and year ended December 31, 2023 are as follows: March 31, 2024 December 31, 2023 Options Outstanding Weighted Average Options Outstanding Weighted Average Balance at beginning of period 115,980 $ 103.52 313,480 $ 97.59 Exercised — — — — Lapsed or canceled — — (197,500) 84.14 Balance at end of period 115,980 $ 103.52 115,980 $ 103.52 Options exercisable at end of period 115,980 $ 103.52 115,980 $ 103.52 The remaining weighted average contractual life of the options outstanding was 2.7 years and the remaining average contractual life of the options exercisable was 2.7 years. During the three months ended March 31, 2024, we recognized no compensation expense related to options. During the three months ended March 31, 2023, we recognized no compensation expense related to options. As of March 31, 2024, there was no unrecognized compensation cost related to unvested stock options. Restricted Shares Shares may be granted to certain employees, including our executives, and vesting occurs upon the completion of a service period or our meeting established financial performance criteria. Vesting occurs at rates ranging from 15% to 35% once performance criteria are reached. A summary of the Company's restricted stock as of March 31, 2024 and December 31, 2023 and changes during the three months ended March 31, 2024 and the year ended December 31, 2023, are as follows: March 31, 2024 December 31, 2023 Balance at beginning of period 4,089,174 3,758,174 Granted 3,234 337,350 Canceled (7,450) (6,350) Balance at end of period 4,084,958 4,089,174 Vested during the period 134,620 147,915 Compensation expense recorded $ 2,625,319 $ 7,766,055 Total fair value of restricted stock granted during the period $ 151,901 $ 15,789,540 The fair value of restricted stock that vested during the three months ended March 31, 2024 and the year ended December 31, 2023 was $7.1 million and $10.2 million, respectively. As of March 31, 2024, there was $17.3 million of total unrecognized compensation cost related to restricted stock, which is expected to be recognized over a weighted average period of 2.2 years. We granted LTIP Units, which include bonus, time-based and performance-based awards, with a fair value of $23.7 million and $38.1 million as of March 31, 2024 and December 31, 2023, respectively. The grant date fair value of the LTIP Unit awards was calculated in accordance with ASC 718. A third-party consultant determined that the fair value of the LTIP Units has a discount to our 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 March 31, 2024, there was $42.1 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 1.8 years. During the three months ended March 31, 2024, we recorded compensation expense related to bonus, time-based and performance-based awards of $6.2 million. During the three months ended March 31, 2023, we recorded compensation expense related to bonus, time-based and performance-based awards of $10.0 million. For the three months ended March 31, 2024, $0.3 million was capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options. For the three months ended March 31, 2023, $0.4 million was capitalized to assets associated with compensation expense related to our long-term compensation plans, restricted stock and stock options. 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 our 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 three months ended March 31, 2024, 15,945 phantom stock units and 25,590 shares of common stock were issued to our Board of Directors. We recorded compensation expense of $2.1 million and $2.1 million during the three months ended March 31, 2024 and 2023, respectively, related to the Deferred Compensation Plan. As of March 31, 2024, there were 125,654 phantom stock units outstanding pursuant to our Non-Employee Director's Deferral Program. Employee Stock Purchase Plan

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Accumulated Other Comprehensive Income	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 March 31, 2024, 64,805,510 shares of common stock and no shares of excess stock were issued and outstanding. Share Repurchase Program In August 2016, our Board of Directors approved a $1.0 billion share repurchase program under which we can buy shares of our common stock. The Board of Directors has since authorized five separate $500.0 million increases to the size of the share repurchase program in the fourth quarter of 2017, second quarter of 2018, fourth quarter of 2018, fourth quarter of 2019, and fourth quarter of 2020 bringing the total program size to $3.5 billion. As of March 31, 2024, share repurchases executed under the program, excluding the redemption of OP units, were as follows: Period Shares repurchased Average price paid per share Cumulative number of shares repurchased as part of the repurchase plan or programs Year ended 2023 — $— 36,107,719 Three months ended March 31, 2024 — $— 36,107,719 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 any time, in whole or from time to time in part, at par for cash. 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 ("DRSPP") In February 2024, the Company filed a new 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 our 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 three months ended March 31, 2024 and 2023, respectively (dollars in thousands): Three Months Ended March 31, 2024 2023 Shares of common stock issued 1,662 5,280 Dividend reinvestments/stock purchases under the DRSPP $ 77 $ 184 Earnings per Share We use the two-class method of computing earnings per share (“EPS”), which is an earnings allocation formula that determines EPS for common stock and any participating securities according to dividends declared (whether paid or unpaid). Under the two-class method, basic EPS is computed by dividing the income available to common stockholders by the weighted-average number of common stock shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur from share equivalent activity. SL Green's earnings per share for the three months ended March 31, 2024 and 2023 are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Income (loss) attributable to SL Green common stockholders $ 13,141 $ (39,731) Less: distributed earnings allocated to participating securities (434) (406) Net income (loss) attributable to SL Green common stockholders (numerator for basic earnings per share) $ 12,707 $ (40,137) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Add back: effect of dilutive securities (redemption of units to common shares) 901 (2,837) Net income (loss) attributable to SL Green common stockholders (numerator for diluted earnings per share) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic Shares: Weighted average common stock outstanding 64,328 64,079 Effect of Dilutive Securities: Operating Partnership units redeemable for common shares 4,439 4,103 Stock-based compensation plans 1,328 — Diluted weighted average common stock outstanding 70,095 68,182 The Company has excluded 135,000 and 1,275,225 common stock equivalents from the calculation of diluted shares outstanding for the three months ended March 31, 2024 and 2023, respectively, as they were anti-dilutive. The Company is the sole managing general partner of the Operating Partnership and at March 31, 2024 owned 64,805,510 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 March 31, 2024, limited partners other than SL Green owned 6.38%, or 4,417,247 common units, of the Operating Partnership. Preferred Units Preferred units not owned by SL Green are further described in Note 11, “Noncontrolling Interests on the Company’s Consolidated Financial Statements - Preferred Units of Limited Partnership Interest in the Operating Partnership.” Earnings per Unit The Operating Partnership's earnings per unit for the three months ended March 31, 2024 and 2023, respectively, are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,068) Less: distributed earnings allocated to participating securities (434) (906) Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit) $ 13,608 $ (42,974) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic units: Weighted average common units outstanding 68,767 68,182 Effect of Dilutive Securities: Stock-based compensation plans 1,328 — Diluted weighted average common units outstanding 70,095 68,182 The Operating Partnership has excluded 135,000 and 1,275,225 common unit equivalents from the diluted units outstanding for the three months ended March 31, 2024 and 2023, respectively, as they were anti-dilutive. The following tables set forth the changes in accumulated other comprehensive income by component as of March 31, 2024 (in thousands): Net unrealized gain (loss) on derivative instruments ( 1 ) SL Green’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Net unrealized (loss) gain on marketable securities Total Balance at December 31, 2023 $ 25,352 $ (6,084) $ (1,791) $ 17,477 Other comprehensive income before reclassifications 29,023 5,409 1,019 35,451 Amounts reclassified from accumulated other comprehensive income (9,095) (3,682) — (12,777) Balance at March 31, 2024 $ 45,280 $ (4,357) $ (772) $ 40,151 (1) Amount reclassified from accumulated other comprehensive income is included in interest expense in the respective consolidated statements of operations. As of March 31, 2024 and December 31, 2023, the deferred net gains from these terminated hedges, which is included in accumulated other comprehensive income relating to net unrealized gain (loss) on derivative instruments, was ($0.3 million) and ($0.4 million), respectively. (2) Amount reclassified from accumulated other comprehensive income is included in equity in net income (loss) from unconsolidated joint ventures in the respective consolidated statements of operations.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We are required to disclose fair value information with regard to certain of 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 certain 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 as of March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 Total Level 1 Level 2 Level 3 Assets: Marketable securities available-for-sale $ 10,673 $ — $ 10,673 $ — Interest rate cap and swap agreements (included in Other assets) 51,388 — 51,388 — Liabilities: Interest rate cap and swap agreements (included in Other liabilities) $ 7,754 $ — $ 7,754 $ — December 31, 2023 Total Level 1 Level 2 Level 3 Assets: Marketable securities available-for-sale $ 9,591 $ — $ 9,591 $ — Interest rate cap and swap agreements (included in Other assets) 33,456 — 33,456 — Liabilities: Interest rate cap and swap agreements (included in Other liabilities) $ 17,108 $ — $ 17,108 $ — We evaluate real estate investments and debt and preferred equity investments, including intangibles, for potential impairment primarily utilizing cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, as well as sales comparison approach, which utilizes comparable sales, listings and sales contracts, all of which are classified as Level 3 inputs. In March 2024, the Company entered into an agreement to acquire its partner's 45.0% interest in the 10 East 53rd Street joint venture. As a result of the contract terms, it was concluded that the joint venture is a VIE in which the Company is the primary beneficiary, and the investment was consolidated in our financial statements. Upon consolidating the entity, the assets and liabilities of the entity were recorded at fair value which resulted in the recognition of a fair value adjustment of ($55.7 million), which is included in Purchase price and other fair value adjustments in the consolidated statements of operations. This fair value was determined using a third-party valuation which primarily utilized cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, as well as the sales comparison approach, which utilizes comparable sales, listings, and sales contracts. All of which are classified as Level 3 inputs. Marketable securities classified as Level 1 are derived from quoted prices in active markets. The valuation technique used to measure the fair value of 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. 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 instrument 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 March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Carrying Value (1) Fair Value Carrying Value (1) Fair Value Debt and preferred equity investments $ 352,347 (2) $ 346,745 (2) Fixed rate debt $ 3,040,885 $ 2,973,363 $ 3,237,386 $ 3,184,338 Variable rate debt (3) 760,493 759,604 270,000 268,787 $ 3,801,378 $ 3,732,967 $ 3,507,386 $ 3,453,125 (1) Amounts exclude net deferred financing costs. (2) As of March 31, 2024, debt and preferred equity investments had an estimated fair value of approximately $0.3 billion. As of December 31, 2023, debt and preferred equity investments had an estimated fair value of approximately $0.3 billion. (3) As of March 31, 2024, variable rate debt with a carrying value of $110.5 million and fair value of $109.4 million is included in the Company's alternative strategy portfolio. Disclosures regarding fair value of financial instruments was based on pertinent information available to us as of March 31, 2024 and December 31, 2023. 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	3 Months Ended
	Mar. 31, 2024
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, including, but not limited to, interest rate swaps, caps, collars 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 sheet 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 (loss) until the hedged item is 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 as of March 31, 2024 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 (dollars in thousands). Notional Strike Effective Expiration Balance Sheet Location Fair Interest Rate Cap 370,000 3.250 % June 2023 June 2024 Other Assets $ 1,565 Interest Rate Cap 370,000 3.250 % June 2023 June 2024 Other Liabilities (1,562) Interest Rate Cap 220,000 4.000 % February 2024 February 2025 Other Assets 1,789 Interest Rate Swap 150,000 2.621 % December 2021 January 2026 Other Assets 4,915 Interest Rate Swap 200,000 2.662 % December 2021 January 2026 Other Assets 6,417 Interest Rate Swap 100,000 2.903 % February 2023 February 2027 Other Assets 3,528 Interest Rate Swap 100,000 2.733 % February 2023 February 2027 Other Assets 3,983 Interest Rate Swap 50,000 2.463 % February 2023 February 2027 Other Assets 2,354 Interest Rate Swap 200,000 2.591 % February 2023 February 2027 Other Assets 8,730 Interest Rate Swap 300,000 2.866 % July 2023 May 2027 Other Assets 11,314 Interest Rate Swap 150,000 3.524 % January 2024 May 2027 Other Assets 2,794 Interest Rate Swap 370,000 3.888 % November 2022 June 2027 Other Assets 2,879 Interest Rate Swap (1) 300,000 4.487 % November 2024 November 2027 Other Liabilities (5,113) Interest Rate Swap 100,000 3.756 % January 2023 January 2028 Other Assets 1,120 Interest Rate Swap 204,963 3.915 % February 2025 May 2028 Other Liabilities (1,079) $ 43,634 (1) Quarterly changes in fair value recognized in the calculation of FFO. During the three months ended March 31, 2024, we recorded a gain of $5.2 million based on the changes in the fair value of a forward-starting interest rate swap, which is included in Purchase price and other fair value adjustments in the consolidated statements of operations. During the three months ended March 31, 2023, we recorded a gain of $0.2 million based on the changes in the fair value of an interest rate cap we sold, which is included in Purchase price and other fair value adjustments in the consolidated statements of operations. During the three months ended March 31, 2024, we recorded a loss of less than $0.1 million on the changes in fair value, which is included in interest expense in the consolidated statements of operations. During the three months ended March 31, 2023, we recorded a loss of $0.1 million on the changes in fair value, which is included in interest expense in the consolidated statements of operations. Certain agreements the Company has with each of its derivative counterparties contain a provision where if the Company defaults on any of its indebtedness, then the Company could also be declared in default on its derivative obligations. As of March 31, 2024, 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 ($8.1 million). As of March 31, 2024, the Company was not required to post 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 $8.5 million as of March 31, 2024. Gains and losses on terminated hedges are included in accumulated other comprehensive income, and are recognized into earnings over the term of the related obligation. Over time, the realized and unrealized gains and losses held in accumulated other comprehensive income 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 ($32.8 million) of the current balance held in accumulated other comprehensive income will be reclassified into interest expense and ($7.3 million) of the portion related to our share of joint venture accumulated other comprehensive income will be reclassified into equity in net loss from unconsolidated joint ventures within the next 12 months. The following table presents the effect of our derivative financial instruments and our share of our joint ventures' derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the three months ended March 31, 2024 and 2023, respectively (in thousands): Amount of Gain Recognized in Location of Gain Reclassified from Accumulated Other Comprehensive Income into Income Amount of Gain Reclassified from Three Months Ended March 31, Three Months Ended March 31, Derivative 2024 2023 2024 2023 Interest Rate Swaps/Caps $ 31,156 $ (17,913) Interest expense $ 9,763 $ 9,023 Share of unconsolidated joint ventures' derivative instruments 5,705 (1,495) Equity in net loss from unconsolidated joint ventures 3,884 2,628 $ 36,861 $ (19,408) $ 13,647 $ 11,651 The following table summarizes the notional value at inception and fair value of our joint ventures' derivative financial instruments as of March 31, 2024 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 (dollars in thousands). Notional Strike Effective Expiration Classification Fair Interest Rate Cap $ 501,650 0.490 % February 2022 May 2024 Asset $ 2,560 Interest Rate Cap 501,650 0.490 % February 2022 May 2024 Asset 2,560 Interest Rate Cap 505,412 3.000 % June 2023 June 2024 Asset 2,490 Interest Rate Cap 273,616 4.000 % August 2023 August 2024 Asset 1,212 Interest Rate Cap 514,897 3.500 % September 2023 September 2024 Asset 4,118 Interest Rate Cap 278,161 4.000 % May 2024 November 2024 Asset 1,624 Interest Rate Cap 278,161 4.000 % May 2024 November 2024 Asset 1,624 Interest Rate Swap 250,000 3.608 % April 2023 February 2026 Asset 4,070 Interest Rate Swap 250,000 3.608 % April 2023 February 2026 Asset 4,069 Interest Rate Swap 177,000 1.555 % December 2022 February 2026 Asset 9,459 $ 33,786

Lease Income

Lease Income	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Lease Income	Lease Income The Operating Partnership is the lessor and the sublessor to tenants under operating and sales-type leases. The minimum rental amounts due under the leases are generally 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. The components of lease income from operating leases during the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three Months Ended March 31, 2024 2023 Fixed lease payments $ 128,252 $ 166,353 Variable lease payments 13,301 20,450 Total lease payments (1) $ 141,553 $ 186,803 Amortization of acquired above and below-market leases (49) 8,239 Total rental revenue $ 141,504 $ 195,042 (1) Amounts include $48.4 million and $48.9 million of sublease income during the three months ended March 31, 2024 and 2023, respectively. The components of lease income from sales-type leases during the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three Months Ended March 31, 2024 2023 Interest income (1) $ 1,120 $ 1,106 (1) These amounts are included in Other income in our consolidated statements of operations.
Lease Income	Lease Income The Operating Partnership is the lessor and the sublessor to tenants under operating and sales-type leases. The minimum rental amounts due under the leases are generally 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. The components of lease income from operating leases during the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three Months Ended March 31, 2024 2023 Fixed lease payments $ 128,252 $ 166,353 Variable lease payments 13,301 20,450 Total lease payments (1) $ 141,553 $ 186,803 Amortization of acquired above and below-market leases (49) 8,239 Total rental revenue $ 141,504 $ 195,042 (1) Amounts include $48.4 million and $48.9 million of sublease income during the three months ended March 31, 2024 and 2023, respectively. The components of lease income from sales-type leases during the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three Months Ended March 31, 2024 2023 Interest income (1) $ 1,120 $ 1,106 (1) These amounts are included in Other income in our consolidated statements of operations.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings As of March 31, 2024, 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. 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.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Segment Information	Segment Information The Company has three reportable segments, real estate, debt and preferred equity investments, and SUMMIT. In the fourth quarter of 2023, due to quantitative thresholds, SUMMIT was identified as a reportable segment. As such, prior period segment data has been restated to reflect SUMMIT as a reportable segment for comparative purposes. We evaluate real estate performance and allocate resources based on earnings contributions. The primary sources of revenue are generated from tenant rents, escalations and reimbursement revenue. Real estate property operating expenses consist primarily of security, maintenance, utility costs, insurance, real estate taxes and, at certain properties, ground rent expense. See Note 5, "Debt and Preferred Equity Investments," for additional details on our debt and preferred equity investments. SUMMIT currently operates one location at One Vanderbilt Avenue in midtown Manhattan with the primary source of revenue generated from ticket sales. Selected consolidated results of operations for the three months ended March 31, 2024 and 2023, and selected asset information as of March 31, 2024 and December 31, 2023, regarding our operating segments are as follows (in thousands): Real Estate Segment SUMMIT Segment Debt and Preferred Equity Segment Total Company Total revenues Three months ended: March 31, 2024 $ 154,875 $ 25,604 $ 7,403 $ 187,882 March 31, 2023 $ 216,936 $ 19,771 $ 9,057 $ 245,764 Net income (loss) Three months ended: March 31, 2024 $ 12,727 $ 4,453 $ 1,209 $ 18,389 March 31, 2023 $ (42,883) $ (2,418) $ 6,944 $ (38,357) Total assets As of: March 31, 2024 $ 8,946,952 $ 465,787 $ 351,553 $ 9,764,292 December 31, 2023 $ 8,716,738 $ 464,799 $ 349,644 $ 9,531,181 We 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 to the debt and preferred equity segment because that segment does not have dedicated personnel and the use of personnel and resources is dependent on transaction volume between the three segments, which varies between periods. In addition, we base performance on the individual segments prior to allocating marketing, general and administrative expenses. SUMMIT segment incurs its own marketing, general and administrative expenses for its dedicated personnel, which are included in SUMMIT Operator expenses in the consolidated statement of operations. For the three months ended March 31, 2024, marketing, general and administrative expenses totaled $21.3 million. For the three months ended March 31, 2023, marketing, general and administrative expenses totaled $23.3 million. All other expenses, except interest and SUMMIT operator expenses, relate entirely to the real estate assets. There were no transactions between the above three segments other than the SUMMIT lease with our One Vanderbilt Avenue joint venture, which is part of the real estate segment. See Note 10, "Related Party Transactions."

