Leases and Commitments - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Operating lease right-of-use assets	$ 2,792
Lease liabilities	2,824	$ 0
Commitments to Extend Credit
Other Commitments [Line Items]
Reserve for commitments	272,800	289,900
Commitments expire within one year	119,200	181,900
Standby Letters of Credit
Other Commitments [Line Items]
Reserve for commitments	$ 4,800	$ 5,700
Minimum
Other Commitments [Line Items]
Operating lease, remaining contract term	1 year
Operating Lease renewal term	1 year
Maximum
Other Commitments [Line Items]
Operating lease, remaining contract term	10 years
Operating Lease renewal term	5 years