Noninterest Income - Lending Related Fees (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lending related fees	$ 13,562	$ 11,707	$ 37,851	$ 36,857
Unused commitment fees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lending related fees	9,872	8,339	26,602	25,060
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lending related fees	$ 3,690	$ 3,368	$ 11,249	$ 11,797