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
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. 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 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.
Investment in Commercial Real Estate Properties	Investment in Commercial Real Estate Properties 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 3 years 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 1 year to 15 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 1 year to 15 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. Origination costs are amortized as an expense over the remaining life of the lease and tenant improvements are amortized over the shorter of the remaining life of the lease or useful life of the improvement (or charged against earnings if the lease is terminated prior to its contractual expiration date). When allocating the purchase price of real estate, we assess fair value of the leases based on estimated cash flow projections that utilize appropriate discount 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. The Company classifies those leases under which the Company is the lessee at lease commencement as finance or operating leases. Leases qualify as finance leases if the lease transfers ownership of the asset at the end of the lease term, the lease grants an option to purchase the asset that we are reasonably certain to exercise, the lease term is for a major part of the remaining economic life of the asset, or the present value of the lease payments exceeds substantially all of the fair value of the asset. Leases that do not qualify as finance leases are deemed to be operating leases. At lease commencement the Company records a lease liability which is measured as the present value of the lease payments and a right of use asset which is measured as the amount of the lease liability and any initial direct costs incurred. The Company applies a discount rate to determine the present value of the lease payments. If the rate implicit in the lease is known, the Company uses that rate. If the rate implicit in the lease is not known, the Company uses a discount rate reflective of the Company’s collateralized borrowing rate given the term of the lease. To determine the discount rate, the Company employs a third party specialist to develop an analysis based primarily on the observable borrowing rates of the Company, other REITs, and other corporate borrowers with long-term borrowings. On the consolidated statements of operations, operating leases are expensed through operating lease rent while financing leases are expensed through amortization and interest expense. When applicable, the Company combines the consideration for lease and non-lease components in the calculation of the value of the lease obligation and right-of-use asset.
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.
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.
Investment in Marketable Securities	Investment in Marketable Securities At acquisition, we designate a debt security as held-to-maturity, available-for-sale, or trading. As of March 31, 2024, we did not have any debt securities designated as held-to-maturity or trading. We account for our available-for-sale securities at fair value pursuant to ASC 820-10, with the net unrealized gains or losses reported as a component of accumulated other comprehensive income or loss. The cost of marketable securities sold and the amount reclassified out of accumulated other comprehensive income into earnings is determined using the specific identification method. Credit losses are recognized in accordance with ASC 326. We account for equity marketable securities at fair value pursuant to ASC 820-10, with the net unrealized gains or losses reported in net income.
Investments in Unconsolidated Joint Ventures	Investments in Unconsolidated Joint Ventures We assess our investments in unconsolidated joint ventures for recoverability and if it is determined that a loss in value of the investment is other than temporary, we write down the investment to its fair value. We evaluate our equity investments for impairment based on each joint ventures' actual and projected cash flows. Aside from charges noted in Note 6, "Investments in Unconsolidated Joint Ventures," we do not believe that the values of any of our equity investments were impaired at March 31, 2024.
Deferred Lease Costs and Lease Classification	Deferred Lease Costs Deferred lease costs consist of incremental fees and direct costs that would not have been incurred if the lease had not been obtained and are amortized on a straight-line basis over the related lease term. Lease Classification Lease classification for leases under which the Company is the lessor is evaluated at lease commencement and leases not classified as sales-type leases or direct financing leases are classified as operating leases. Leases qualify as sales-type leases if the contract includes either transfer of ownership clauses, certain purchase options, a lease term representing a major part of the economic life of the asset, or the present value of the lease payments and residual guarantees provided by the lessee exceeds substantially all of the fair value of the asset. Additionally, leasing an asset so specialized that it is not deemed to have any value to the Company at the end of the lease term may also result in classification as a sales-type lease. Leases qualify as direct financing leases when the present value of the lease payments and residual value guarantees provided by the lessee and unrelated third parties exceeds substantially all of the fair value of the asset and collection of the payments is probable.
Revenue Recognition	Revenue Recognition Rental revenue for operating leases is recognized on a straight-line basis over the term of the lease. Rental revenue recognition commences when the leased space is available for its intended use by the lessee. To determine whether the leased space is available for its intended use by the lessee, management evaluates whether we or the tenant are 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 of tenant improvements, rental revenue recognition begins when the tenant takes possession of or controls the space. 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. In addition to base rent, our tenants also generally will pay variable rent, which represents their pro rata share of increases in real estate taxes and certain operating expenses for the building over a base year. In some leases, in lieu of paying additional rent based upon increases in certain 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. Rental revenue is recognized if collectability is probable. If collectability of substantially all of the lease payments is assessed as not probable, any difference between the rental revenue recognized to date and the lease payments that have been collected is recognized as a current-period adjustment to rental revenue. A subsequent change in the assessment of collectability to probable may result in a current-period adjustment to rental revenue for any difference between the rental revenue that would have been recognized if collectability had always been assessed as probable and the rental revenue recognized to date. The Company provides its tenants with certain customary services for lease contracts such as common area maintenance and general security. We have elected to combine the non-lease components with the lease components of our operating lease agreements and account for them as a single lease component in accordance with ASC 842. We record a gain or loss on sale of real estate assets when we no longer have a controlling financial interest in the entity owning the real estate, a contract exists with a third party and that third party has control of the assets acquired. Investment income on debt and preferred equity investments is accrued based on the contractual terms of the instruments and when 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 collectible. 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 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 cash flows 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. We consider a debt and preferred equity investment to be past due when amounts contractually due have not been paid. 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 is resumed on any debt or preferred equity investment that is on non-accrual status when such debt or preferred equity investment becomes contractually current and performance is demonstrated to be resumed. 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 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 operations. 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. Revenues from the sale of SUMMIT tickets are recognized upon admission or ticket expirations. Deferred revenue related to unused and unexpired tickets as of March 31, 2024 and 2023 was $4.2 million and $3.2 million, respectively, and is included in Deferred revenue on the consolidated balance sheets.
Debt and Preferred Equity Investments	Debt and Preferred Equity Investments Debt and preferred equity investments are presented at the net amount expected to be collected in accordance with ASC 326. An allowance for loan losses is deducted from the amortized cost basis of the financial assets to present the net carrying value at the amount expected to be collected through the expected maturity date of such investments. The expense for loan loss and other investment reserves is the charge to earnings to adjust the allowance for loan losses to the appropriate level. Amounts are written off from the allowance when we de-recognize the related investment either as a result of a sale of the investment or acquisition of equity interests in the collateral. The Company evaluates the amount expected to be collected based on current market and economic conditions, historical loss information, and reasonable and supportable forecasts. The Company's assumptions are derived from both internal data and external data which may include, among others, governmental economic projections for the New York City Metropolitan area, public data on recent transactions and filings for securitized debt instruments. This information is aggregated by asset class and adjusted for duration. Based on these inputs, loans are evaluated at the individual asset level. In certain instances, we may also use a probability-weighted model that considers the likelihood of multiple outcomes and the amount expected to be collected for each outcome. The evaluation of the possible credit deterioration associated with the performance and/or value of the underlying collateral property as well as the financial and operating capability of the borrower/sponsor requires significant judgment, which include both asset level and market assumptions over the relevant time period. In addition, quarterly, the Company assigns each loan a risk rating. Based on a 3-point scale, loans are rated “1” through “3,” from lower risk to higher risk, which ratings are defined as follows: 1 - Low Risk Assets - Low probability of loss, 2 - Watch List Assets - Higher potential for loss, 3 - High Risk Assets - Loss more likely than not. Loans with risk ratings of 2 or above are evaluated to determine whether the expected risk of loss is appropriately captured through the combination of our expectations of current conditions, historical loss information and supportable forecasts described above or whether risk characteristics specific to the loan warrant the use of a probability-weighted model. Financing investments that are classified as held for sale are carried at the expected amount to be collected 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 expected amount to be collected. Other financing receivables that are included in balance sheet line items other than the Debt and preferred equity investments line are also measured at the net amount expected to be collected. Accrued interest receivable amounts related to these debt and preferred equity investment and other financing receivables are recorded at the net amount expected to be collected within Other assets in the consolidated balance sheets. Accrued interest receivables that are written off are recognized as an expense in loan loss and other investment reserves.
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 its 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 its 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. We have elected, and may elect in the future, to treat certain of our 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, state and local corporate tax liability for these entities. During the three months ended March 31, 2024 and 2023, we recorded Federal, state and local tax provisions totaling $0.7 million and $0.8 million, respectively, for these entities. SUMMIT is also held in a TRS and pays Federal, state and local taxes. During the quarter ended March 31, 2024, we recorded Federal, state and local tax benefit for SUMMIT of $1.3 million. During the quarter ended March 31, 2023, we recorded Federal, state and local tax expense for SUMMIT of $1.3 million. 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.
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 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."
Reclassification	Reclassification Certain prior year balances have been reclassified to conform to our current year presentation.
Accounting Standards Updates	Accounting Standards Updates In December 2023, the FASB issued ASU No. 2023-09 Income Taxes (Topic 740) - Improvements to Income Tax Disclosures. The objective of the amendments in ASU 2023-09 related to the rate reconciliation and income taxes paid disclosures are to improve transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. The amendment will require that public entities on an annual basis disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold. Additionally, the amendment will require that all entities disclose on an annual basis the amount of taxes paid (net of refunds received) disaggregated by federal, state and foreign taxes as well as disaggregated by individual jurisdictions that meet a quantitative threshold. ASU 2023-09 is effective prospectively for annual periods beginning after December 15, 2024. Early adoption and retrospective application is permitted. We are currently evaluating the impact of the adoption of ASU 2023-09 on our consolidated financial statements, but do not believe the adoption of this standard will have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU No. 2023-07 Segment Reporting (Topic 280) - Improvements to Reportable Segment Disclosures. ASU 2023-07 amends the reportable segment disclosure requirements to enhance disclosures about significant segment expenses. The objective of the amendment is to improve financial reporting by requiring disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. The amendment will require that a public entity disclose, on an annual and interim basis, significant segment expenses that are regularly provided to the chief operating decision maker ("CODM") and included within each reported measure of segment profit or loss (collectively referred to as the "significant expense principle"). Additionally, the amendment will require an entity to disclose an amount for "other segment items" by reportable segment and a description of its composition as well as require annual disclosures about a reportable segment's profit or loss and assets currently required by Topic 280 in interim periods. Lastly, the amendment will require a public entity to disclose the title and position of the CODM and an explanation of how the CODM uses the reported measures of segment profit or loss in assessing segment performance and deciding to allocate resources. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted and should be applied retrospectively to all prior periods presented in the financial statements. We are currently evaluating the impact of the adoption of ASU 2023-07 on our consolidated financial statements, but do not believe the adoption of this standard will have a material impact on our consolidated financial statements. In August 2023, the FASB issued ASU No. 2023-05 Business Combinations - Joint Venture Formations (Subtopic 805-60) Recognition and Initial Measurement. ASU 2023-05 addresses the accounting for contributions made to a joint venture, upon formation, in a joint venture's separate financial statements. The objectives of the amendments are to provide decision-useful information to investors and other allocators of capital in a joint venture's financial statements and reduce diversity in practice. The amendments require that a joint venture apply the following key adaptations from the business combinations guidance upon formation: (i) a joint venture is the formation of a new entity without an accounting acquirer, (ii) a joint venture measures its identifiable net assets and goodwill, if any, at the formation date, (iii) initial measurement of a joint venture's total net assets is equal to the fair value of 100 percent of the joint venture's equity, and (iv) a joint venture provides relevant disclosures. ASU 2023-05 is effective prospectively for all joint venture formations with a formation date on or after January 1, 2025, with early adoption permitted in any interim or annual period in which financial statements have not yet been issued, either prospectively or retrospectively. We are currently evaluating the impact of the adoption of ASU 2023-05 on our consolidated financial statements, but do not believe the adoption of this standard will have a material impact on our consolidated financial statements.
Fair Value Measurements	Fair Value Measurements We are required to disclose fair value information with regard to certain of 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 certain 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. We evaluate real estate investments and debt and preferred equity investments, including intangibles, for potential impairment primarily utilizing cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, as well as sales comparison approach, which utilizes comparable sales, listings and sales contracts, all of which are classified as Level 3 inputs. In March 2024, the Company entered into an agreement to acquire its partner's 45.0% interest in the 10 East 53rd Street joint venture. As a result of the contract terms, it was concluded that the joint venture is a VIE in which the Company is the primary beneficiary, and the investment was consolidated in our financial statements. Upon consolidating the entity, the assets and liabilities of the entity were recorded at fair value which resulted in the recognition of a fair value adjustment of ($55.7 million), which is included in Purchase price and other fair value adjustments in the consolidated statements of operations. This fair value was determined using a third-party valuation which primarily utilized cash flow projections that apply, among other things, estimated revenue and expense growth rates, discount rates and capitalization rates, as well as the sales comparison approach, which utilizes comparable sales, listings, and sales contracts. All of which are classified as Level 3 inputs. Marketable securities classified as Level 1 are derived from quoted prices in active markets. The valuation technique used to measure the fair value of 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. 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 instrument to their present value using adjusted market interest rates, which is provided by a third-party specialist.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Commercial Office Properties	On March 31, 2024, we owned the following interests in properties in the New York metropolitan area, primarily in midtown Manhattan. Our investments located outside of Manhattan are referred to as the Suburban properties: Consolidated Unconsolidated Total Location Property Number of Buildings Approximate Square Feet (unaudited) Number of Buildings Approximate Square Feet (unaudited) Number of Buildings Approximate Square Feet (unaudited) Weighted Average Leased Occupancy (1) (unaudited) Commercial: Manhattan Office 14 8,753,441 10 13,009,149 24 21,762,590 88.6 % Retail 1 22,648 1 12,946 2 35,594 100.0 % Development/Redevelopment 2 (2) 880,771 2 1,959,426 4 2,840,197 N/A 17 9,656,860 13 14,981,521 30 24,638,381 88.6 % Suburban Office 7 862,800 — — 7 862,800 73.8 % Total commercial properties 24 10,519,660 13 14,981,521 37 25,501,181 88.0 % Residential: Manhattan Residential 1 (2) 140,382 1 221,884 2 362,266 99.6 % Total core portfolio 25 10,660,042 14 15,203,405 39 25,863,447 88.2 % Alternative Strategy Portfolio 2 17,888 8 3,694,956 10 3,712,844 66.1 % (1) The weighted average leased occupancy for commercial properties represents the total leased square footage divided by the total square footage at acquisition. The weighted average leased for residential properties represents the total leased units divided by the total available units. Properties under construction are not included in the calculation of weighted average leased occupancy. (2) As of March 31, 2024, we owned a building at 7 Dey Street / 185 Broadway that was comprised of approximately 140,382 square feet (unaudited) of residential space and approximately 50,206 square feet (unaudited) of office and retail space that is under development. For the purpose of this report, we have included this building in the number of residential properties we own. However, we have included only the residential square footage in the residential approximate square footage, and have listed the balance of the square footage as development square footage.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Schedule of Identified Intangible Assets and Intangible Liabilities	The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Identified intangible assets (included in other assets): Gross amount $ 273,010 $ 189,680 Accumulated amortization (185,470) (184,902) Net $ 87,540 $ 4,778 Identified intangible liabilities (included in deferred revenue): Gross amount $ 226,034 $ 205,394 Accumulated amortization (202,178) (202,089) Net $ 23,856 $ 3,305
Schedule of Marketable Securities	As of March 31, 2024 and December 31, 2023, we held the following marketable securities (in thousands): March 31, 2024 December 31, 2023 Commercial mortgage-backed securities $ 10,673 $ 9,591 Total investment in marketable securities $ 10,673 $ 9,591
Schedule of Properties Contributed of Annualized Cash Rent	For the three months ended March 31, 2024, the following properties contributed more than 5.0% of our annualized cash rent from office properties, including our share of annualized cash rent from joint venture office properties: Property Three months ended March 31, 2024 One Vanderbilt Avenue 16.7% 11 Madison Avenue 8.8% 420 Lexington Ave 7.2% 1515 Broadway 6.7% 1185 Avenue of the Americas 6.0% 245 Park Avenue 5.6% 280 Park Avenue 5.0%

Property Acquisitions and Con_2

Property Acquisitions and Consolidations (Tables)	3 Months Ended
	Mar. 31, 2024
Business Combination and Asset Acquisition [Abstract]
Schedule of Business Acquisitions, by Acquisition	The following table summarizes the properties consolidated during the three months ended March 31, 2024: Property Consolidation Date Property Type Approximate Square Feet Gross Asset Valuation 10 East 53rd Street (1) March 2024 Fee Interest 354,300 $ 236.0 (1) In March 2024, the Company entered into an agreement to acquire its partner's 45.0% interest in the joint venture for cash consideration of $7.2 million, which is net of all outstanding debt obligations at contract signing. As a result of the contract terms, it was concluded that the joint venture is a VIE in which the Company is the primary beneficiary, and the investment was consolidated in our financial statements. Upon consolidating the entity, the assets and liabilities of the entity were recorded at fair value which resulted in the recognition of a fair value adjustment of ($55.7 million), which is included in Purchase price and other fair value adjustments in the consolidated statements of operations. Prior to March 2024, the investment was accounted for under the equity method. See Note 16, "Fair Value Measurements."

