Allowance for Loan Losses - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	$ 19,893	$ 18,183	$ 19,697	$ 18,153
Charge-Offs	(207)	(135)	(486)	(869)
Recoveries	75	137	150	198
Provision (benefit)	300	200	700	903
Balance, end of period	19,893	18,183	19,697	18,153	$ 20,061	$ 18,385
Balance, end of period: Individually evaluated for impairment					394	227
Balance, end of period: collectively evaluated for impairment					19,667	18,158
Commercial
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	5,701	5,749	5,535	5,906
Charge-Offs	(202)	(135)	(464)	(868)
Recoveries	71	135	144	193
Provision (benefit)	252	118	607	636
Balance, end of period	5,701	5,749	5,535	5,906	5,822	5,867
Balance, end of period: Individually evaluated for impairment					394	0
Balance, end of period: collectively evaluated for impairment					5,428	5,867
Real estate construction one-to-four family
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	549	760	550	854
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	(28)	132	(29)	38
Balance, end of period	549	760	550	854	521	892
Balance, end of period: Individually evaluated for impairment					0	204
Balance, end of period: collectively evaluated for impairment					521	688
Real estate construction other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	1,383	1,621	1,465	1,439
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	134	(524)	52	(342)
Balance, end of period	1,383	1,621	1,465	1,439	1,517	1,097
Balance, end of period: Individually evaluated for impairment					0	0
Balance, end of period: collectively evaluated for impairment					1,517	1,097
Real estate term owner occupied
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	2,372	1,739	2,358	1,657
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	(18)	546	(4)	628
Balance, end of period	2,372	1,739	2,358	1,657	2,354	2,285
Balance, end of period: Individually evaluated for impairment					0	0
Balance, end of period: collectively evaluated for impairment					2,354	2,285
Real estate term non-owner occupied
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	7,207	5,498	6,853	5,515
Charge-Offs	(5)	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	(127)	(200)	222	(217)
Balance, end of period	7,207	5,498	6,853	5,515	7,075	5,298
Balance, end of period: Individually evaluated for impairment					0	0
Balance, end of period: collectively evaluated for impairment					7,075	5,298
Real estate term other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	774	638	819	628
Charge-Offs	0	0	(5)	0
Recoveries	0	0	0	0
Provision (benefit)	0	32	(40)	42
Balance, end of period	774	638	819	628	774	670
Balance, end of period: Individually evaluated for impairment					0	0
Balance, end of period: collectively evaluated for impairment					774	670
Consumer secured by 1st deeds of trust
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	311	264	313	264
Charge-Offs	0	0	0	0
Recoveries	2	0	2	0
Provision (benefit)	14	82	12	82
Balance, end of period	311	264	313	264	327	346
Balance, end of period: Individually evaluated for impairment					0	23
Balance, end of period: collectively evaluated for impairment					327	323
Consumer other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	391	396	408	397
Charge-Offs	0	0	(17)	(1)
Recoveries	2	2	4	5
Provision (benefit)	(31)	22	(33)	19
Balance, end of period	391	396	408	397	362	420
Balance, end of period: Individually evaluated for impairment					0	0
Balance, end of period: collectively evaluated for impairment					362	420
Unallocated
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	1,205	1,518	1,396	1,493
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	104	(8)	(87)	17
Balance, end of period	$ 1,205	$ 1,518	$ 1,396	$ 1,493	1,309	1,510
Balance, end of period: Individually evaluated for impairment					0	0
Balance, end of period: collectively evaluated for impairment					$ 1,309	$ 1,510