Related Party Transactions - Acquisitions and Commitments (Details) $ in Thousands	1 Months Ended			3 Months Ended			9 Months Ended
	Apr. 30, 2024 USD ($)	Jan. 31, 2024 USD ($) lease	Feb. 28, 2022 USD ($) director shares	Sep. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) director	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Related Party Transaction [Line Items]
Write-off of investment in preferred equity							$ 1,945
Interest income from sales-type leases				$ 72,429		$ 67,120	212,735	$ 195,573
Ground Lease acquisition purchase price							103,303	$ 137,490
Future funding obligation, amount				35,000			35,000
Land and Related Ground Lease
Related Party Transaction [Line Items]
Future funding obligation, amount				51,800			51,800
Leasehold improvement allowance, funded amount				51,800			51,800
Ground Lease Plus Fund
Related Party Transaction [Line Items]
Number of Ground Leases acquired \| lease		1
Ground Lease acquisition purchase price		$ 38,300
Caret Units
Related Party Transaction [Line Items]
Number of former independent directors affiliated with an existing shareholder investing in redeemable noncontrolling interest \| director			1
Number of units sold \| shares			108,571
Number of shares to be sold under purchase commitment related to merger \| shares			28,571
Expected proceeds from sale of shares under purchase commitment			$ 5,000
Period in which the entity is obligated to provide a public market listing			2 years
Proceeds from stock transaction			$ 19,000
Related party \| Ground Lease Plus Fund \| Land and Related Ground Lease
Related Party Transaction [Line Items]
Purchase price per agreement for acquisition of land and related Ground Lease, subject to certain conditions being met				$ 42,000			$ 42,000
Multiple required by seller that may trigger payment of additional consideration				1.25			1.25
Percentage of required seller return on investment that may trigger payment of additional consideration							9.00%
Related party \| Ground Lease Plus Fund \| Land and Related Ground Lease \| Maximum
Related Party Transaction [Line Items]
Real Estate, Leasehold Improvement Allowance				$ 83,000			$ 83,000
iStar Inc. \| Land and Related Ground Lease
Related Party Transaction [Line Items]
Number of former independent directors affiliated with an existing shareholder participating in or related to a particular project or transaction \| director							1
Preferred equity investment
Related Party Transaction [Line Items]
Funded amount of discretionary commitment to fund preferred equity in entity owning leasehold interest in Ground Lease					$ 1,500
Costs incurred to create entity formed to own leasehold interest in Ground Lease	$ 400
Preferred equity investment \| Maximum
Related Party Transaction [Line Items]
Discretionary commitment to fund preferred equity in entity owning leasehold interest in Ground Lease	$ 9,000
Preferred equity investment \| Other expense
Related Party Transaction [Line Items]
Write-off of investment in preferred equity					$ 1,900
Preferred equity investment \| Land and Related Ground Lease
Related Party Transaction [Line Items]
Interest income from sales-type leases							$ 5,200
Deferred expenses and other assets \| Preferred equity investment
Related Party Transaction [Line Items]
Preferred equity investment									$ 1,900
Safehold, Inc. (Old SAFE) \| Caret Units
Related Party Transaction [Line Items]
Number of former independent directors affiliated with an existing shareholder investing in redeemable noncontrolling interest \| director			1
Number of units sold \| shares			108,571
Percentage of authorized shares sold			1.08%
Number of shares to be sold under purchase commitment related to merger \| shares			28,571
Percentage of authorized shares under commitment to be purchased			0.29%
Expected proceeds from sale of shares under purchase commitment			$ 5,000
Period in which the entity is obligated to provide a public market listing			2 years

Safehold Inc. 10-Q