Debt and Preferred Equity Inv_2

Debt and Preferred Equity Investments (Tables)	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Activity in Debt and Preferred Equity Investments	Below is a summary of the activity in our debt and preferred equity investments for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of year (1) $ 346,745 $ 623,280 Debt investment originations/fundings/accretion (2) 3,487 72,160 Preferred equity investment originations/accretion (2) 2,115 8,142 Redemptions/sales/syndications/equity ownership/amortization — (349,947) Net change in loan loss reserves — (6,890) Balance at end of period (1) (3) $ 352,347 $ 346,745 (1) Net of unamortized fees, discounts, and premiums. (2) Accretion includes amortization of fees and discounts and paid-in-kind investment income. (3) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio.
Schedule of Debt and Preferred Equity Investments	Below is a summary of our debt and preferred equity investments as of March 31, 2024 (dollars in thousands): Floating Rate Fixed Rate Total Carrying Value Senior Financing Maturity (2) Type Carrying Value Face Value Interest Rate (1) Carrying Value Face Value Interest Rate Mezzanine Debt $ 172,232 $ 172,391 S + 4.95% - 12.38% $ 50,000 $ 50,000 8.00% - 8.40% $ 222,232 (3) $ 1,084,257 2024 - 2029 Preferred Equity — — — 130,115 130,115 6.5% 130,115 250,000 2027 Balance at end of period $ 172,232 $ 172,391 $ 180,115 $ 180,115 $ 352,347 $ 1,334,257 (1) Floating interest rates are presented with the stated spread over Term SOFR ("S"). (2) Excludes available extension options to the extent they have not been exercised as of the date of this filing. (3) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio.
Schedule of Roll Forward of our Total Allowance for Loan Losses	The following table is a roll forward of our total allowance for loan losses for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of year $ 13,520 $ 6,630 Current period provision for loan loss — 6,890 Balance at end of period (1) $ 13,520 $ 13,520 (1) As of March 31, 2024, all debt and preferred equity investments on non-accrual had an allowance for loan loss except for one debt investment with a carrying value of $49.8 million, which is included in the Company's alternative strategy portfolio.
Schedule of Carrying Value of Debt and Preferred Equity Investment Portfolio by Year of Origination and Risk Rating	The following table sets forth the carrying value of our debt and preferred equity investment portfolio by risk rating as of March 31, 2024 and December 31, 2023 (dollars in thousands): Risk Rating March 31, 2024 December 31, 2023 1 - Low Risk Assets - Low probability of loss $ 214,740 $ 210,333 2 - Watch List Assets - Higher potential for loss (1) 137,607 136,412 3 - High Risk Assets - Loss more likely than not — — $ 352,347 $ 346,745 (1) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio. The following table sets forth the carrying value of our debt and preferred equity investment portfolio by year of origination and risk rating as of March 31, 2024 (dollars in thousands): As of March 31, 2024 Risk Rating 2024 (1) 2023 (1) 2022 (1) Prior (1) Total 1 - Low Risk Assets - Low probability of loss $ — $ — $ — $ 214,740 $ 214,740 2 - Watch List Assets - Higher potential for loss — — — 137,607 (2) 137,607 3 - High Risk Assets - Loss more likely than not — — — — — $ — $ — $ — $ 352,347 $ 352,347 (1) Year in which the investment was originated or acquired by us or in which a material modification occurred. (2) Includes two investments with a total carrying value of $49.8 million that are included in the Company's alternative strategy portfolio.
Schedule of Debt Investments with an Aggregate Weighted Average Current Yield	As of March 31, 2024 and December 31, 2023, we held the following debt investments with an aggregate weighted average current yield of 8.72% as of March 31, 2024 (dollars in thousands): Loan Type March 31, 2024 March 31, 2024 Senior March 31, 2024 Carrying Value (1) December 31, 2023 (1) Maturity (2) Fixed Rate Investments: Mezzanine Loan (3) (4) (6) $ — $ 105,000 $ 13,366 $ 13,366 June 2024 Mezzanine Loan — 95,000 30,000 30,000 January 2025 Mezzanine Loan — 85,000 20,000 20,000 December 2029 Total fixed rate $ — $ 285,000 $ 63,366 $ 63,366 Floating Rate Investments: Mezzanine Loan (5) (6) $ — $ 275,000 $ 50,000 $ 50,000 April 2023 Mezzanine Loan 3,761 54,000 8,243 8,243 May 2024 Mezzanine Loan 370 284,173 64,624 62,333 May 2024 Mezzanine Loan 9,565 186,084 49,519 48,323 January 2026 Total floating rate $ 13,696 $ 799,257 $ 172,386 $ 168,899 Allowance for loan loss $ — $ — $ (13,520) $ (13,520) Total $ 13,696 $ 1,084,257 $ 222,232 $ 218,745 (1) Carrying value is net of discounts, premiums, original issue discounts and deferred origination fees. (2) Represents contractual maturity, excluding any extension options to the extent they have not been exercised as of the date of this filing. (3) Carrying value is net of a $12.0 million participation that was sold and did not meet the conditions for sale accounting. That participation is included in Other assets and Other liabilities on the consolidated balance sheets as a result. (4) This loan went into default and was put on non-accrual in June 2020 and remains on non-accrual as of March 31, 2024. No investment income has been recognized subsequent to it being put on non-accrual. In the first quarter of 2023, the Company fully reserved the balance of the investment. Additionally, we determined the borrower entity to be a VIE, in which we are not the primary beneficiary. (5) This loan went into default and was put on non-accrual in January 2023 and remains on non-accrual as of March 31, 2024. No investment income has been recognized subsequent to it being put on non-accrual. The Company is in discussions with the borrower with respect to the loan. (6) Included in the Company's alternative strategy portfolio.
Schedule of Preferred Equity Investments with an Aggregate Weighted Average Current Yield	As of March 31, 2024 and December 31, 2023, we held the following preferred equity investment with an aggregate weighted average current yield of 6.55% as of March 31, 2024 (dollars in thousands): Type March 31, 2024 March 31, 2024 Senior March 31, 2024 Carrying Value (1) December 31, 2023 (1) Mandatory Redemption (2) Preferred Equity $ — $ 250,000 $ 130,115 $ 128,000 February 2027 Allowance for loan loss $ — $ — $ — $ — Total $ — $ 250,000 $ 130,115 $ 128,000 (1) Carrying value is net of deferred origination fees. (2) Represents contractual redemption, excluding any unexercised extension options.

Investments in Unconsolidated_2

Investments in Unconsolidated Joint Ventures (Tables)	3 Months Ended
	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Schedule of General Information on Joint Ventures and Investments in Unconsolidated Joint Ventures Sold	The table below provides general information on each of our joint ventures as of March 31, 2024: Property Partner Ownership (1) Economic (1) Unaudited Approximate Square Feet 100 Park Avenue Prudential Real Estate Investors 49.90% 49.90% 834,000 800 Third Avenue Private Investors 60.52% 60.52% 526,000 919 Third Avenue New York State Teacher's Retirement System 51.00% 51.00% 1,454,000 11 West 34th Street (2) Private Investor / Wharton Properties 30.00% 30.00% 17,150 280 Park Avenue Vornado Realty Trust 50.00% 50.00% 1,219,158 1552-1560 Broadway (2) (3) Wharton Properties 50.00% 50.00% 57,718 650 Fifth Avenue (2) (4) Wharton Properties 50.00% 50.00% 69,214 11 Madison Avenue PGIM Real Estate 60.00% 60.00% 2,314,000 One Vanderbilt Avenue National Pension Service of Korea / Hines Interest LP 71.01% 71.01% 1,657,198 Worldwide Plaza (2) RXR Realty / New York REIT 24.95% 24.95% 2,048,725 1515 Broadway Allianz Real Estate of America 56.87% 56.87% 1,750,000 2 Herald Square (2) (5) Israeli Institutional Investor 95.00% 95.00% 369,000 115 Spring Street (2) Private Investor 51.00% 51.00% 5,218 15 Beekman (6) A fund managed by Meritz Alternative Investment Management 20.00% 20.00% 221,884 85 Fifth Avenue Wells Fargo 36.27% 36.27% 12,946 One Madison Avenue (7) National Pension Service of Korea / Hines Interest LP / International Investor 25.50% 25.50% 1,048,700 220 East 42nd Street A fund managed by Meritz Alternative Investment Management 51.00% 51.00% 1,135,000 450 Park Avenue (8) Korean Institutional Investor / Israeli Institutional Investor 50.10% 25.10% 337,000 5 Times Square (2) RXR Realty led investment group 31.55% 31.55% 1,131,735 245 Park Avenue (9) U.S. Affiliate of Mori Trust Co., Ltd 50.10% 50.10% 1,782,793 625 Madison Avenue (10) Private Investor 90.43% 90.43% 563,000 (1) Ownership interest and economic interest represent the Company's interests in the joint venture as of March 31, 2024. Changes in ownership or economic interests within the current year are disclosed in the notes below. (2) Included in the Company's alternative strategy portfolio. (3) The joint venture owns a long-term leasehold interest in the retail space and certain other spaces at 1560 Broadway, which is adjacent to 1552 Broadway. (4) The joint venture owns a long-term leasehold interest in the retail space at 650 Fifth Avenue. (5) In January 2024, the Company closed on the acquisition of interests in the joint venture that owns the leasehold interest for no consideration, which increases the Company's interest in the joint venture to 95.0%. (6) In 2020, the Company formed a joint venture, which then entered into a long-term sublease with the Company. (7) In 2021, the Company admitted an additional partner to the development project with the partner's indirect ownership in the joint venture totaling 25.0%. The transaction did not meet sale accounting under ASC 860 and, as a result, was treated as a secured borrowing for accounting purposes and is included in Other liabilities in our consolidated balance sheets at March 31, 2024 and December 31, 2023. (8) The 50.1% ownership interest reflected in this table is comprised of our 25.1% economic interest and a 25.0% economic interest held by a third-party. The third-party's economic interest is held within a joint venture that we consolidate and recognize in Noncontrolling interests in other partnerships on our consolidated balance sheet. An additional third-party owns the remaining 49.9% economic interest in the property. (9) In June 2023, the Company sold a 49.9% interest, which resulted in the Company no longer retaining a controlling interest in the entity, as defined in ASC 810, and deconsolidation of the 50.1% interest we retained. We recorded our investment at fair value which resulted in the recognition of a fair value adjustment of ($17.0 million) during the year ended December 31, 2023. The fair value of our investment was determined by the terms of the joint venture agreement. (10) In September 2023, following a UCC foreclosure, the Company converted its previous mezzanine debt investments in the fee interest to a 90.43% ownership interest. In December 2023, together with its joint venture partner, the Company entered into a contract to sell the fee ownership in the property. In connection with this contract, the Company recorded a charge of $23.1 million for the year ended December 31, 2023. As of March 31, 2024, the transaction has not closed and the Company recorded an additional charge of $5.9 million for capital contributions required during the quarter, which is included in Depreciable real estate reserves and impairments in the consolidated statements of operations. This transaction is expected to close in the second quarter of 2024. The following table summarizes the investments in unconsolidated joint ventures sold during the three months ended March 31, 2024: Property Ownership Interest Sold Disposition Date Gross Asset Valuation (in millions) Gain on Sale (in millions) (1) 717 Fifth Avenue 10.92% January 2024 $ 963.0 $ 26.9 (1) Represents the Company's share of the gain.
Schedule of Mortgage Notes and Other Loans Payable Collateralized by the Respective Joint Venture Properties and Assignment of Leases	The mortgage notes and other loans payable collateralized by the respective joint venture properties and assignment of leases as of March 31, 2024 and December 31, 2023, respectively, are as follows (dollars in thousands): Principal Outstanding Principal Outstanding Economic Current Maturity Final Maturity Interest March 31, 2024 December 31, 2023 Property Interest (1) Date Date (2) Rate (3) Gross SLG Share Gross SLG Share Fixed Rate Debt: 220 East 42nd Street 51.00 % June 2024 June 2025 5.86% $ 505,412 $ 257,760 $ 505,412 $ 257,760 650 Fifth Avenue (4) 50.00 % July 2024 July 2024 5.45% 65,000 32,500 65,000 32,500 5 Times Square (4) 31.55 % September 2024 September 2026 7.18% 514,897 162,450 477,783 150,740 1515 Broadway 56.87 % March 2025 March 2025 3.93% 756,777 430,371 762,002 433,344 115 Spring Street (4) 51.00 % March 2025 March 2025 5.50% 65,550 33,431 65,550 33,431 450 Park Avenue 25.10 % June 2025 June 2027 6.10% 273,616 68,678 271,394 68,120 11 Madison Avenue 60.00 % September 2025 September 2025 3.84% 1,400,000 840,000 1,400,000 840,000 One Madison Avenue (5) 25.50 % November 2025 November 2026 3.59% 769,105 196,122 733,103 186,941 15 Beekman 20.00 % January 2026 January 2028 5.99% 120,000 24,000 — — 800 Third Avenue 60.52 % February 2026 February 2026 3.37% 177,000 107,120 177,000 107,120 919 Third Avenue 51.00 % April 2026 April 2028 6.11% 500,000 255,000 500,000 255,000 625 Madison Avenue (6) 90.43 % December 2026 December 2026 5.07% 201,570 182,280 199,987 180,848 245 Park Avenue 50.10 % June 2027 June 2027 4.30% 1,768,000 885,768 1,768,000 885,768 Worldwide Plaza (4) 24.95 % November 2027 November 2027 3.98% 1,200,000 299,400 1,200,000 299,400 One Vanderbilt Avenue 71.01 % July 2031 July 2031 2.95% 3,000,000 2,130,300 3,000,000 2,130,300 10 East 53rd Street — — 220,000 121,000 717 Fifth Avenue — — 655,328 71,536 Total fixed rate debt $ 11,316,927 $ 5,905,180 $ 12,000,559 $ 6,053,808 Floating Rate Debt: 11 West 34th Street (4) 30.00 % February 2023 (7) February 2023 (7) L+ 1.45% $ 23,000 $ 6,900 $ 23,000 $ 6,900 1552 Broadway (4) 50.00 % February 2024 (8) February 2024 (8) S+ 2.75% 193,132 96,566 193,133 96,567 100 Park Avenue 49.90 % May 2024 (9) December 2025 (10) S+ 2.36% 360,000 179,640 360,000 179,640 650 Fifth Avenue (4) 50.00 % July 2024 July 2024 S+ 2.25% 210,000 105,000 210,000 105,000 5 Times Square (4) 31.55 % September 2024 September 2026 S+ 5.61% 615,094 194,062 610,010 192,458 280 Park Avenue (11) 50.00 % September 2024 September 2024 S+ 2.03% 1,200,000 600,000 1,200,000 600,000 2 Herald Square — — 182,500 93,075 15 Beekman — — 124,137 24,827 Total floating rate debt $ 2,601,226 $ 1,182,168 $ 2,902,780 $ 1,298,467 Total joint venture mortgages and other loans payable $ 13,918,153 $ 7,087,348 $ 14,903,339 $ 7,352,275 Deferred financing costs, net (93,904) (50,598) (104,062) (54,865) Total joint venture mortgages and other loans payable, net $ 13,824,249 $ 7,036,750 $ 14,799,277 $ 7,297,410 (1) Economic interest represents the Company's interests in the joint venture as of March 31, 2024. Changes in ownership or economic interests, if any, within the current year are disclosed in the notes to the investment in unconsolidated joint ventures table above. (2) Reflects exercise of all available options. The ability to exercise extension options may be subject to certain conditions, including meeting tests based on the operating performance of the property. (3) Interest rates as of March 31, 2024, taking into account interest rate hedges in effect during the period. Floating rate debt is presented with the stated spread over Term SOFR ("S"). (4) Included in the Company's alternative strategy portfolio. (5) The loan is a $1.25 billion construction facility with an initial term of five years with one, one year extension option. Advances under the loan are subject to costs incurred. In conjunction with the loan, the Company provided partial guarantees for interest and principal payments, the amounts of which are based on certain construction milestones and operating metrics. In July 2023, the facility was modified, which will allow the partnership to utilize the final tranche of the facility for an expanded range of uses, including additional amenities funded by construction cost savings and for hedging activities in contemplation of a permanent financing. (6) Represents $170.5 million of loan principal and $31.1 million of accrued interest. (7) The Company's joint venture partner is in discussions with the lender on resoluteness, given that the loan is past maturity. (8) The Company is in discussions with the lender on resoluteness, given that the loan is past maturity. (9) In April 2024, together with its joint venture partner, the Company exercised an extension option through December 2024. (10) As-of-right extension. (11) In April 2024, together with our joint venture partner, closed on a modification and extension of the $1.075 billion securitized mortgage loan. The modification extended the maturity date to September 2026, with the partnership's option to extend to a fully extended maturity date of September 2028. The interest rate was maintained at 1.78% over Term SOFR, which the Company fixed at 5.91% for its share of the debt through the fully extended maturity date. The partnership separately modified and extended the $125.0 million mezzanine loan and subsequently repaid the loan for $62.5 million.
Schedule of Combined Balance Sheets for the Unconsolidated Joint Ventures	The combined balance sheets for the unconsolidated joint ventures, at March 31, 2024 and December 31, 2023 are as follows (in thousands): March 31, 2024 December 31, 2023 Assets (1) Commercial real estate property, net $ 18,024,642 $ 18,467,340 Cash and restricted cash 608,462 656,038 Tenant and other receivables, related party receivables, and deferred rents receivable 634,813 673,532 Other assets 2,538,878 2,584,765 Total assets $ 21,806,795 $ 22,381,675 Liabilities and equity (1) Mortgages and other loans payable, net $ 13,824,249 $ 14,799,277 Deferred revenue 1,070,740 1,108,180 Lease liabilities 987,299 990,276 Other liabilities 430,533 447,705 Equity 5,493,974 5,036,237 Total liabilities and equity $ 21,806,795 $ 22,381,675 Company's investments in unconsolidated joint ventures $ 2,984,786 $ 2,983,313 (1) At March 31, 2024, $548.2 million of net unamortized basis differences between the amount at which our investments are carried and our share of equity in net assets of the underlying property will be amortized through equity in net income (loss) from unconsolidated joint ventures over the remaining life of the underlying items having given rise to the differences.
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 three months ended March 31, 2024 and 2023, are as follows (in thousands): Three Months Ended March 31, 2024 2023 Total revenues $ 365,339 $ 389,452 Operating expenses 65,750 61,968 Real estate taxes 75,632 65,740 Operating lease rent 9,025 7,181 Interest expense, net of interest income 149,854 129,477 Amortization of deferred financing costs 6,072 7,045 Depreciation and amortization 134,178 125,266 Total expenses 440,511 396,677 Gain on early extinguishment of debt 172,519 — Net income (loss) before loss on sale $ 97,347 $ (7,225) Company's equity in net income (loss) from unconsolidated joint ventures $ 111,160 $ (7,412)

Deferred Costs (Tables)

Deferred Costs (Tables)	3 Months Ended
	Mar. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Components of Deferred Costs	Deferred costs as of March 31, 2024 and December 31, 2023 consisted of the following (in thousands): March 31, 2024 December 31, 2023 Deferred leasing costs $ 402,025 $ 399,224 Less: accumulated amortization (292,729) (287,761) Deferred costs, net $ 109,296 $ 111,463

Mortgages and Other Loans Pay_2

Mortgages and Other Loans Payable (Tables)	3 Months Ended
	Mar. 31, 2024
Mortgages and Other Loans Payable
Schedule of Mortgages and Other Loans Payable	The mortgages and other loans payable collateralized by the respective properties and assignment of leases or debt investments as of March 31, 2024 and December 31, 2023, respectively, were as follows (dollars in thousands): Property Maturity Final Maturity Date (1) Interest Rate (2) March 31, 2024 December 31, 2023 Fixed Rate Debt: 420 Lexington Avenue October 2024 October 2040 3.99% $ 275,737 $ 277,238 10 East 53rd Street May 2025 May 2028 (3) 5.45% 205,000 — 100 Church Street June 2025 June 2027 5.89% 370,000 370,000 7 Dey / 185 Broadway November 2025 November 2026 (3) 6.65% 190,148 190,148 Landmark Square January 2027 January 2027 4.90% 100,000 100,000 485 Lexington Avenue February 2027 February 2027 4.25% 450,000 450,000 Total fixed rate debt $ 1,590,885 $ 1,387,386 Floating Rate Debt: 690 Madison Avenue (4) July 2024 July 2025 S+ 0.50% $ 60,493 $ 60,000 719 Seventh Avenue (4)(5) December 2024 December 2024 S+ 1.31% 50,000 50,000 Total floating rate debt $ 110,493 $ 110,000 Total mortgages and other loans payable $ 1,701,378 $ 1,497,386 Deferred financing costs, net of amortization (6,215) (6,067) Total mortgages and other loans payable, net $ 1,695,163 $ 1,491,319 (1) Reflects exercise of all available options. The ability to exercise extension options may be subject to certain tests based on the operating performance of the property. (2) Interest rate as of March 31, 2024, taking into account interest rate hedges in effect during the period. Floating rate debt is presented with the stated spread over Term SOFR ("S"), unless otherwise specified. (3) As-of-right extension. (4) Included in the Company's alternative strategy portfolio. (5) In April 2024, the Company entered into an agreement to sell 719 Seventh Avenue. In connection with the sale, the Company will repay the existing $50.0 million mortgage for $32.0 million.

