Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2024	Apr. 16, 2025	Jun. 30, 2024
Document Information [Line Items]
Document Type	10-K/A
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction Flag	false
Entity Shell Company	false
Entity Public Float			$ 3.3
Entity Common Stock, Shares Outstanding		71,016,826
Amendment Description	On February 18, 2025, we filed our Annual Report on Form 10-K for the year ended December 31, 2024 (the "Original Form 10-K") with the Securities and Exchange Commission (the "SEC"). We are filing this Amendment No. 1 on Form 10-K/A ("Amendment No. 1") solely to amend Part II, Item 8, "Report of Independent Registered Public Accounting Firm" of Ernst & Young LLP included in the Original Form 10-K, which inadvertently included an incorrect reference regarding responsibility for the audit of a change in accounting principle.In accordance with Rule 12b-15 ("Rule 12b-15") under the Securities Exchange Act of 1934, as amended, we have included the entire text of Part II, Item 8 "Financial Statements and Supplementary Data" and Part II, Item 15 "Exhibits, Financial Statements and Schedules" in this Amendment No. 1. In addition, we are including in this Amendment No. 1 new certifications of its Chief Executive Officer and Chief Financial Officer, as required by Rule 12b-15.Except as expressly set forth above, this Amendment No. 1 speaks as of the filing date of the Original Form 10-K, and does not reflect events that may have occurred subsequent to that date, nor does it modify or update in any way disclosure made in the Original Form 10-K, including any of the financial information disclosed in Parts II and IV of the Original Form 10-K.
Entity Central Index Key	0001040971
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Amendment Flag	true
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]
Current Fiscal Year End Date	--12-31
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 Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
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		301,668
Entity Central Index Key	0001492869
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Amendment Flag	true