Loan Securitization/Sale Activities - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
RMBS
Loan Transfer Activities
Payments to acquire marketable securities	$ 0	$ 0	$ 524,500,000
Redemptions			51,200,000
Commercial and Residential Lending Segment
Loan Transfer Activities
Net gains (losses) on the sale of loan qualifying for sales treatment	0	0	(1,100,000)
Infrastructure Lending Segment
Loan Transfer Activities
Net gains (losses) on the sale of loan qualifying for sales treatment			200,000
Loans held-for-sale face amount	$ 0	$ 26,800,000	16,300,000
Proceeds			$ 15,300,000