Corporate Indebtedness (Tables)

Corporate Indebtedness (Tables)	3 Months Ended
	Mar. 31, 2024
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 March 31, 2024 and December 31, 2023, respectively, by scheduled maturity date (dollars in thousands): Issuance March 31, 2024 March 31, 2024 December 31, Interest Rate (1) Initial Term Maturity Date December 17, 2015 (2) $ 100,000 $ 100,000 $ 100,000 4.27 % 10 December 2025 $ 100,000 $ 100,000 $ 100,000 Deferred financing costs, net — (180) (205) $ 100,000 $ 99,820 $ 99,795 (1) Interest rate as of March 31, 2024. (2) Issued by the Company and the Operating Partnership as co-obligors in a private placement.
Schedule of Combined Aggregate Principal Maturities	Combined aggregate principal maturities of mortgages and other loans payable, the 2021 credit facility, trust preferred securities, senior unsecured notes and our share of joint venture debt as of March 31, 2024, including as-of-right extension options, were as follows (in thousands): Scheduled Principal Revolving Unsecured Term Loans Trust Senior Total Joint Remaining 2024 $ 2,987 $ 383,243 $ — $ 200,000 $ — $ — $ 586,230 $ 1,488,241 2025 — 370,000 — — — 100,000 470,000 1,739,239 2026 — 190,148 — — — — 190,148 544,400 2027 — 550,000 650,000 1,050,000 — — 2,250,000 1,185,168 2028 — 205,000 — — — — 205,000 — Thereafter — — — — 100,000 — 100,000 2,130,300 $ 2,987 $ 1,698,391 $ 650,000 $ 1,250,000 $ 100,000 $ 100,000 $ 3,801,378 $ 7,087,348
Schedule of Consolidated Interest Expense, Excluding Capitalized Interest	Consolidated interest expense, excluding capitalized interest, was comprised of the following (in thousands): Three Months Ended March 31, 2024 2023 Interest expense before capitalized interest $ 48,869 $ 64,843 Interest on financing leases 1,120 1,106 Capitalized interest (17,949) (25,464) Amortization of discount on assumed debt — 1,487 Interest income (867) (319) Interest expense, net $ 31,173 $ 41,653

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
Schedule of Amounts Due from/to Related Parties	Amounts due from joint ventures, inclusive of our ownership share of the joint ventures, and related parties as of March 31, 2024 and December 31, 2023 consisted of the following (in thousands): March 31, 2024 December 31, 2023 Due from joint ventures $ 10,619 $ 10,603 Other 1,610 1,565 Related party receivables $ 12,229 $ 12,168

Noncontrolling Interests on t_2

Noncontrolling Interests on the Company's Consolidated Financial Statements (Tables)	3 Months Ended
	Mar. 31, 2024
Noncontrolling Interest [Abstract]
Schedule of Noncontrolling Interest	Below is a summary of the activity relating to the noncontrolling interests in the Operating Partnership for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of period $ 238,051 $ 269,993 Distributions (3,609) (14,779) Issuance of common units 6,025 25,365 Redemption and conversion of common units (13,596) (18,589) Net income (loss) 901 (37,465) Accumulated other comprehensive income (loss) allocation 1,622 (1,960) Fair value adjustment 42,841 15,486 Balance at end of period $ 272,235 $ 238,051
Schedule of Preferred Unit Activity	Below is a summary of the preferred units of limited partnership interest in the Operating Partnership as of March 31, 2024: Issuance Stated Distribution Rate Number of Units Authorized Number of Units Issued Number of Units Outstanding Annual Dividend Per Unit (1) Liquidation Preference Per Unit (2) Conversion Price Per Unit (3) Date of Issuance Series A (4) 5.00 % 109,161 109,161 109,161 $ 50.0000 $ 1,000.00 $ — August 2015 Series F 7.00 % 60 60 60 70.0000 1,000.00 29.12 January 2007 Series K 3.50 % 700,000 563,954 341,677 0.8750 25.00 134.67 August 2014 Series L 4.00 % 500,000 378,634 372,634 1.0000 25.00 — August 2014 Series R 3.50 % 400,000 400,000 400,000 0.8750 25.00 154.89 August 2015 Series S 4.00 % 1,077,280 1,077,280 1,077,280 1.0000 25.00 — August 2015 Series V (5) 5.00 % 40,000 40,000 40,000 1.2500 25.00 — May 2019 Series W (6) (6) 1 1 1 (6) (6) (6) January 2020 (1) Dividends are cumulative, subject to certain provisions. (2) Units are redeemable at any time at par for cash at the option of the unit holder unless otherwise specified. (3) If applicable, 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) the amount shown in the table. (4) Issued through a consolidated subsidiary. The units are convertible on a one-for-one basis, into the Series B Preferred Units of limited partnership interest, or the Subsidiary Series B Preferred Units. The Subsidiary Series B Preferred Units can be converted at any time, after July 15, 2024 at the option of the unitholder, into a number of common stock equal to 6.71348 shares of common stock for each Subsidiary Series B Preferred Unit. As such, no Subsidiary Series B Preferred Units have been issued as of March 31, 2024 (5) The Series V Preferred Units are redeemable at any time after January 1, 2025 at par for cash at the option of the unit holder. (6) The Series W preferred unit was issued in January 2020 in exchange for the then-outstanding Series O preferred unit. The holder of the Series W preferred unit is entitled to quarterly dividends in an amount calculated as (i) 1,350 multiplied by (ii) the current distribution per common unit of limited partnership in SL Green Operating Partnership. The holder has the right to require the Operating Partnership to repurchase the Series W unit for cash, or convert the Series W unit for Class B units, in each case at a price that is determined based on the closing price of the Company's common stock at the time such right is exercised. The unit's liquidation preference is the fair market value of the unit plus accrued distributions at the time of a liquidation event. Below is a summary of the activity relating to the preferred units in the Operating Partnership for the three months ended March 31, 2024 and the twelve months ended December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Balance at beginning of period $ 166,501 $ 177,943 Issuance of preferred units — — Redemption of preferred units — (11,700) Dividends paid on preferred units (1,920) (6,271) Accrued dividends on preferred units 1,920 6,529 Balance at end of period $ 166,501 $ 166,501

Stockholders' Equity of the C_2

Stockholders' Equity of the Company (Tables)	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Schedule of Class of Treasury Stock	As of March 31, 2024, share repurchases executed under the program, excluding the redemption of OP units, were as follows: Period Shares repurchased Average price paid per share Cumulative number of shares repurchased as part of the repurchase plan or programs Year ended 2023 — $— 36,107,719 Three months ended March 31, 2024 — $— 36,107,719
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 three months ended March 31, 2024 and 2023, respectively (dollars in thousands): Three Months Ended March 31, 2024 2023 Shares of common stock issued 1,662 5,280 Dividend reinvestments/stock purchases under the DRSPP $ 77 $ 184
Schedule of Earnings Per Share	SL Green's earnings per share for the three months ended March 31, 2024 and 2023 are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Income (loss) attributable to SL Green common stockholders $ 13,141 $ (39,731) Less: distributed earnings allocated to participating securities (434) (406) Net income (loss) attributable to SL Green common stockholders (numerator for basic earnings per share) $ 12,707 $ (40,137) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Add back: effect of dilutive securities (redemption of units to common shares) 901 (2,837) Net income (loss) attributable to SL Green common stockholders (numerator for diluted earnings per share) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic Shares: Weighted average common stock outstanding 64,328 64,079 Effect of Dilutive Securities: Operating Partnership units redeemable for common shares 4,439 4,103 Stock-based compensation plans 1,328 — Diluted weighted average common stock outstanding 70,095 68,182

Partners' Capital of the Oper_2

Partners' Capital of the Operating Partnership (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Unit	The Operating Partnership's earnings per unit for the three months ended March 31, 2024 and 2023, respectively, are computed as follows (in thousands): Three Months Ended March 31, Numerator 2024 2023 Basic Earnings: Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,068) Less: distributed earnings allocated to participating securities (434) (906) Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit) $ 13,608 $ (42,974) Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares 434 — Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit) $ 14,042 $ (42,974) Three Months Ended March 31, Denominator 2024 2023 Basic units: Weighted average common units outstanding 68,767 68,182 Effect of Dilutive Securities: Stock-based compensation plans 1,328 — Diluted weighted average common units outstanding 70,095 68,182

Share-based Compensation (Table

Share-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of the Status of Stock Options and Changes During the Period	A summary of the status of the Company's stock options as of March 31, 2024 and December 31, 2023, and changes during the three months ended March 31, 2024 and year ended December 31, 2023 are as follows: March 31, 2024 December 31, 2023 Options Outstanding Weighted Average Options Outstanding Weighted Average Balance at beginning of period 115,980 $ 103.52 313,480 $ 97.59 Exercised — — — — Lapsed or canceled — — (197,500) 84.14 Balance at end of period 115,980 $ 103.52 115,980 $ 103.52 Options exercisable at end of period 115,980 $ 103.52 115,980 $ 103.52
Schedule of Other Share-based Compensation, Activity	A summary of the Company's restricted stock as of March 31, 2024 and December 31, 2023 and changes during the three months ended March 31, 2024 and the year ended December 31, 2023, are as follows: March 31, 2024 December 31, 2023 Balance at beginning of period 4,089,174 3,758,174 Granted 3,234 337,350 Canceled (7,450) (6,350) Balance at end of period 4,084,958 4,089,174 Vested during the period 134,620 147,915 Compensation expense recorded $ 2,625,319 $ 7,766,055 Total fair value of restricted stock granted during the period $ 151,901 $ 15,789,540

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The following tables set forth the changes in accumulated other comprehensive income by component as of March 31, 2024 (in thousands): Net unrealized gain (loss) on derivative instruments ( 1 ) SL Green’s share of joint venture net unrealized (loss) gain on derivative instruments ( 2 ) Net unrealized (loss) gain on marketable securities Total Balance at December 31, 2023 $ 25,352 $ (6,084) $ (1,791) $ 17,477 Other comprehensive income before reclassifications 29,023 5,409 1,019 35,451 Amounts reclassified from accumulated other comprehensive income (9,095) (3,682) — (12,777) Balance at March 31, 2024 $ 45,280 $ (4,357) $ (772) $ 40,151 (1) Amount reclassified from accumulated other comprehensive income is included in interest expense in the respective consolidated statements of operations. As of March 31, 2024 and December 31, 2023, the deferred net gains from these terminated hedges, which is included in accumulated other comprehensive income relating to net unrealized gain (loss) on derivative instruments, was ($0.3 million) and ($0.4 million), respectively. (2) Amount reclassified from accumulated other comprehensive income is included in equity in net income (loss) from unconsolidated joint ventures in the respective consolidated statements of operations.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of 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 as of March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 Total Level 1 Level 2 Level 3 Assets: Marketable securities available-for-sale $ 10,673 $ — $ 10,673 $ — Interest rate cap and swap agreements (included in Other assets) 51,388 — 51,388 — Liabilities: Interest rate cap and swap agreements (included in Other liabilities) $ 7,754 $ — $ 7,754 $ — December 31, 2023 Total Level 1 Level 2 Level 3 Assets: Marketable securities available-for-sale $ 9,591 $ — $ 9,591 $ — Interest rate cap and swap agreements (included in Other assets) 33,456 — 33,456 — Liabilities: Interest rate cap and swap agreements (included in Other liabilities) $ 17,108 $ — $ 17,108 $ —
Schedule of Fair Value, by Balance Sheet Grouping	The following table provides the carrying value and fair value of these financial instruments as of March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 December 31, 2023 Carrying Value (1) Fair Value Carrying Value (1) Fair Value Debt and preferred equity investments $ 352,347 (2) $ 346,745 (2) Fixed rate debt $ 3,040,885 $ 2,973,363 $ 3,237,386 $ 3,184,338 Variable rate debt (3) 760,493 759,604 270,000 268,787 $ 3,801,378 $ 3,732,967 $ 3,507,386 $ 3,453,125 (1) Amounts exclude net deferred financing costs. (2) As of March 31, 2024, debt and preferred equity investments had an estimated fair value of approximately $0.3 billion. As of December 31, 2023, debt and preferred equity investments had an estimated fair value of approximately $0.3 billion. (3)

Financial Instruments_ Deriva_2

Financial Instruments: Derivatives and Hedging (Tables)	3 Months Ended
	Mar. 31, 2024
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 as of March 31, 2024 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 (dollars in thousands). Notional Strike Effective Expiration Balance Sheet Location Fair Interest Rate Cap 370,000 3.250 % June 2023 June 2024 Other Assets $ 1,565 Interest Rate Cap 370,000 3.250 % June 2023 June 2024 Other Liabilities (1,562) Interest Rate Cap 220,000 4.000 % February 2024 February 2025 Other Assets 1,789 Interest Rate Swap 150,000 2.621 % December 2021 January 2026 Other Assets 4,915 Interest Rate Swap 200,000 2.662 % December 2021 January 2026 Other Assets 6,417 Interest Rate Swap 100,000 2.903 % February 2023 February 2027 Other Assets 3,528 Interest Rate Swap 100,000 2.733 % February 2023 February 2027 Other Assets 3,983 Interest Rate Swap 50,000 2.463 % February 2023 February 2027 Other Assets 2,354 Interest Rate Swap 200,000 2.591 % February 2023 February 2027 Other Assets 8,730 Interest Rate Swap 300,000 2.866 % July 2023 May 2027 Other Assets 11,314 Interest Rate Swap 150,000 3.524 % January 2024 May 2027 Other Assets 2,794 Interest Rate Swap 370,000 3.888 % November 2022 June 2027 Other Assets 2,879 Interest Rate Swap (1) 300,000 4.487 % November 2024 November 2027 Other Liabilities (5,113) Interest Rate Swap 100,000 3.756 % January 2023 January 2028 Other Assets 1,120 Interest Rate Swap 204,963 3.915 % February 2025 May 2028 Other Liabilities (1,079) $ 43,634 (1) Quarterly changes in fair value recognized in the calculation of FFO. The following table summarizes the notional value at inception and fair value of our joint ventures' derivative financial instruments as of March 31, 2024 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 (dollars in thousands). Notional Strike Effective Expiration Classification Fair Interest Rate Cap $ 501,650 0.490 % February 2022 May 2024 Asset $ 2,560 Interest Rate Cap 501,650 0.490 % February 2022 May 2024 Asset 2,560 Interest Rate Cap 505,412 3.000 % June 2023 June 2024 Asset 2,490 Interest Rate Cap 273,616 4.000 % August 2023 August 2024 Asset 1,212 Interest Rate Cap 514,897 3.500 % September 2023 September 2024 Asset 4,118 Interest Rate Cap 278,161 4.000 % May 2024 November 2024 Asset 1,624 Interest Rate Cap 278,161 4.000 % May 2024 November 2024 Asset 1,624 Interest Rate Swap 250,000 3.608 % April 2023 February 2026 Asset 4,070 Interest Rate Swap 250,000 3.608 % April 2023 February 2026 Asset 4,069 Interest Rate Swap 177,000 1.555 % December 2022 February 2026 Asset 9,459 $ 33,786
Schedule of Effect of Derivative Financial Instruments on Consolidated Statements of Income	The following table presents the effect of our derivative financial instruments and our share of our joint ventures' derivative financial instruments that are designated and qualify as hedging instruments on the consolidated statements of operations for the three months ended March 31, 2024 and 2023, respectively (in thousands): Amount of Gain Recognized in Location of Gain Reclassified from Accumulated Other Comprehensive Income into Income Amount of Gain Reclassified from Three Months Ended March 31, Three Months Ended March 31, Derivative 2024 2023 2024 2023 Interest Rate Swaps/Caps $ 31,156 $ (17,913) Interest expense $ 9,763 $ 9,023 Share of unconsolidated joint ventures' derivative instruments 5,705 (1,495) Equity in net loss from unconsolidated joint ventures 3,884 2,628 $ 36,861 $ (19,408) $ 13,647 $ 11,651

Lease Income (Tables)

Lease Income (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Schedule of Operating Lease, Lease Income	The components of lease income from operating leases during the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three Months Ended March 31, 2024 2023 Fixed lease payments $ 128,252 $ 166,353 Variable lease payments 13,301 20,450 Total lease payments (1) $ 141,553 $ 186,803 Amortization of acquired above and below-market leases (49) 8,239 Total rental revenue $ 141,504 $ 195,042 (1) Amounts include $48.4 million and $48.9 million of sublease income during the three months ended March 31, 2024 and 2023, respectively.
Schedule of Sales-type Lease, Lease Income	The components of lease income from sales-type leases during the three months ended March 31, 2024 and 2023 were as follows (in thousands): Three Months Ended March 31, 2024 2023 Interest income (1) $ 1,120 $ 1,106 (1) These amounts are included in Other income in our consolidated statements of operations.

