Debt and Preferred Equity Investments - Schedule of Debt Investments with an Aggregate Weighted Average Current Yield (Details) - USD ($)	9 Months Ended
	Sep. 30, 2025	Dec. 31, 2024	Dec. 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgage loans on real estate, interest rate	5.13%
Debt Investments Held [Abstract]
Carrying value, fixed rate	$ 171,412,000	$ 303,726,000
Debt and preferred equity investments	171,412,000	303,726,000
Allowance for loan loss	(454,000)	(13,520,000)	$ (13,520,000)
Debt Investments in Mortgage Loans
Debt Investments Held [Abstract]
Future funding obligations	2,999,000
Senior financing	713,528,000
Debt and preferred equity investments	171,412,000	167,006,000
Allowance for loan loss	(454,000)	(13,520,000)
Total fixed rate
Debt Investments Held [Abstract]
Future funding obligations	0
Senior financing	180,000,000
Carrying value, fixed rate	40,786,000	63,366,000
Total fixed rate | Mezzanine Loan Due June 2024
Debt Investments Held [Abstract]
Future funding obligations	0
Senior financing	0
Carrying value, fixed rate	0	13,366,000
Total fixed rate | Mezzanine Loan Due January 2025 -1
Debt Investments Held [Abstract]
Future funding obligations	0
Senior financing	95,000,000
Carrying value, fixed rate	20,786,000	30,000,000
Total fixed rate | Mezzanine Loan Due December 2029
Debt Investments Held [Abstract]
Future funding obligations	0
Senior financing	85,000,000
Carrying value, fixed rate	20,000,000	20,000,000
Total floating rate
Debt Investments Held [Abstract]
Future funding obligations	2,999,000
Senior financing	533,528,000
Debt and preferred equity investments	131,080,000	117,160,000
Total floating rate | Mezzanine Loan Due July 2025
Debt Investments Held [Abstract]
Future funding obligations	0
Senior financing	54,000,000
Debt and preferred equity investments	9,268,000	8,991,000
Loan interest income	0
Total floating rate | Mezzanine Loan Due December 2025
Debt Investments Held [Abstract]
Future funding obligations	0
Senior financing	283,000,000
Debt and preferred equity investments	53,687,000	53,687,000
Loan interest income	0
Total floating rate | Mezzanine Loan Due January 2026
Debt Investments Held [Abstract]
Future funding obligations	2,999,000
Senior financing	196,528,000
Debt and preferred equity investments	$ 68,125,000	$ 54,482,000