Loans - Changes in the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in the Allowance for Loan Losses
Beginning of period balance				$ 27,848				$ 19,658	$ 27,848	$ 19,658	$ 19,089
Charge-offs									(6,623)	(2,026)	(2,239)
Recoveries									1,214	2,795	2,709
Net (charge-offs) recoveries									(5,409)	769	470
Provision for loan losses	$ 3,223	$ (576)	$ (740)	(1,061)	$ 142	$ (425)	$ 7,198	506	846	7,421	99
End of period balance	23,285				27,848				23,285	27,848	19,658
Commercial
Changes in the Allowance for Loan Losses
Beginning of period balance				17,061				10,608	17,061	10,608	10,656
Charge-offs									(6,609)	(2,002)	(2,239)
Recoveries									1,045	2,645	1,585
Net (charge-offs) recoveries									(5,564)	643	(654)
Provision for loan losses									(1,044)	5,810	606
End of period balance	10,453				17,061				10,453	17,061	10,608
Real estate
Changes in the Allowance for Loan Losses
Beginning of period balance				10,671				8,950	10,671	8,950	8,327
Recoveries									169	150	1,124
Net (charge-offs) recoveries									169	150	1,124
Provision for loan losses									1,910	1,571	(501)
End of period balance	12,750				10,671				12,750	10,671	8,950
Consumer
Changes in the Allowance for Loan Losses
Beginning of period balance				$ 116				$ 100	116	100	106
Charge-offs									(14)	(24)
Net (charge-offs) recoveries									(14)	(24)
Provision for loan losses									(20)	40	(6)
End of period balance	$ 82				$ 116				$ 82	$ 116	$ 100