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Schedule of Selected Results of Operations and Selected Asset Information	Selected consolidated results of operations for the three months ended March 31, 2024 and 2023, and selected asset information as of March 31, 2024 and December 31, 2023, regarding our operating segments are as follows (in thousands): Real Estate Segment SUMMIT Segment Debt and Preferred Equity Segment Total Company Total revenues Three months ended: March 31, 2024 $ 154,875 $ 25,604 $ 7,403 $ 187,882 March 31, 2023 $ 216,936 $ 19,771 $ 9,057 $ 245,764 Net income (loss) Three months ended: March 31, 2024 $ 12,727 $ 4,453 $ 1,209 $ 18,389 March 31, 2023 $ (42,883) $ (2,418) $ 6,944 $ (38,357) Total assets As of: March 31, 2024 $ 8,946,952 $ 465,787 $ 351,553 $ 9,764,292 December 31, 2023 $ 8,716,738 $ 464,799 $ 349,644 $ 9,531,181

Organization and Basis of Pre_3

Organization and Basis of Presentation - Additional Information (Details) ft² in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) ft² building shares	Dec. 31, 2023
Organization
Debt and preferred equity investments including investments held by unconsolidated joint ventures | $	$ 352.3
Debt and preferred equity investments and other financing receivables included in other balance sheet items | $	$ 4.8
Number of shares to be received on redemption of one unit of limited partnership interests (shares) | shares	1
Managed Office Properties
Organization
Number of buildings | building	1
Approximate Square Feet | ft²	0.4
Retail Site
Organization
Number of buildings | building	1
Service Corporation
Organization
Percentage of ownership in SL Green Management LLC owned by operating partnership (percent)	95%
Operating Partnership | SL Green Operating Partnership
Organization
Noncontrolling interest in the operating partnership (as a percent)	6.38%	5.75%
SL Green Management | SL Green Management LLC
Organization
Percentage of ownership in SL Green Management LLC owned by operating partnership (percent)	100%

Organization and Basis of Pre_4

Organization and Basis of Presentation - Schedule of Commercial Office Properties (Details)	Mar. 31, 2024 ft² building
Commercial properties
Real estate properties
Number of Buildings | building	37
Approximate Square Feet unaudited (sqft)	25,501,181
Weighted Average Leased Occupancy	88%
Core portfolio
Real estate properties
Number of Buildings | building	39
Approximate Square Feet unaudited (sqft)	25,863,447
Consolidated | Commercial properties
Real estate properties
Number of Buildings | building	24
Approximate Square Feet unaudited (sqft)	10,519,660
Consolidated | Core portfolio
Real estate properties
Number of Buildings | building	25
Approximate Square Feet unaudited (sqft)	10,660,042
Unconsolidated | Commercial properties
Real estate properties
Number of Buildings | building	13
Approximate Square Feet unaudited (sqft)	14,981,521
Unconsolidated | Core portfolio
Real estate properties
Number of Buildings | building	14
Approximate Square Feet unaudited (sqft)	15,203,405
Manhattan
Real estate properties
Number of Buildings | building	30
Approximate Square Feet unaudited (sqft)	24,638,381
Weighted Average Leased Occupancy	88.60%
Manhattan | Office
Real estate properties
Number of Buildings | building	24
Approximate Square Feet unaudited (sqft)	21,762,590
Weighted Average Leased Occupancy	88.60%
Manhattan | Retail
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	35,594
Weighted Average Leased Occupancy	100%
Manhattan | Development/Redevelopment
Real estate properties
Number of Buildings | building	4
Approximate Square Feet unaudited (sqft)	2,840,197
Manhattan | Residential
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	362,266
Weighted Average Leased Occupancy	99.60%
Manhattan | Core portfolio
Real estate properties
Weighted Average Leased Occupancy	88.20%
Manhattan | Alternative Strategy Portfolio
Real estate properties
Number of Buildings | building	10
Approximate Square Feet unaudited (sqft)	3,712,844
Weighted Average Leased Occupancy	66.10%
Manhattan | Consolidated
Real estate properties
Number of Buildings | building	17
Approximate Square Feet unaudited (sqft)	9,656,860
Manhattan | Consolidated | Office
Real estate properties
Number of Buildings | building	14
Approximate Square Feet unaudited (sqft)	8,753,441
Manhattan | Consolidated | Retail
Real estate properties
Number of Buildings | building	1
Approximate Square Feet unaudited (sqft)	22,648
Manhattan | Consolidated | Retail | 7 Dey / 185 Broadway
Real estate properties
Approximate Square Feet unaudited (sqft)	140,382
Manhattan | Consolidated | Development/Redevelopment
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	880,771
Manhattan | Consolidated | Residential
Real estate properties
Number of Buildings | building	1
Approximate Square Feet unaudited (sqft)	140,382
Manhattan | Consolidated | Residential | 7 Dey / 185 Broadway
Real estate properties
Approximate Square Feet unaudited (sqft)	50,206
Manhattan | Consolidated | Alternative Strategy Portfolio
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	17,888
Manhattan | Unconsolidated
Real estate properties
Number of Buildings | building	13
Approximate Square Feet unaudited (sqft)	14,981,521
Manhattan | Unconsolidated | Office
Real estate properties
Number of Buildings | building	10
Approximate Square Feet unaudited (sqft)	13,009,149
Manhattan | Unconsolidated | Retail
Real estate properties
Number of Buildings | building	1
Approximate Square Feet unaudited (sqft)	12,946
Manhattan | Unconsolidated | Development/Redevelopment
Real estate properties
Number of Buildings | building	2
Approximate Square Feet unaudited (sqft)	1,959,426
Manhattan | Unconsolidated | Residential
Real estate properties
Number of Buildings | building	1
Approximate Square Feet unaudited (sqft)	221,884
Manhattan | Unconsolidated | Alternative Strategy Portfolio
Real estate properties
Number of Buildings | building	8
Approximate Square Feet unaudited (sqft)	3,694,956
Suburban | Office
Real estate properties
Number of Buildings | building	7
Approximate Square Feet unaudited (sqft)	862,800
Weighted Average Leased Occupancy	73.80%
Suburban | Consolidated | Office
Real estate properties
Number of Buildings | building	7
Approximate Square Feet unaudited (sqft)	862,800
Suburban | Unconsolidated | Office
Real estate properties
Number of Buildings | building	0
Approximate Square Feet unaudited (sqft)	0

Significant Accounting Polici_4

Significant Accounting Policies - Investment in Commercial Real Estate Properties (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2024	Mar. 31, 2024	Mar. 31, 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Rental revenue decrease from amortization of acquired leases		$ 0.1	$ 8.2
719 Seventh Avenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Write down of value in leasehold interest		$ 46.3
719 Seventh Avenue | Subsequent Event | Mathias | Related party
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Proceeds from sale of property	$ 30.5
Minimum | Below-Market Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life of other intangible assets (in years)		1 year
Minimum | Above-Market Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life of other intangible assets (in years)		1 year
Minimum | In-Place Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life of other intangible assets (in years)		1 year
Minimum | Building
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)		3 years
Maximum | Below-Market Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life of other intangible assets (in years)		15 years
Maximum | Above-Market Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life of other intangible assets (in years)		15 years
Maximum | In-Place Leases
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life of other intangible assets (in years)		15 years
Maximum | Building
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)		40 years

Significant Accounting Polici_5

Significant Accounting Policies - Schedule of Identified Intangible Assets and Intangible Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Identified intangible assets (included in other assets):
Gross amount	$ 273,010	$ 189,680
Accumulated amortization	(185,470)	(184,902)
Net	87,540	4,778
Identified intangible liabilities (included in deferred revenue):
Gross amount	226,034	205,394
Accumulated amortization	(202,178)	(202,089)
Net	$ 23,856	$ 3,305

Significant Accounting Polici_6

Significant Accounting Policies - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Investment in Marketable Securities
Marketable securities available-for-sale	$ 10,673	$ 9,591
Total investment in marketable securities	10,673	9,591
Commercial mortgage-backed securities
Investment in Marketable Securities
Marketable securities available-for-sale	$ 10,673	$ 9,591

Significant Accounting Polici_7

Significant Accounting Policies - Investment in Marketable Securities (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($) security	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Real Estate [Line Items]
Proceeds from sale of marketable securities	$ 0	$ 0
Equity marketable securities	0		$ 0
Commercial mortgage-backed securities
Real Estate [Line Items]
Cost basis of commercial mortgage backed securities	$ 11,500,000		11,500,000
Number of securities in unrealized gain position | security	1
Unrealized gain	$ 100,000
Fair market value	5,400,000
Unrealized loss	900,000		1,900,000
Fair value of security in a continuous unrealized loss position for less than 12 months	$ 5,300,000		$ 9,600,000
Debt securities, available-for-sale, continuous unrealized loss position, less than 12 months, number of positions | security	1

Significant Accounting Polici_8

Significant Accounting Policies - Revenue Recognition (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Deferred Revenue Arrangement By Type Table [Line Items]
Days past due for income recognition on debt and preferred equity investments to be suspended	90 days
Deferred revenue	$ 157,756	$ 134,053
Unused and Unexpired Tickets
Deferred Revenue Arrangement By Type Table [Line Items]
Deferred revenue	$ 4,200		$ 3,200

Significant Accounting Polici_9

Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income taxes
Federal, state and local tax provision	$ 700	$ 800
SUMMIT Operator tax (benefit) expense	$ (1,295)	$ 1,267

Significant Accounting Polic_10

Significant Accounting Policies - Schedule of Properties Contributed of Annualized Cash Rent (Details) - Annualized Rent	3 Months Ended
	Mar. 31, 2024 tenant
Customer Concentration
Concentration of Credit Risk
Number of tenants (tenants)	1
Maximum percentage of annualized rent for any one tenant not individually disclosed (percent) (more than)	5%
Investment Property Concentration Risk | One Vanderbilt Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	16.70%
Investment Property Concentration Risk | 11 Madison Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	8.80%
Investment Property Concentration Risk | 420 Lexington Ave
Concentration of Credit Risk
Percentage of concentration (percent)	7.20%
Investment Property Concentration Risk | 1515 Broadway
Concentration of Credit Risk
Percentage of concentration (percent)	6.70%
Investment Property Concentration Risk | 1185 Avenue of the Americas
Concentration of Credit Risk
Percentage of concentration (percent)	6%
Investment Property Concentration Risk | 245 Park Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	5.60%
Investment Property Concentration Risk | 280 Park Avenue
Concentration of Credit Risk
Percentage of concentration (percent)	5%
Tenant 1 | Customer Concentration
Concentration of Credit Risk
Percentage of concentration (percent)	5.50%

Property Acquisitions and Con_3

Property Acquisitions and Consolidations (Details) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) ft²	Mar. 31, 2024 USD ($) ft² property	Dec. 31, 2023 USD ($)
Real Estate [Line Items]
Number of real estate properties acquired from third party | property		0
Investment fair value adjustment			$ 17,000
Investments in unconsolidated joint ventures	$ 2,984,786	$ 2,984,786	$ 2,983,313
10 East 53rd Street
Real Estate [Line Items]
Acquire its partner's interest	45%	45%
Investment fair value adjustment	$ 55,700
Investments in unconsolidated joint ventures	$ 7,200	$ 7,200
10 East 53rd Street
Real Estate [Line Items]
Approximate Square Feet | ft²	354,300	354,300
Gross Asset Valuation (in millions)	$ 236,000	$ 236,000

Properties Held for Sale and _2

Properties Held for Sale and Property Dispositions (Details) $ in Millions	Mar. 31, 2024 USD ($)
Palisades Premier Conference Center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total consideration	$ 26.3

Debt and Preferred Equity Inv_3

Debt and Preferred Equity Investments - Schedule of Activity in Debt and Preferred Equity Investments (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) investment	Dec. 31, 2023 USD ($) investment
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of period	$ 346,745	$ 623,280
Redemptions/sales/syndications/equity ownership/amortization	0	(349,947)
Net change in loan loss reserves	0	(6,890)
Balance at end of period	$ 352,347	$ 346,745
Number of investments, nonperforming | investment	2	2
Carrying Value	$ 352,347	$ 346,745
Total floating rate
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Carrying Value	172,386	168,899
Alternative Strategy Portfolio | Total floating rate
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Carrying Value	49,800
Debt Investment
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Originations/Accretion	3,487	72,160
Preferred Equity Investments
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Originations/Accretion	$ 2,115	$ 8,142

Debt and Preferred Equity Inv_4

Debt and Preferred Equity Investments - Schedule of Debt and Preferred Equity Investments (Details) $ in Thousands	Mar. 31, 2024 USD ($) investment	Dec. 31, 2023 USD ($) investment
Debt Instrument [Line Items]
Carrying Value	$ 352,347	$ 346,745
Senior Financing	$ 1,334,257
Number of investments, nonperforming | investment	2	2
Total floating rate
Debt Instrument [Line Items]
Carrying Value	$ 172,232
Face Value	172,391
Total fixed rate
Debt Instrument [Line Items]
Carrying Value	180,115
Face Value	180,115
Mezzanine Debt
Debt Instrument [Line Items]
Carrying Value	222,232
Senior Financing	1,084,257
Mezzanine Debt | Total floating rate
Debt Instrument [Line Items]
Carrying Value	172,232
Face Value	172,391
Mezzanine Debt | Total fixed rate
Debt Instrument [Line Items]
Carrying Value	50,000
Face Value	50,000
Preferred Equity
Debt Instrument [Line Items]
Carrying Value	130,115
Senior Financing	250,000
Preferred Equity | Total floating rate
Debt Instrument [Line Items]
Carrying Value	0
Face Value	$ 0
Basis spread on variable rate	0%
Preferred Equity | Total fixed rate
Debt Instrument [Line Items]
Carrying Value	$ 130,115
Face Value	$ 130,115
Interest Rate	6.50%
Minimum | Mezzanine Debt | Total fixed rate
Debt Instrument [Line Items]
Interest Rate	8%
Maximum | Mezzanine Debt | Total fixed rate
Debt Instrument [Line Items]
Interest Rate	8.40%
SOFR | Minimum | Mezzanine Debt | Total floating rate
Debt Instrument [Line Items]
Basis spread on variable rate	4.95%
SOFR | Maximum | Mezzanine Debt | Total floating rate
Debt Instrument [Line Items]
Basis spread on variable rate	12.38%

Debt and Preferred Equity Inv_5

Debt and Preferred Equity Investments - Schedule of Roll Forward of our Total Allowance for Loan Losses (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($) loan	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Loan loss reserve activity
Balance at beginning of year	$ 13,520	$ 6,630	$ 6,630
Current period provision for loan loss	0	$ 6,890	6,890
Balance at end of period	$ 13,520		$ 13,520
Number of financing receivables on non-accrual without allowance for loan loss | loan	1
Alternative Strategy Portfolio | Total floating rate
Loan loss reserve activity
Financing receivable on non-accrual without allowance	$ 49,800

Debt and Preferred Equity Inv_6

Debt and Preferred Equity Investments - Narrative (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($) segment investment	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) investment segment
Preferred equity investment
Number of investments, nonperforming | investment	2		2
Debt and preferred equity investments	$ 352,347,000		$ 346,745,000
Recorded investment, past due	$ 352,347,000		$ 346,745,000
Number of portfolio segments of financial receivables (segment) | segment	1		1
Current period provision for loan loss	$ 0	$ 6,890,000	$ 6,890,000
Other Assets
Preferred equity investment
Additional amount of financing receivables included in other assets	5,800,000		8,800,000
Current period provision for loan loss	0	$ 0
Financing Receivables, Equal to Greater than 90 Days Past Due
Preferred equity investment
Recorded investment, past due	0		0
Three Mortgage Investments
Preferred equity investment
Debt and preferred equity investments	49,800,000
Floating Rate
Preferred equity investment
Debt and preferred equity investments	$ 172,386,000		168,899,000
Floating Rate | Mortgage Investment One
Preferred equity investment
Debt and preferred equity investments			$ 49,800,000

Debt and Preferred Equity Inv_7

Debt and Preferred Equity Investments - Schedule of Carrying Value of Debt and Preferred Equity Investment Portfolio by Year of Origination and Risk Rating (Details) $ in Thousands	Mar. 31, 2024 USD ($) investment	Dec. 31, 2023 USD ($) investment
Financing Receivable, Credit Quality Indicator [Line Items]
2024	$ 0
2023	0
2022	0
Prior	352,347
Carrying value	$ 352,347	$ 346,745
Number of investments, nonperforming | investment	2	2
Carrying Value	$ 352,347	$ 346,745
Total floating rate
Financing Receivable, Credit Quality Indicator [Line Items]
Carrying Value	172,386	168,899
Alternative Strategy Portfolio | Total floating rate
Financing Receivable, Credit Quality Indicator [Line Items]
Carrying Value	49,800
1 - Low Risk Assets - Low probability of loss
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	0
Prior	214,740
Carrying value	214,740	210,333
2 - Watch List Assets - Higher potential for loss
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	0
Prior	137,607
Carrying value	137,607	136,412
3 - High Risk Assets - Loss more likely than not
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	0
Prior	0
Carrying value	$ 0	$ 0

Debt and Preferred Equity Inv_8

Debt and Preferred Equity Investments - Schedule of Debt Investments with an Aggregate Weighted Average Current Yield (Details) - USD ($)	3 Months Ended	14 Months Ended	45 Months Ended
	Mar. 31, 2024	Mar. 31, 2024	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate, interest rate	8.72%
Debt Investments Held [Abstract]
Carrying Value, Fixed Rate	$ 352,347,000	$ 352,347,000	$ 352,347,000	$ 346,745,000
Carrying Value	352,347,000	352,347,000	352,347,000	346,745,000
Allowance for loan loss	(13,520,000)	(13,520,000)	(13,520,000)	(13,520,000)	$ (6,630,000)
Mezzanine Loan Due June 2024
Debt Investments Held [Abstract]
Amount participated out	12,000,000	12,000,000	12,000,000
Loan interest income			0
Debt Investments in Mortgage Loans
Debt Investments Held [Abstract]
Future Funding Obligations	13,696,000	13,696,000	13,696,000
Senior Financing	1,084,257,000	1,084,257,000	1,084,257,000
Carrying Value	222,232,000	222,232,000	222,232,000	218,745,000
Allowance for loan loss	(13,520,000)	(13,520,000)	(13,520,000)	(13,520,000)
Total fixed rate
Debt Investments Held [Abstract]
Future Funding Obligations	0	0	0
Senior Financing	285,000,000	285,000,000	285,000,000
Carrying Value, Fixed Rate	63,366,000	63,366,000	63,366,000	63,366,000
Total fixed rate | Mezzanine Loan Due June 2024
Debt Investments Held [Abstract]
Future Funding Obligations	0	0	0
Senior Financing	105,000,000	105,000,000	105,000,000
Carrying Value, Fixed Rate	13,366,000	13,366,000	13,366,000	13,366,000
Total fixed rate | Mezzanine Loan, with an Initial Maturity Date of January 2025
Debt Investments Held [Abstract]
Future Funding Obligations	0	0	0
Senior Financing	95,000,000	95,000,000	95,000,000
Carrying Value, Fixed Rate	30,000,000	30,000,000	30,000,000	30,000,000
Total fixed rate | Mezzanine Loan With Initial Maturity Date of December 2029
Debt Investments Held [Abstract]
Future Funding Obligations	0	0	0
Senior Financing	85,000,000	85,000,000	85,000,000
Carrying Value, Fixed Rate	20,000,000	20,000,000	20,000,000	20,000,000
Total floating rate
Debt Investments Held [Abstract]
Future Funding Obligations	13,696,000	13,696,000	13,696,000
Senior Financing	799,257,000	799,257,000	799,257,000
Carrying Value	172,386,000	172,386,000	172,386,000	168,899,000
Total floating rate | Mezzanine Loan Due April 2023
Debt Investments Held [Abstract]
Future Funding Obligations	0	0	0
Senior Financing	275,000,000	275,000,000	275,000,000
Carrying Value	50,000,000	50,000,000	50,000,000	50,000,000
Loan interest income		0
Total floating rate | Mezzanine Loan Due May 2024
Debt Investments Held [Abstract]
Future Funding Obligations	3,761,000	3,761,000	3,761,000
Senior Financing	54,000,000	54,000,000	54,000,000
Carrying Value	8,243,000	8,243,000	8,243,000	8,243,000
Total floating rate | Mezzanine Loan Due May 2024 One
Debt Investments Held [Abstract]
Future Funding Obligations	370,000	370,000	370,000
Senior Financing	284,173,000	284,173,000	284,173,000
Carrying Value	64,624,000	64,624,000	64,624,000	62,333,000
Total floating rate | Mezzanine Loan Due January 2026
Debt Investments Held [Abstract]
Future Funding Obligations	9,565,000	9,565,000	9,565,000
Senior Financing	186,084,000	186,084,000	186,084,000
Carrying Value	$ 49,519,000	$ 49,519,000	$ 49,519,000	$ 48,323,000

