Allowance for Loan Losses - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	$ 19,697	$ 18,153
Charge-Offs	(279)	(734)
Recoveries	75	61
Provision (benefit)	400	703
Balance, end of period	19,893	18,183
Balance, end of period: Individually evaluated for impairment	994	119
Balance, end of period: collectively evaluated for impairment	18,899	18,064
Commercial
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	5,535	5,906
Charge-Offs	(262)	(733)
Recoveries	73	58
Provision (benefit)	355	518
Balance, end of period	5,701	5,749
Balance, end of period: Individually evaluated for impairment	994	119
Balance, end of period: collectively evaluated for impairment	4,707	5,630
Real estate construction one-to-four family
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	550	854
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	(1)	(94)
Balance, end of period	549	760
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	549	760
Real estate construction other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	1,465	1,439
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	(82)	182
Balance, end of period	1,383	1,621
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	1,383	1,621
Real estate term owner occupied
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	2,358	1,657
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	14	82
Balance, end of period	2,372	1,739
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	2,372	1,739
Real estate term non-owner occupied
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	6,853	5,515
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	354	(17)
Balance, end of period	7,207	5,498
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	7,207	5,498
Real estate term other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	819	628
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	(45)	10
Balance, end of period	774	638
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	774	638
Consumer secured by 1st deeds of trust
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	313	264
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	(2)	0
Balance, end of period	311	264
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	311	264
Consumer other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	408	397
Charge-Offs	(17)	(1)
Recoveries	2	3
Provision (benefit)	(2)	(3)
Balance, end of period	391	396
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	391	396
Unallocated
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	1,396	1,493
Charge-Offs	0	0
Recoveries	0	0
Provision (benefit)	(191)	25
Balance, end of period	1,205	1,518
Balance, end of period: Individually evaluated for impairment	0	0
Balance, end of period: collectively evaluated for impairment	$ 1,205	$ 1,518