Loans - Loan Categories Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Schedule of Loans by Loan Classification [Line Items]
Number of Paycheck Protection Loans	2,636	2,636
Gross loans	$ 3,194,723	$ 3,194,723	$ 2,568,562
Commercial
Schedule of Loans by Loan Classification [Line Items]
Participation loans amount	102,500	102,500	104,300
Gross loans	2,835,606	2,835,606	2,212,883
Participations loans sold that are still serviced amount	$ 78,000	$ 78,000	80,200
SBA Paycheck Protection Program
Schedule of Loans by Loan Classification [Line Items]
Loans Receivable, Interest Rate	1.00%	1.00%
Loans and Leases Receivable Term, Minimum		2 years
Loans and Leases Receivable Term, Maximum		5 years
Gross loans	$ 505,557	$ 505,557	0
Loans and Leases Receivable, Deferred Income, Gross	17,000	17,000
Deferred Income, processing fees	15,398	15,398	0
Amortization of Deferred Loan Origination Fees, Net	1,600
Residential mortgages
Schedule of Loans by Loan Classification [Line Items]
Gross loans	261,786	261,786	247,373
Amount of loans serviced for others	$ 15,900	$ 15,900	$ 15,700