Loan Securitization/Sale Activities - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
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)	$ 1,000,000
Infrastructure Lending Segment
Loan Transfer Activities
Net gains (losses) on the sale of loan qualifying for sales treatment				300,000
Loans held-for-sale face amount			2,500,000	38,700,000
Proceeds			$ 2,500,000	$ 38,400,000