Debt and Preferred Equity Inv_9

Debt and Preferred Equity Investments - Schedule of Preferred Equity Investments with an Aggregate Weighted Average Current Yield (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Preferred equity investment
Mortgage loans on real estate, interest rate	8.72%
Carrying Value	$ 352,347	$ 346,745
Allowance for loan loss	$ (13,520)	(13,520)	$ (6,630)
Preferred Equity
Preferred equity investment
Aggregate weighted average current yield	6.55%
Carrying Value	$ 130,115
Preferred Equity Investments
Preferred equity investment
Mortgage loans on real estate, interest rate	6.55%
Future Funding Obligations	$ 0
Senior Financing	250,000
Allowance for loan loss	0	0
Total after allowance for loan loss	130,115	128,000
Preferred Equity, February 2027
Preferred equity investment
Future Funding Obligations	0
Senior Financing	250,000
Carrying Value	$ 130,115	$ 128,000

Investments in Unconsolidated_3

Investments in Unconsolidated Joint Ventures - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures	$ 2,984,786		$ 2,983,313
Net equity investment in VIEs in which the entity is not primary beneficiary	407,500		$ 437,900
Total revenues	187,882	$ 245,764
Joint venture
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures	2,984,786
Equity method investments with negative book value	144,600
Total revenues	365,339	389,452
Joint venture | Base management service
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 4,900	$ 4,900

Investments in Unconsolidated_4

Investments in Unconsolidated Joint Ventures - Schedule of General Information on Joint Ventures (Details)	1 Months Ended		3 Months Ended		12 Months Ended
	Jan. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Mar. 31, 2024 USD ($) ft²	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2023	Dec. 31, 2021
General information on each joint venture
Depreciable real estate reserves and impairment | $			$ (52,118,000)	$ 0
Mortgages and other loans payable, net | $			1,695,163,000		$ 1,491,319,000
Ownership percentage deconsolidated						50.10%
Investment fair value adjustment | $					17,000,000
245 Park Avenue
General information on each joint venture
Ownership interest disposed						49.90%
625 Madison Avenue
General information on each joint venture
Depreciable real estate reserves and impairment | $		$ 23,100,000	5,900,000
Joint venture
General information on each joint venture
Mortgages and other loans payable, net | $			$ 13,824,249,000		$ 14,799,277,000
Joint venture | 2 Herald Square
General information on each joint venture
Consideration transferred | $	$ 0
Investment in joint venture, ownership percentage	95%
Prudential Real Estate Investors | Joint venture | 100 Park Avenue
General information on each joint venture
Ownership Interest			49.90%
Economic Interest (as a percent)			49.90%
Approximate Square Feet unaudited (sqft)			834,000
Private Investors | Joint venture | 800 Third Avenue
General information on each joint venture
Ownership Interest			60.52%
Economic Interest (as a percent)			60.52%
Approximate Square Feet unaudited (sqft)			526,000
Private Investors | Joint venture | 115 Spring Street
General information on each joint venture
Ownership Interest			51%
Economic Interest (as a percent)			51%
Approximate Square Feet unaudited (sqft)			5,218
New York State Teacher's Retirement System | Joint venture | 919 Third Avenue
General information on each joint venture
Ownership Interest			51%
Economic Interest (as a percent)			51%
Approximate Square Feet unaudited (sqft)			1,454,000
Private Investor / Wharton Properties | Joint venture | 11 West 34th Street
General information on each joint venture
Ownership Interest			30%
Economic Interest (as a percent)			30%
Approximate Square Feet unaudited (sqft)			17,150
Vornado Realty Trust | Joint venture | 280 Park Avenue
General information on each joint venture
Ownership Interest			50%
Economic Interest (as a percent)			50%
Approximate Square Feet unaudited (sqft)			1,219,158
Wharton Properties | Joint venture | 1552-1560 Broadway
General information on each joint venture
Ownership Interest			50%
Approximate Square Feet unaudited (sqft)			57,718
Wharton Properties | Joint venture | 650 Fifth Avenue
General information on each joint venture
Ownership Interest			50%
Economic Interest (as a percent)			50%
Approximate Square Feet unaudited (sqft)			69,214
PGIM Real Estate | Joint venture | 11 Madison Avenue
General information on each joint venture
Ownership Interest			60%
Economic Interest (as a percent)			60%
Approximate Square Feet unaudited (sqft)			2,314,000
National Pension Service of Korea / Hines Interest LP | Joint venture | One Vanderbilt Avenue
General information on each joint venture
Ownership Interest			71.01%
Economic Interest (as a percent)			71.01%
Approximate Square Feet unaudited (sqft)			1,657,198
RXR Realty / New York REIT | Joint venture | Worldwide Plaza
General information on each joint venture
Ownership Interest			24.95%
Economic Interest (as a percent)			24.95%
Approximate Square Feet unaudited (sqft)			2,048,725
Allianz Real Estate of America | Joint venture | 1515 Broadway
General information on each joint venture
Ownership Interest			56.87%
Economic Interest (as a percent)			56.87%
Approximate Square Feet unaudited (sqft)			1,750,000
Israeli Institutional Investor | Joint venture | 2 Herald Square
General information on each joint venture
Ownership Interest			95%
Economic Interest (as a percent)			95%
Approximate Square Feet unaudited (sqft)			369,000
A fund managed by Meritz Alternative Investment Management | Joint venture | 15 Beekman
General information on each joint venture
Ownership Interest			20%
Economic Interest (as a percent)			20%
Approximate Square Feet unaudited (sqft)			221,884
A fund managed by Meritz Alternative Investment Management | Joint venture | 220 East 42nd Street
General information on each joint venture
Ownership Interest			51%
Economic Interest (as a percent)			51%
Approximate Square Feet unaudited (sqft)			1,135,000
Wells Fargo | Joint venture | 85 Fifth Avenue
General information on each joint venture
Ownership Interest			36.27%
Economic Interest (as a percent)			36.27%
Approximate Square Feet unaudited (sqft)			12,946
National Pension Service of Korea / Hines Interest LP / International Investor | One Madison Avenue
General information on each joint venture
Investment in joint venture aggregate maximum ownership percentage							25%
National Pension Service of Korea / Hines Interest LP / International Investor | Joint venture | One Madison Avenue
General information on each joint venture
Ownership Interest			25.50%
Economic Interest (as a percent)			25.50%
Approximate Square Feet unaudited (sqft)			1,048,700
Korean Institutional Investor / Israeli Institutional Investor | 450 Park Avenue | Third-Party
General information on each joint venture
Ownership Interest			49.90%
Investment in joint venture, partners' ownership percentage			25%
Korean Institutional Investor / Israeli Institutional Investor | Joint venture | 450 Park Avenue
General information on each joint venture
Ownership Interest			50.10%
Economic Interest (as a percent)			25.10%
Approximate Square Feet unaudited (sqft)			337,000
Investment in joint venture, ownership percentage			25.10%
RXR Realty led investment group | Joint venture | 5 Times Square
General information on each joint venture
Ownership Interest			31.55%
Economic Interest (as a percent)			31.55%
Approximate Square Feet unaudited (sqft)			1,131,735
U.S. Affiliate of Mori Trust Co., Ltd | Joint venture | 245 Park Avenue
General information on each joint venture
Ownership Interest			50.10%
Economic Interest (as a percent)			50.10%
Approximate Square Feet unaudited (sqft)			1,782,793
Private Investor | Joint venture | 625 Madison Avenue
General information on each joint venture
Ownership Interest		90.43%	90.43%
Approximate Square Feet unaudited (sqft)			563,000

Investments in Unconsolidated_5

Investments in Unconsolidated Joint Ventures - Schedule of Investments in Unconsolidated Joint Ventures Sold (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2024	Mar. 31, 2024	Mar. 31, 2023
Schedule of Equity Method Investments [Line Items]
Loss on Sale		$ 26,764	$ (79)
717 Fifth Avenue | Joint venture | Wharton Properties
Schedule of Equity Method Investments [Line Items]
Ownership Interest Sold	10.92%
Gross Asset Valuation	$ 963,000
Loss on Sale	$ 26,900

Investments in Unconsolidated_6

Investments in Unconsolidated Joint Ventures - Schedule of Mortgage Notes and Other Loans Payable Collateralized by the Respective Joint Venture Properties and Assignment of Leases (Details)	1 Months Ended	3 Months Ended
	Apr. 30, 2024 USD ($)	Mar. 31, 2024 USD ($) extension	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Total fixed rate debt		$ 1,590,885,000	$ 1,387,386,000
Total floating rate debt		110,493,000	110,000,000
Joint venture
Debt Instrument [Line Items]
Total fixed rate debt		11,316,927,000	12,000,559,000
Total floating rate debt		2,601,226,000	2,902,780,000
Total fixed rate and floating rate debt		13,918,153,000	14,903,339,000
Deferred financing costs, net		(93,904,000)	(104,062,000)
Total joint venture mortgages and other loans payable, net		13,824,249,000	14,799,277,000
Joint venture | Mortgage loan | Subsequent Event
Debt Instrument [Line Items]
Debt instrument face amount	$ 1,075,000,000
Joint venture | Mortgage loan | Subsequent Event | Mezzanine Loan
Debt Instrument [Line Items]
Debt instrument face amount	125,000,000
Repayments of debt	$ 62,500,000
Joint venture | Mortgage loan | Subsequent Event | SOFR
Debt Instrument [Line Items]
Interest rate added to base rate (as a percent)	1.78%
Debt instrument, fixed interest rate, (as a percent)	5.91%
Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		5,905,180,000	6,053,808,000
Total floating rate debt		1,182,168,000	1,298,467,000
Total fixed rate and floating rate debt		7,087,348,000	7,352,275,000
Deferred financing costs, net		(50,598,000)	(54,865,000)
Total joint venture mortgages and other loans payable, net		$ 7,036,750,000	7,297,410,000
220 East 42nd Street | A fund managed by Meritz Alternative Investment Management | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		51%
Interest rate, fixed rate debt (as a percent)		5.86%
Total fixed rate debt		$ 505,412,000	505,412,000
220 East 42nd Street | A fund managed by Meritz Alternative Investment Management | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 257,760,000	257,760,000
650 Fifth Avenue | Wharton Properties | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		50%
Interest rate, fixed rate debt (as a percent)		5.45%
Interest rate, floating rate debt (as a percent)		2.25%
Total fixed rate debt		$ 65,000,000	65,000,000
Total floating rate debt		210,000,000	210,000,000
650 Fifth Avenue | Wharton Properties | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		32,500,000	32,500,000
Total floating rate debt		$ 105,000,000	105,000,000
5 Times Square | RXR Realty led investment group | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		31.55%
Interest rate, fixed rate debt (as a percent)		7.18%
Interest rate, floating rate debt (as a percent)		5.61%
Total fixed rate debt		$ 514,897,000	477,783,000
Total floating rate debt		615,094,000	610,010,000
5 Times Square | RXR Realty led investment group | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		162,450,000	150,740,000
Total floating rate debt		$ 194,062,000	192,458,000
1515 Broadway | Allianz Real Estate of America | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		56.87%
Interest rate, fixed rate debt (as a percent)		3.93%
Total fixed rate debt		$ 756,777,000	762,002,000
1515 Broadway | Allianz Real Estate of America | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 430,371,000	433,344,000
115 Spring Street | Private Investors | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		51%
Interest rate, fixed rate debt (as a percent)		5.50%
Total fixed rate debt		$ 65,550,000	65,550,000
115 Spring Street | Private Investors | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 33,431,000	33,431,000
450 Park Avenue | Korean Institutional Investor / Israeli Institutional Investor | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		25.10%
Interest rate, fixed rate debt (as a percent)		6.10%
Total fixed rate debt		$ 273,616,000	271,394,000
450 Park Avenue | Korean Institutional Investor / Israeli Institutional Investor | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 68,678,000	68,120,000
11 Madison Avenue | PGIM Real Estate | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		60%
Interest rate, fixed rate debt (as a percent)		3.84%
Total fixed rate debt		$ 1,400,000,000	1,400,000,000
11 Madison Avenue | PGIM Real Estate | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		840,000,000	840,000,000
One Madison Avenue | Joint venture | Construction Loans
Debt Instrument [Line Items]
Maximum facility capacity		$ 1,250,000,000
Term		5 years
Number of extension options | extension		1
Period of extension options		1 year
One Madison Avenue | National Pension Service of Korea / Hines Interest LP / International Investor | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		25.50%
Interest rate, fixed rate debt (as a percent)		3.59%
Total fixed rate debt		$ 769,105,000	733,103,000
One Madison Avenue | National Pension Service of Korea / Hines Interest LP / International Investor | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 196,122,000	186,941,000
15 Beekman | A fund managed by Meritz Alternative Investment Management | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		20%
Interest rate, fixed rate debt (as a percent)		5.99%
Interest rate, floating rate debt (as a percent)
Total fixed rate debt		$ 120,000,000	0
Total floating rate debt		0	124,137,000
15 Beekman | A fund managed by Meritz Alternative Investment Management | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		24,000,000	0
Total floating rate debt		$ 0	24,827,000
800 Third Avenue | Private Investors | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		60.52%
Interest rate, fixed rate debt (as a percent)		3.37%
Total fixed rate debt		$ 177,000,000	177,000,000
800 Third Avenue | Private Investors | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 107,120,000	107,120,000
919 Third Avenue | New York State Teacher's Retirement System | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		51%
Interest rate, fixed rate debt (as a percent)		6.11%
919 Third Avenue | New York State Teacher's Retirement System | Joint venture | Mortgage loan
Debt Instrument [Line Items]
Total fixed rate debt		$ 500,000,000	500,000,000
919 Third Avenue | New York State Teacher's Retirement System | Joint venture | Common Stock | Mortgage loan
Debt Instrument [Line Items]
Total fixed rate debt		$ 255,000,000	255,000,000
625 Madison Avenue | Winthrop Capital Advisors | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		90.43%
Interest rate, fixed rate debt (as a percent)		5.07%
Total fixed rate debt		$ 201,570,000	199,987,000
625 Madison Avenue | Winthrop Capital Advisors | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 182,280,000	180,848,000
245 Park Avenue | U.S. Affiliate of Mori Trust Co., Ltd | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		50.10%
Interest rate, fixed rate debt (as a percent)		4.30%
Total fixed rate debt		$ 1,768,000,000	1,768,000,000
245 Park Avenue | U.S. Affiliate of Mori Trust Co., Ltd | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 885,768,000	885,768,000
Worldwide Plaza | RXR Realty / New York REIT | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		24.95%
Interest rate, fixed rate debt (as a percent)		3.98%
Total fixed rate debt		$ 1,200,000,000	1,200,000,000
Worldwide Plaza | RXR Realty / New York REIT | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 299,400,000	299,400,000
One Vanderbilt Avenue | National Pension Service of Korea / Hines Interest LP | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		71.01%
Interest rate, fixed rate debt (as a percent)		2.95%
Total fixed rate debt		$ 3,000,000,000	3,000,000,000
One Vanderbilt Avenue | National Pension Service of Korea / Hines Interest LP | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		2,130,300,000	2,130,300,000
10 East 53rd Street
Debt Instrument [Line Items]
Total fixed rate debt		$ 205,000,000	0
10 East 53rd Street | Canadian Pension Plan Investment Board | Joint venture
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)
Total fixed rate debt		$ 0	220,000,000
10 East 53rd Street | Canadian Pension Plan Investment Board | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 0	121,000,000
717 Fifth Avenue | Wharton Properties / Private Investor | Joint venture
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)
Total fixed rate debt		$ 0	655,328,000
717 Fifth Avenue | Wharton Properties / Private Investor | Joint venture | Common Stock
Debt Instrument [Line Items]
Total fixed rate debt		$ 0	71,536,000
11 West 34th Street | Private Investor / Wharton Properties | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		30%
Interest rate, floating rate debt (as a percent)		1.45%
Total floating rate debt		$ 23,000,000	23,000,000
11 West 34th Street | Private Investor / Wharton Properties | Joint venture | Common Stock
Debt Instrument [Line Items]
Total floating rate debt		$ 6,900,000	6,900,000
1552 Broadway | Wharton Properties | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		50%
Interest rate, floating rate debt (as a percent)		2.75%
Total floating rate debt		$ 193,132,000	193,133,000
1552 Broadway | Wharton Properties | Joint venture | Common Stock
Debt Instrument [Line Items]
Total floating rate debt		$ 96,566,000	96,567,000
100 Park Avenue | Prudential Real Estate Investors | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		49.90%
Interest rate, floating rate debt (as a percent)		2.36%
Total floating rate debt		$ 360,000,000	360,000,000
100 Park Avenue | Prudential Real Estate Investors | Joint venture | Common Stock
Debt Instrument [Line Items]
Total floating rate debt		$ 179,640,000	179,640,000
280 Park Avenue | Vornado Realty Trust | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		50%
Interest rate, floating rate debt (as a percent)		2.03%
Total floating rate debt		$ 1,200,000,000	1,200,000,000
280 Park Avenue | Vornado Realty Trust | Joint venture | Common Stock
Debt Instrument [Line Items]
Total floating rate debt		$ 600,000,000	600,000,000
2 Herald Square | Israeli Institutional Investor | Joint venture
Debt Instrument [Line Items]
Economic Interest (as a percent)		95%
Interest rate, floating rate debt (as a percent)
Total floating rate debt		$ 0	182,500,000
2 Herald Square | Israeli Institutional Investor | Joint venture | Common Stock
Debt Instrument [Line Items]
Total floating rate debt		0	$ 93,075,000
625 Madison Avenue | Private Investors | Joint venture
Debt Instrument [Line Items]
Debt instrument face amount		170,500,000
Debt instrument, increase, accrued interest		$ 31,100,000

Investments in Unconsolidated_7

Investments in Unconsolidated Joint Ventures - Schedules of Combined Financial Statements for the Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Assets
Commercial real estate property, net		$ 5,114,449		$ 5,020,789
Cash and restricted cash		196,035	$ 158,937	221,823
Tenant and other receivables, related party receivables, and deferred rents receivable		38,659		33,270
Other assets		533,802		413,670
Total assets	[1]	9,764,292		9,531,181
Liabilities and equity
Mortgages and other loans payable, net		1,695,163		1,491,319
Lease liability - operating leases		823,594		827,692
Other liabilities		437,302		471,401
Equity		3,803,648	4,529,174	3,855,925	$ 4,646,922
Total liabilities and equity		9,764,292		9,531,181
Company's investments in unconsolidated joint ventures		2,984,786		2,983,313
Investments difference between carrying amount and underlying equity		548,200
Combined statements of income for the unconsolidated joint ventures
Total revenues		187,882	245,764
Operating expenses		43,608	52,064
Real estate taxes		31,606	41,383
Operating lease rent		6,405	6,301
Interest expense, net of interest income		31,173	41,653
Amortization of deferred financing costs		1,539	2,021
Depreciation and amortization		48,584	78,782
Total expenses		204,807	275,218
Net income (loss)		18,389	(38,357)
Company's equity in net income (loss) from unconsolidated joint ventures		111,160	(7,412)
Joint venture
Assets
Commercial real estate property, net		18,024,642		18,467,340
Cash and restricted cash		608,462		656,038
Tenant and other receivables, related party receivables, and deferred rents receivable		634,813		673,532
Other assets		2,538,878		2,584,765
Total assets		21,806,795		22,381,675
Liabilities and equity
Mortgages and other loans payable, net		13,824,249		14,799,277
Deferred revenue		1,070,740		1,108,180
Lease liability - operating leases		987,299		990,276
Other liabilities		430,533		447,705
Equity		5,493,974		5,036,237
Total liabilities and equity		21,806,795		$ 22,381,675
Company's investments in unconsolidated joint ventures		2,984,786
Combined statements of income for the unconsolidated joint ventures
Total revenues		365,339	389,452
Operating expenses		65,750	61,968
Real estate taxes		75,632	65,740
Operating lease rent		9,025	7,181
Interest expense, net of interest income		149,854	129,477
Amortization of deferred financing costs		6,072	7,045
Depreciation and amortization		134,178	125,266
Total expenses		440,511	396,677
Gain on early extinguishment of debt		172,519	0
Net income (loss)		97,347	(7,225)
Company's equity in net income (loss) from unconsolidated joint ventures		$ 111,160	$ (7,412)
[1] (1) The Company's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $120.4 million and $41.2 million of land, $81.3 million and $40.5 million of building and improvements, $— million and $— million of building and leasehold improvements, $— million and $— million of right of use assets, $5.7 million and $5.4 million of accumulated depreciation, $785.1 million and $676.9 million of other assets included in other line items, $254.3 million and $50.0 million of real estate debt, net, $2.7 million and $0.9 million of accrued interest payable, $— million and $— million of lease liabilities, and $332.5 million and $306.5 million of other liabilities included in other line items as of March 31, 2024 and December 31, 2023, respectively.

