Loans and Preferred Equity Held for Investment, net - Nonaccrual and Past Due Loans (Details) $ in Thousands	Sep. 30, 2026 USD ($)	Sep. 30, 2026 loan	Sep. 30, 2026 property	Jun. 30, 2026 USD ($)	Dec. 31, 2025 USD ($) loan
Financing Receivable, Past Due [Line Items]
Carrying Value	$ 3,082,324				$ 2,678,315
Denver, Colorado
Financing Receivable, Past Due [Line Items]
Number of loans on nonaccrual status \| loan					1
Loan carrying value, nonaccrual				$ 64,000	$ 22,000
Denver, Colorado \| Multifamily
Financing Receivable, Past Due [Line Items]
Number of loans on nonaccrual status		2	2
Denver, Colorado \| Office
Financing Receivable, Past Due [Line Items]
Number of loans on nonaccrual status \| loan		1
Baltimore, Maryland
Financing Receivable, Past Due [Line Items]
Number of loans on nonaccrual status \| loan		1			1
Loan carrying value, nonaccrual	15,100				$ 14,700
Commercial mortgage
Financing Receivable, Past Due [Line Items]
Carrying Value	3,082,324				2,678,315
Commercial mortgage \| Current or Less Than 30 Days Past Due
Financing Receivable, Past Due [Line Items]
Carrying Value	3,003,248				2,641,623
Commercial mortgage \| 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Carrying Value	63,971				0
Commercial mortgage \| 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Carrying Value	0				0
Commercial mortgage \| 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Carrying Value	$ 15,105				$ 36,692