Allowance for Loan Losses - Recorded Investment Segregated By Amounts Individually Or Collectively In Allowance For Loan Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	$ 993,228	$ 979,449
Balance, end of period: Individually evaluated for impairment	39,722	38,656
Balance, end of period: Collectively evaluated for impairment	953,506	940,793
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	315,512	278,178
Balance, end of period: Individually evaluated for impairment	29,442	18,657
Balance, end of period: Collectively evaluated for impairment	286,070	259,521
Real estate construction one-to-four family
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	27,543	26,061
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: Collectively evaluated for impairment	27,543	26,061
Real estate construction other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	83,884	72,159
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: Collectively evaluated for impairment	83,884	72,159
Real estate term owner occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	135,053	152,178
Balance, end of period: Individually evaluated for impairment	7,300	16,946
Balance, end of period: Collectively evaluated for impairment	127,753	135,232
Real estate term non-owner occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	344,968	356,601
Balance, end of period: Individually evaluated for impairment	902	1,084
Balance, end of period: Collectively evaluated for impairment	344,066	355,517
Real estate term other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	41,326	45,402
Balance, end of period: Individually evaluated for impairment	1,214	1,302
Balance, end of period: Collectively evaluated for impairment	40,112	44,100
Consumer secured by 1st deeds of trust
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	23,333	23,589
Balance, end of period: Individually evaluated for impairment	864	615
Balance, end of period: Collectively evaluated for impairment	22,469	22,974
Consumer other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total financing receivables	21,609	25,281
Balance, end of period: Individually evaluated for impairment	0	52
Balance, end of period: Collectively evaluated for impairment	$ 21,609	$ 25,229