Deferred Costs (Details)

Deferred Costs (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing costs	$ 402,025	$ 399,224
Less: accumulated amortization	(292,729)	(287,761)
Deferred costs, net	$ 109,296	$ 111,463

Mortgages and Other Loans Pay_3

Mortgages and Other Loans Payable - Schedule of Mortgages and Other Loans Payable (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Total fixed rate debt	$ 1,590,885		$ 1,387,386
Total floating rate debt	110,493		110,000
Total mortgages and other loans payable	1,701,378		1,497,386
Deferred financing costs, net of amortization	(6,215)		(6,067)
Total mortgages and other loans payable, net	1,695,163		1,491,319
Repayments of mortgages	1,501	$ 1,473
420 Lexington Ave
Debt Instrument [Line Items]
Total fixed rate debt	275,737		277,238
10 East 53rd Street
Debt Instrument [Line Items]
Total fixed rate debt	205,000		0
100 Church Street
Debt Instrument [Line Items]
Total fixed rate debt	370,000		370,000
7 Dey / 185 Broadway
Debt Instrument [Line Items]
Total fixed rate debt	190,148		190,148
Landmark Square
Debt Instrument [Line Items]
Total fixed rate debt	100,000		100,000
485 Lexington Avenue
Debt Instrument [Line Items]
Total fixed rate debt	450,000		450,000
690 Madison Avenue
Debt Instrument [Line Items]
Total floating rate debt	60,493		60,000
719 Seventh Avenue
Debt Instrument [Line Items]
Total floating rate debt	50,000		$ 50,000
Total mortgages and other loans payable, net	50,000
Repayments of mortgages	$ 32,000
Weighted Average | 420 Lexington Ave
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	3.99%
Weighted Average | 10 East 53rd Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.45%
Weighted Average | 100 Church Street
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	5.89%
Weighted Average | 7 Dey / 185 Broadway
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	6.65%
Weighted Average | Landmark Square
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.90%
Weighted Average | 485 Lexington Avenue
Debt Instrument [Line Items]
Interest rate, fixed rate debt (as a percent)	4.25%
Weighted Average | 690 Madison Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	0.50%
Weighted Average | 719 Seventh Avenue
Debt Instrument [Line Items]
Interest rate, floating rate debt (as a percent)	1.31%

Mortgages and Other Loans Pay_4

Mortgages and Other Loans Payable - Narrative (Details) - USD ($) $ in Billions	Mar. 31, 2024	Dec. 31, 2023
Mortgages and Other Loans Payable
Book value of collateral	$ 2	$ 1.9

Corporate Indebtedness - Additi

Corporate Indebtedness - Additional Information (Details)	3 Months Ended
	Mar. 31, 2024 USD ($) extension	Dec. 31, 2023 USD ($)
Corporate Indebtedness
Revolving credit facility, net	$ 645,138,000	$ 554,752,000
Term Loan A, Maturity May 2026 | Term Loan
Corporate Indebtedness
Maximum facility capacity	$ 1,050,000,000
Term Loan A, Maturity May 2026 | SOFR | Term Loan
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.60%
Term Loan A, Maturity May 2026 | SOFR | Minimum | Term Loan
Corporate Indebtedness
Interest rate added to base rate (as a percent)	0.80%
Term Loan A, Maturity May 2026 | SOFR | Maximum | Term Loan
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.60%
Term Loan B, Maturity November 2024 | Term Loan
Corporate Indebtedness
Maximum facility capacity	$ 200,000,000
Term Loan B, Maturity November 2024 | SOFR | Term Loan
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.65%
Term Loan B, Maturity November 2024 | SOFR | Minimum | Term Loan
Corporate Indebtedness
Interest rate added to base rate (as a percent)	0.85%
Term Loan B, Maturity November 2024 | SOFR | Maximum | Term Loan
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.65%
Revolving Credit Facility
Corporate Indebtedness
Facility fee (as a percent)	0.30%
Revolving credit facility, net	$ 650,000,000
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%
Term Loan
Corporate Indebtedness
Long-term debt, carrying value	$ 1,250,000,000
Term Loan | Line of Credit
Corporate Indebtedness
Long-term debt, carrying value	1,200,000,000	1,200,000,000
Credit Facility 2017
Corporate Indebtedness
Letters of credit	0
2012 Credit Facility
Corporate Indebtedness
Ability to borrow under line of credit facility	600,000,000
2012 Credit Facility | Line of Credit
Corporate Indebtedness
Long-term debt, carrying value	$ 645,100,000	$ 554,800,000
Revolving Credit Facility | SOFR | Line of Credit
Corporate Indebtedness
Interest rate added to base rate (as a percent)	0.10%
Revolving Credit Facility | Revolving Credit Facility, Maturity May 2026 | Line of Credit
Corporate Indebtedness
Maximum facility capacity	$ 1,250,000,000
Number of extensions | extension	2
Term of extension	6 months
Maximum borrowing capacity, optional expansion	$ 4,500,000,000
Revolving Credit Facility | Revolving Credit Facility, Maturity May 2026 | SOFR | Line of Credit
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.40%
Revolving Credit Facility | Revolving Credit Facility, Maturity May 2026 | SOFR | Minimum | Line of Credit
Corporate Indebtedness
Interest rate added to base rate (as a percent)	0.725%
Revolving Credit Facility | Revolving Credit Facility, Maturity May 2026 | SOFR | Maximum | Line of Credit
Corporate Indebtedness
Interest rate added to base rate (as a percent)	1.40%

Corporate Indebtedness - Schedu

Corporate Indebtedness - Schedule of Senior Unsecured Notes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt disclosures by scheduled maturity date
Accreted Balance	$ 1,245,382	$ 1,244,881
Senior unsecured notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	100,000
Accreted Balance	100,000	100,000
Deferred financing costs, net	(180)	(205)
Accreted Balance, net of deferred financing costs	99,820	99,795
Senior unsecured notes | 4.27% Senior unsecured notes maturing on December 17, 2025
Debt disclosures by scheduled maturity date
Unpaid Principal Balance	100,000
Accreted Balance	$ 100,000	$ 100,000
Coupon Rate (as a percent)	4.27%
Initial Term (in Years)	10 years

Corporate Indebtedness - Sche_2

Corporate Indebtedness - Schedule of Junior Subordinated Deferrable Interest Debentures and Principal Maturities (Details)	1 Months Ended
	Jun. 30, 2005 USD ($) quarter	Mar. 31, 2024 USD ($)
Principal Repayments and Joint Venture Debt
Remaining 2024		$ 586,230,000
2025		470,000,000
2026		190,148,000
2027		2,250,000,000
2028		205,000,000
Thereafter		100,000,000
Total principal repayments		3,801,378,000
Trust Preferred Securities
Debt Instrument [Line Items]
Proceeds from issuance of debt	$ 100,000,000
Trust Preferred Securities | SOFR
Debt Instrument [Line Items]
Interest rate added to base rate (as a percent)	0.26%
Interest payment deferment, number of consecutive quarters | quarter	8
Joint venture
Principal Repayments and Joint Venture Debt
Remaining 2024		1,488,241,000
2025		1,739,239,000
2026		544,400,000
2027		1,185,168,000
2028		0
Thereafter		2,130,300,000
Total principal repayments		7,087,348,000
Joint venture | Mortgages and other loans payable
Scheduled Amortization
Remaining 2024		2,987,000
2025		0
2026		0
2027		0
2028		0
Thereafter		0
Total amortization of debt		2,987,000
Principal Repayments and Joint Venture Debt
Remaining 2024		383,243,000
2025		370,000,000
2026		190,148,000
2027		550,000,000
2028		205,000,000
Thereafter		0
Total principal repayments		1,698,391,000
Joint venture | Revolving Credit Facility
Principal Repayments and Joint Venture Debt
Remaining 2024		0
2025		0
2026		0
2027		650,000,000
2028		0
Thereafter		0
Total principal repayments		650,000,000
Joint venture | Unsecured Term Loans
Principal Repayments and Joint Venture Debt
Remaining 2024		200,000,000
2025		0
2026		0
2027		1,050,000,000
2028		0
Thereafter		0
Total principal repayments		1,250,000,000
Joint venture | Trust Preferred Securities
Principal Repayments and Joint Venture Debt
Remaining 2024		0
2025		0
2026		0
2027		0
2028		0
Thereafter		100,000,000
Total principal repayments		100,000,000
Joint venture | Senior Unsecured Notes
Principal Repayments and Joint Venture Debt
Remaining 2024		0
2025		100,000,000
2026		0
2027		0
2028		0
Thereafter		0
Total principal repayments		$ 100,000,000

Corporate Indebtedness - Sche_3

Corporate Indebtedness - Schedule of Consolidated Interest Expense, Excluding Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest expense
Interest expense before capitalized interest	$ 48,869	$ 64,843
Interest on financing leases	1,120	1,106
Capitalized interest	(17,949)	(25,464)
Amortization of discount on assumed debt	0	1,487
Interest income	(867)	(319)
Interest expense, net	$ 31,173	$ 41,653

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Apr. 30, 2024	Dec. 31, 2016	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2022	Dec. 31, 2023
Related Party Transactions
Operating lease rent			$ 6,405	$ 6,301
Rental revenue, net			141,504	195,042
Related party receivables			12,229			$ 12,168
Joint venture
Related Party Transactions
Operating lease rent			9,025	7,181
Related party receivables			10,619			10,603
Other Affiliates
Related Party Transactions
Related party receivables			1,610			1,565
Related party
Related Party Transactions
Related party receivables			12,229			$ 12,168
One Vanderbilt Avenue
Related Party Transactions
Operating lease rent			700	700
SUMMIT One Vanderbilt
Related Party Transactions
Operating lease rent			6,300	4,100
Rental revenue, net			$ 6,300	$ 4,100
Holiday | Payment of Interest Acquired | One Vanderbilt Avenue
Related Party Transactions
Stabilization of property, liquidation value, amount monetized		$ 1,400
Holiday | Property Interest Liquidation | One Vanderbilt Avenue
Related Party Transactions
Stabilization of property, liquidation value, amount monetized					$ 17,900
Mathias | 719 Seventh Avenue | Related party | Subsequent Event
Related Party Transactions
Proceeds from sale of property	$ 30,500
Expected equity ownership percentage	40%
Equity interest held by partner	$ 7,000
Mathias | Payment of Interest Acquired | One Vanderbilt Avenue
Related Party Transactions
Stabilization of property, liquidation value, amount monetized		$ 1,000
Mathias | Property Interest Liquidation | One Vanderbilt Avenue
Related Party Transactions
Stabilization of property, liquidation value, amount monetized					$ 11,900
Holiday And Mathias | One Vanderbilt Avenue
Related Party Transactions
Stabilization of property, within three years after stabilization, percent					50%
Stabilization period			3 years
Stabilization of property, three years or more after stabilization, percent			100%
Stabilization of property, anniversary period			7 years
Minimum | Holiday | One Vanderbilt Avenue
Related Party Transactions
Percentage of profits due to investors (as a percentage)		1.27%
Minimum | Mathias | One Vanderbilt Avenue
Related Party Transactions
Percentage of profits due to investors (as a percentage)		1.92%
Maximum | Holiday | One Vanderbilt Avenue
Related Party Transactions
Percentage of profits due to investors (as a percentage)		0.85%
Maximum | Mathias | One Vanderbilt Avenue
Related Party Transactions
Percentage of profits due to investors (as a percentage)		1.28%

Noncontrolling Interests on t_3

Noncontrolling Interests on the Company's Consolidated Financial Statements - Additional Information (Details) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2023 shares
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Redemption and conversion of common units | $	$ (5,674)
Net income (loss) | $	901	$ (2,337)
Accumulated other comprehensive income (loss) allocation | $	$ 1,622	(1,851)
SL Green Operating Partnership
Organization
Number of units of operating partnership owned by the noncontrolling interest unit holders (shares)	4,417,247			3,949,448
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Redemption and conversion of common units | $	$ (5,674)
Accumulated other comprehensive income (loss) allocation | $	$ 1,622	(1,851)
SL Green Operating Partnership | Series A
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	5%
Number of Units Authorized (in shares)	109,161
Number of Units Issued (in shares)	109,161
Number of Units Outstanding (in shares)	109,161
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 50
Liquidation Preference Per Unit (in dollars per share) | $ / shares	1,000
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
Number of company common stock issued on conversion of Series B preferred units	6.71348
SL Green Operating Partnership | Series F
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	7%
Number of Units Authorized (in shares)	60
Number of Units Issued (in shares)	60
Number of Units Outstanding (in shares)	60
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 70
Liquidation Preference Per Unit (in dollars per share) | $ / shares	1,000
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 29.12
SL Green Operating Partnership | Series K
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	3.50%
Number of Units Authorized (in shares)	700,000
Number of Units Issued (in shares)	563,954
Number of Units Outstanding (in shares)	341,677
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 0.8750
Liquidation Preference Per Unit (in dollars per share) | $ / shares	25
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 134.67
SL Green Operating Partnership | Series L
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	4%
Number of Units Authorized (in shares)	500,000
Number of Units Issued (in shares)	378,634
Number of Units Outstanding (in shares)	372,634
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 1
Liquidation Preference Per Unit (in dollars per share) | $ / shares	25
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
SL Green Operating Partnership | Series R
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	3.50%
Number of Units Authorized (in shares)	400,000
Number of Units Issued (in shares)	400,000
Number of Units Outstanding (in shares)	400,000
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 0.8750
Liquidation Preference Per Unit (in dollars per share) | $ / shares	25
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 154.89
SL Green Operating Partnership | Series S
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	4%
Number of Units Authorized (in shares)	1,077,280
Number of Units Issued (in shares)	1,077,280
Number of Units Outstanding (in shares)	1,077,280
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 1
Liquidation Preference Per Unit (in dollars per share) | $ / shares	25
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
SL Green Operating Partnership | Series V
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	5%
Number of Units Authorized (in shares)	40,000
Number of Units Issued (in shares)	40,000
Number of Units Outstanding (in shares)	40,000
Annual Dividend Per Unit (in dollars per share) | $ / shares	$ 1.2500
Liquidation Preference Per Unit (in dollars per share) | $ / shares	25
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
SL Green Operating Partnership | Series W
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Number of Units Authorized (in shares)	1
Number of Units Issued (in shares)	1
Number of Units Outstanding (in shares)	1
Preferred stock, dividend, multiplier per common unit distribution	1,350
SL Green Operating Partnership | Series B Preferred Stock
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Convertible preferred stock, shares issued upon conversion (in shares)	1
Partnership Interest
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Balance at beginning of period | $	$ 238,051	$ 269,993
Distributions | $	(3,609)		$ (14,779)
Issuance of common units | $	6,025		25,365
Redemption and conversion of common units | $	(13,596)		(18,589)
Net income (loss) | $	901		(37,465)
Accumulated other comprehensive income (loss) allocation | $	1,622		(1,960)
Fair value adjustment | $	42,841		15,486
Balance at end of period | $	$ 272,235		$ 269,993
Operating Partnership | SL Green Operating Partnership
Organization
Noncontrolling interest in the operating partnership (as a percent)	6.38%			5.75%

Noncontrolling Interests on t_4

Noncontrolling Interests on the Company's Consolidated Financial Statements - Schedule of Common Unit Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2022
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	$ (5,674)
SL Green Operating Partnership
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	(5,674)
SL Green Operating Partnership | Preferred stock
Rollforward Analysis of Preferred Unit Activity
Balance at beginning of period	166,501
Issuance of preferred units	0	$ 0
Redemption of preferred units	0	(11,700)
Dividends paid on preferred units	(1,920)	(6,271)
Accrued dividends on preferred units	1,920	6,529
Balance at end of period	$ 166,501	$ 177,943

Stockholders' Equity of the C_3

Stockholders' Equity of the Company - Additional Information (Details) - $ / shares	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Equity, Class of Treasury Stock [Line Items]
Authorized capital stock (shares)	260,000,000
Authorized shares, par value (in dollars per share)	$ 0.01
Common stock, shares authorized (in shares)	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
Excess shares issued (shares)	0
Excess shares outstanding (in shares)	0
Common Stock
Equity, Class of Treasury Stock [Line Items]
Shares, outstanding (in shares)	64,806,000	64,726,000	64,373,000	64,380,000
SL Green Operating Partnership | Common Stock
Equity, Class of Treasury Stock [Line Items]
Shares, outstanding (in shares)	64,805,510
Shares, issued (in shares)	64,805,510

Stockholders' Equity of the C_4

Stockholders' Equity of the Company - Stock Repurchase Program (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) increase $ / shares shares	Dec. 31, 2023 $ / shares shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Aug. 31, 2016 USD ($)
Class of Stock [Line Items]
Share repurchased (in shares) | shares	0	0
Average price paid per share (in dollars per share) | $ / shares	$ 0	$ 0
2016 Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount | $			$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 1,000,000,000
Number of increases to share repurchase program | increase	5
Stock repurchase program, authorized amount | $	$ 3,500,000,000
Share repurchased (in shares) | shares	36,107,719	36,107,719

Stockholders' Equity of the C_5

Stockholders' Equity of the Company - At-the-Market Equity Offering Program and Perpetual Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Aug. 31, 2012	Mar. 31, 2024	Feb. 29, 2024	Dec. 31, 2023
Stockholders' Equity
Common stock, shares authorized (in shares)		160,000,000		160,000,000
Series I Preferred Stock
Stockholders' Equity
Preferred stock, shares outstanding (in shares)		9,200,000		9,200,000
Preferred stock, distribution rate		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	$ 221.9
Dividend Reinvestment and Stock Purchase Plan (DRIP)
Stockholders' Equity
Common stock, shares authorized (in shares)			3,500,000

Stockholders' Equity of the C_6

Stockholders' Equity of the Company - Schedule of Common Stock Issued and Proceeds Received Dividend Reinvestments (Details) - Dividend Reinvestment and Stock Purchase Plan (DRIP) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stockholders' Equity
Shares of common stock issued (in shares)	1,662	5,280
Dividend reinvestments/stock purchases under the DRSPP	$ 77	$ 184

Stockholders' Equity of the C_7

Stockholders' Equity of the Company - Earnings per Share (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Basic Earnings:
Income (loss) attributable to SL Green common stockholders	$ 13,141	$ (39,731)
Less: distributed earnings allocated to participating securities	(434)	(406)
Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit)	12,707	(40,137)
Effect of Dilutive Securities:
Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares	434	0
Add back: effect of dilutive securities (redemption of units to common shares)	901	(2,837)
Diluted Earnings:
Net (loss) income attributable to SL Green common stockholders, diluted	$ 14,042	$ (42,974)
Basic Shares:
Weighted average common shares outstanding (shares)	64,328,000	64,079,000
Effect of Dilutive Securities:
Operating Partnership units redeemable for common shares (shares)	4,439,000	4,103,000
Stock-based compensation plans (shares)	1,328,000	0
Diluted weighted average common stock outstanding (shares)	70,095,000	68,182,000
Common stock shares excluded from the diluted shares outstanding (shares)	135,000	1,275,225

Partners' Capital of the Oper_3

Partners' Capital of the Operating Partnership - Additional Information (Details) - shares	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Common Stock
Stockholders' Equity
Units outstanding (units)	64,806,000	64,726,000	64,373,000	64,380,000
SL Green Operating Partnership
Stockholders' Equity
Number of units of operating partnership owned by the noncontrolling interest unit holders (units)	4,417,247	3,949,448
SL Green Operating Partnership | Operating Partnership
Stockholders' Equity
Noncontrolling interest in the operating partnership (as a percent)	6.38%	5.75%
SL Green Operating Partnership | Common Stock
Stockholders' Equity
Shares, issued (in shares)	64,805,510
Units outstanding (units)	64,805,510
SL Green Operating Partnership | Series I Preferred Units
Stockholders' Equity
Units outstanding (units)	9,200,000
Period of restriction to redeem OP Units	1 year
Conversion of stock, shares issued	1

Partners' Capital of the Oper_4

Partners' Capital of the Operating Partnership - EPS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator
Less: distributed earnings allocated to participating securities	$ (434)	$ (406)
Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit)	12,707	(40,137)
Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares	(434)	0
Net (loss) income attributable to SL Green common stockholders, diluted	$ 14,042	$ (42,974)
Denominator
Common stock shares excluded from the diluted shares outstanding (shares)	135,000	1,275,225
SL Green Operating Partnership
Numerator
Net income (loss) attributable to SLGOP common unitholders (numerator for diluted earnings per unit)	$ 14,042	$ (42,068)
Less: distributed earnings allocated to participating securities	(434)	(906)
Net income (loss) attributable to SLGOP common unitholders (numerator for basic earnings per unit)	13,608	(42,974)
Add back: dilutive effect of earnings allocated to participating securities and contingently issuable shares	434	0
Net (loss) income attributable to SL Green common stockholders, diluted	$ 14,042	$ (42,974)
Denominator
Basic weighted average common units outstanding (in shares)	68,767,000	68,182,000
Stock-based compensation plans (shares)	1,328,000	0
Diluted weighted average common units outstanding (shares)	70,095,000	68,182,000
Common stock shares excluded from the diluted shares outstanding (shares)	135,000	1,275,225

Share-based Compensation - Addi

Share-based Compensation - Additional Information (Details)		3 Months Ended		12 Months Ended
	Jan. 01, 2008 shares	Mar. 31, 2024 USD ($) unit / shares unit fungibleUnit shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares
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		$ 300,000	$ 400,000
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
Expected term		10 years
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
Options granted (in shares) | shares		0		0
Remaining weighted average contractual life of the options outstanding (in years)		2 years 8 months 12 days
Remaining average contractual life of the options exercisable (in years)		2 years 8 months 12 days
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
Class O LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred unit distributions as a percentage of common unit distributions		10%
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 2,625,319			$ 7,766,055
Total unrecognized compensation cost related to unvested stock awards		$ 17,300,000
Annual award vesting rate, low end of range (as a percent)		15%
Annual award vesting rate, high end of range (as a percent)		35%
Fair value of restricted stock vested during the period		$ 7,100,000		$ 10,200,000
Weighted average period for recognition of compensation cost related to unvested stock awards (in years)		2 years 2 months 12 days
Weighted average fair value of options granted during the period		$ 151,901			$ 15,789,540
Awards granted (in shares) | shares		3,234			337,350
Awards outstanding (in shares) | shares		4,084,958		4,089,174	3,758,174
LTIP units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of options granted during the period		$ 23,700,000		$ 38,100,000
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		6,200,000	10,000,000
Total unrecognized compensation cost related to unvested stock awards		$ 42,100,000
Weighted average period for recognition of compensation cost related to unvested stock awards (in years)		1 year 9 months 18 days
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) | unit		32,210,000
Fungible units per share (in fungible units per share) | unit / shares		2.59
Shares that may be issued if equal to fungible units (shares) (less than) | shares		32,210,000
Fungible units | fungibleUnit		3,000,000
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		$ 0	0
Total unrecognized compensation cost related to unvested stock awards		$ 0
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		0.84
Award expiration period (in years)		5 years
Deferred Stock Compensation Plan for Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 2,100,000	$ 2,100,000
Maximum percentage of the annual retainer fee, chairman fees and meeting fees that may be deferred by non-employee directors (percent)		100%
Awards granted (in shares) | shares		15,945
Shares issued (in shares) | shares		25,590
Awards outstanding (in shares) | shares		125,654
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
Discount from market price	85%
Shares of common stock issued (shares) | shares		217,081

Share-based Compensation - Stoc

Share-based Compensation - Stock Options and Restricted Stock Activity (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock Options
Options Outstanding
Balance at beginning of period (in shares)	115,980	313,480
Exercised (in shares)	0		0
Lapsed or canceled (in shares)	0		(197,500)
Balance at end of period (in shares)	115,980	115,980	313,480
Options exercisable at end of period (in shares)	115,980	115,980
Weighted Average Exercise Price
Balance at beginning of year (in dollars per share)	$ 103.52	$ 97.59
Exercised (in dollars per share)	0		$ 0
Lapsed or canceled (in dollars per share)	0		84.14
Balance at end of period (in dollars per share)	103.52	103.52	$ 97.59
Options exercisable at end of period (in dollars per share)	$ 103.52	$ 103.52
Restricted Stock Awards
Summary of restricted stock
Balance at beginning of year (in shares)	4,089,174	3,758,174
Granted (in shares)	3,234		337,350
Canceled (in shares)	(7,450)		(6,350)
Balance at end of period (in shares)	4,084,958	4,089,174	3,758,174
Vested during the period (in shares)	134,620		147,915
Compensation expense	$ 2,625,319		$ 7,766,055
Total fair value of shares granted during the period	$ 151,901		$ 15,789,540

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning balance	$ 3,855,925
Ending balance	3,803,648
Deferred net losses from terminated hedges	(300)	$ (400)
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning balance	17,477
Other comprehensive income before reclassifications	35,451
Amounts reclassified from accumulated other comprehensive income	(12,777)
Ending balance	40,151
Net unrealized gain (loss) on derivative instruments
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning balance	25,352
Other comprehensive income before reclassifications	29,023
Amounts reclassified from accumulated other comprehensive income	(9,095)
Ending balance	45,280
Net unrealized (loss) gain on marketable securities
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning balance	(1,791)
Other comprehensive income before reclassifications	1,019
Amounts reclassified from accumulated other comprehensive income	0
Ending balance	(772)
Joint venture
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning balance	5,036,237
Ending balance	5,493,974
Joint venture | Net unrealized gain (loss) on derivative instruments
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning balance	(6,084)
Other comprehensive income before reclassifications	5,409
Amounts reclassified from accumulated other comprehensive income	(3,682)
Ending balance	$ (4,357)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Fair Value of Financial Instruments
Marketable securities available-for-sale	$ 10,673	$ 9,591
Interest rate cap and swap agreements (included in Other assets)	51,388	33,456
Interest rate cap and swap agreements (included in Other liabilities)	7,754	17,108
Investment fair value adjustment		17,000
Debt and preferred equity investments	$ 352,347	346,745
10 East 53rd Street
Fair Value of Financial Instruments
Ownership Interest Sold	45%
Investment fair value adjustment	$ 55,700
Variable Rate Debt
Fair Value of Financial Instruments
Estimated fair value of debt and preferred equity investments, low end of range	110,500
Estimated fair value of debt and preferred equity investments, high end of range	109,400
Carrying Value
Fair Value of Financial Instruments
Debt and preferred equity investments	352,347	346,745
Fixed rate debt	3,040,885	3,237,386
Variable rate debt	760,493	270,000
Total	3,801,378	3,507,386
Fair Value
Fair Value of Financial Instruments
Total	3,732,967	3,453,125
Estimated fair value of debt and preferred equity investments, low end of range	300,000	300,000
Level 1
Fair Value of Financial Instruments
Marketable securities available-for-sale	0	0
Interest rate cap and swap agreements (included in Other assets)	0	0
Interest rate cap and swap agreements (included in Other liabilities)	0	0
Level 2
Fair Value of Financial Instruments
Marketable securities available-for-sale	10,673	9,591
Interest rate cap and swap agreements (included in Other assets)	51,388	33,456
Interest rate cap and swap agreements (included in Other liabilities)	7,754	17,108
Level 3
Fair Value of Financial Instruments
Marketable securities available-for-sale	0	0
Interest rate cap and swap agreements (included in Other assets)	0	0
Interest rate cap and swap agreements (included in Other liabilities)	0	0
Level 3 | Fair Value
Fair Value of Financial Instruments
Fixed rate debt	2,973,363	3,184,338
Variable rate debt	$ 759,604	$ 268,787

Financial Instruments_ Deriva_3

Financial Instruments: Derivatives and Hedging - Schedule of Notional and Fair Value of Derivative Financial Instruments and Foreign Currency Hedges (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financial Instruments: Derivatives and Hedging
Fair Value	$ 51,388	$ 33,456
Interest Rate Contract
Financial Instruments: Derivatives and Hedging
Fair Value	43,634
Interest Rate Contract | Joint venture
Financial Instruments: Derivatives and Hedging
Fair Value	33,786
Interest Rate Cap Expiring June 2024
Financial Instruments: Derivatives and Hedging
Notional Value	$ 370,000
Strike Rate	3.25%
Fair Value	$ 1,565
Interest Rate Cap Expiring June 2024 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 505,412
Strike Rate	3%
Fair Value	$ 2,490
Interest Rate Cap Expiring in June 2024, 2
Financial Instruments: Derivatives and Hedging
Notional Value	$ 370,000
Strike Rate	3.25%
Fair Value	$ (1,562)
Interest Rate Cap Expiring in February 2025
Financial Instruments: Derivatives and Hedging
Notional Value	$ 220,000
Strike Rate	4%
Fair Value	$ 1,789
Interest Rate Swap Expiring January 2026
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000
Strike Rate	2.621%
Fair Value	$ 4,915
Interest Rate Swap Expiring January 2026, 2
Financial Instruments: Derivatives and Hedging
Notional Value	$ 200,000
Strike Rate	2.662%
Fair Value	$ 6,417
Interest Rate Swap Expiring in February 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 100,000
Strike Rate	2.903%
Fair Value	$ 3,528
Interest Rate Swap Expiring in February 2027, 2
Financial Instruments: Derivatives and Hedging
Notional Value	$ 100,000
Strike Rate	2.733%
Fair Value	$ 3,983
Interest Rate Swap Expiring in February 2027, 3
Financial Instruments: Derivatives and Hedging
Notional Value	$ 50,000
Strike Rate	2.463%
Fair Value	$ 2,354
Interest Rate Swap Expiring in February 2027, 4
Financial Instruments: Derivatives and Hedging
Notional Value	$ 200,000
Strike Rate	2.591%
Fair Value	$ 8,730
Interest Rate Swap Expiring in May 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 300,000
Strike Rate	2.866%
Fair Value	$ 11,314
Interest Rate Swap Expiring in May 2027, 2
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000
Strike Rate	3.524%
Fair Value	$ 2,794
Interest Rate Swap Expiring in June 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 370,000
Strike Rate	3.888%
Fair Value	$ 2,879
Interest Rate Swap Expiring in November 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 300,000
Strike Rate	4.487%
Fair Value	$ (5,113)
Interest Rate Swap Expiring in January 2028
Financial Instruments: Derivatives and Hedging
Notional Value	$ 100,000
Strike Rate	3.756%
Fair Value	$ 1,120
Interest Rate Swap Expiring in February 2025
Financial Instruments: Derivatives and Hedging
Notional Value	$ 204,963
Strike Rate	3.915%
Fair Value	$ (1,079)
Interest Rate Cap Expiring May 2024 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 501,650
Strike Rate	0.49%
Fair Value	$ 2,560
Interest Rate Cap Expiring May 2024, 2 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 501,650
Strike Rate	0.49%
Fair Value	$ 2,560
Interest Rate Cap Expiring August 2024 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 273,616
Strike Rate	4%
Fair Value	$ 1,212
Interest Rate Cap Expiring September 2024 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 514,897
Strike Rate	3.50%
Fair Value	$ 4,118
Interest Rate Cap Expiring November 2024 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 278,161
Strike Rate	4%
Fair Value	$ 1,624
Interest Rate Cap Expiring November 2024, 2 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 278,161
Strike Rate	4%
Fair Value	$ 1,624
Interest Rate Swap Expiring February 2026 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 250,000
Strike Rate	3.608%
Fair Value	$ 4,070
Interest Rate Swap Expiring February 2026, 2 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 250,000
Strike Rate	3.608%
Fair Value	$ 4,069
Interest Rate Swap Expiring February 2026, 3 | Joint venture
Financial Instruments: Derivatives and Hedging
Notional Value	$ 177,000
Strike Rate	1.555%
Fair Value	$ 9,459

Financial Instruments_ Deriva_4

Financial Instruments: Derivatives and Hedging (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Financial Instruments: Derivatives and Hedging
Fair value of derivatives in a net liability position	$ (8.1)
Aggregate termination value	8.5
Estimated current balance held in accumulated other comprehensive loss to be reclassified into earnings within the next 12 months	(32.8)
Interest Expense
Financial Instruments: Derivatives and Hedging
Loss from changes in fair value	0.1	$ 0.1
Income Loss From Equity Method Investments
Financial Instruments: Derivatives and Hedging
Estimated current balance held in accumulated other comprehensive loss to be reclassified into earnings within the next 12 months	(7.3)
Interest Rate Cap
Financial Instruments: Derivatives and Hedging
Loss from changes in fair value	$ 5.2	$ 0.2

Financial Instruments_ Deriva_5

Financial Instruments: Derivatives and Hedging - Schedule of Effect of Derivative Financial Instruments on Consolidated Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Financial Instruments: Derivatives and Hedging
Amount of Gain Recognized in Other Comprehensive (Loss) Income	$ 36,861	$ (19,408)
Amount of Gain Reclassified from Accumulated Other Comprehensive Income into Income	13,647	11,651
Joint venture
Financial Instruments: Derivatives and Hedging
Amount of Gain Recognized in Other Comprehensive (Loss) Income	5,705	(1,495)
Amount of Gain Reclassified from Accumulated Other Comprehensive Income into Income	3,884	2,628
Interest Rate Contract
Financial Instruments: Derivatives and Hedging
Amount of Gain Recognized in Other Comprehensive (Loss) Income	31,156	(17,913)
Amount of Gain Reclassified from Accumulated Other Comprehensive Income into Income	$ 9,763	$ 9,023

Lease Income - Schedule of Leas

Lease Income - Schedule of Lease Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases [Abstract]
Fixed lease payments	$ 128,252	$ 166,353
Variable lease payments	13,301	20,450
Total lease payments	141,553	186,803
Amortization of acquired above and below-market leases	(49)	8,239
Total rental revenue	141,504	195,042
Sublease Income	48,400	48,900
Interest income	$ 1,120	$ 1,106

Segment Information - Additiona

Segment Information - Additional Information (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment information
Number of reportable segments | segment		3
Total revenues		$ 187,882	$ 245,764
Net income (loss)		18,389	(38,357)
Total assets	[1]	9,764,292		$ 9,531,181
Marketing, general and administrative		21,313	23,285
Operating Segments | Real Estate Segment
Segment information
Total revenues		154,875	216,936
Net income (loss)		12,727	(42,883)
Total assets		8,946,952		8,716,738
Operating Segments | SUMMIT Segment
Segment information
Total revenues		25,604	19,771
Net income (loss)		4,453	(2,418)
Total assets		465,787		464,799
Operating Segments | Debt and Preferred Equity Segment
Segment information
Total revenues		7,403	9,057
Net income (loss)		1,209	$ 6,944
Total assets		$ 351,553		$ 349,644
[1] (1) The Company's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $120.4 million and $41.2 million of land, $81.3 million and $40.5 million of building and improvements, $— million and $— million of building and leasehold improvements, $— million and $— million of right of use assets, $5.7 million and $5.4 million of accumulated depreciation, $785.1 million and $676.9 million of other assets included in other line items, $254.3 million and $50.0 million of real estate debt, net, $2.7 million and $0.9 million of accrued interest payable, $— million and $— million of lease liabilities, and $332.5 million and $306.5 million of other liabilities included in other line items as of March 31, 2024 and December 31, 2023, respectively.