Allowance for Loan Losses - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	$ 18,385	$ 17,418	$ 18,153	$ 16,723
Charge-Offs	(22)	(400)	(891)	(588)
Recoveries	464	154	662	335
Provision (benefit)	652	676	1,555	1,378
Balance, end of period	19,479	17,848	19,479	17,848
Balance, end of period: Individually evaluated for impairment	535	513	535	513
Balance, end of period: collectively evaluated for impairment	18,944	17,335	18,944	17,335
Commercial
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	5,867	5,687	5,906	5,643
Charge-Offs	0	(367)	(868)	(474)
Recoveries	450	152	643	310
Provision (benefit)	(278)	308	358	301
Balance, end of period	6,039	5,780	6,039	5,780
Balance, end of period: Individually evaluated for impairment	0	433	0	433
Balance, end of period: collectively evaluated for impairment	6,039	5,347	6,039	5,347
Real estate construction one-to-four family
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	892	689	854	644
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	306	202	344	247
Balance, end of period	1,198	891	1,198	891
Balance, end of period: Individually evaluated for impairment	535	0	535	0
Balance, end of period: collectively evaluated for impairment	663	891	663	891
Real estate construction other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	1,097	1,863	1,439	1,653
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	312	(81)	(30)	129
Balance, end of period	1,409	1,782	1,409	1,782
Balance, end of period: Individually evaluated for impairment	0	0	0	0
Balance, end of period: collectively evaluated for impairment	1,409	1,782	1,409	1,782
Real estate term owner occupied
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	2,285	1,470	1,657	1,580
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	314	54	942	(56)
Balance, end of period	2,599	1,524	2,599	1,524
Balance, end of period: Individually evaluated for impairment	0	0	0	0
Balance, end of period: collectively evaluated for impairment	2,599	1,524	2,599	1,524
Real estate term non-owner occupied
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	5,298	4,888	5,515	4,704
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	103	54	(114)	238
Balance, end of period	5,401	4,942	5,401	4,942
Balance, end of period: Individually evaluated for impairment	0	0	0	0
Balance, end of period: collectively evaluated for impairment	5,401	4,942	5,401	4,942
Real estate term other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	670	671	628	656
Charge-Offs	0	0	0	(81)
Recoveries	0	0	0	17
Provision (benefit)	73	(69)	115	10
Balance, end of period	743	602	743	602
Balance, end of period: Individually evaluated for impairment	0	0	0	0
Balance, end of period: collectively evaluated for impairment	743	602	743	602
Consumer secured by 1st deeds of trust
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	346	265	264	285
Charge-Offs	(22)	(28)	(22)	(28)
Recoveries	0	0	0	0
Provision (benefit)	2	31	84	11
Balance, end of period	326	268	326	268
Balance, end of period: Individually evaluated for impairment	0	0	0	0
Balance, end of period: collectively evaluated for impairment	326	268	326	268
Consumer other
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	420	415	397	410
Charge-Offs	0	(5)	(1)	(5)
Recoveries	14	2	19	8
Provision (benefit)	(28)	64	(9)	63
Balance, end of period	406	476	406	476
Balance, end of period: Individually evaluated for impairment	0	80	0	80
Balance, end of period: collectively evaluated for impairment	406	396	406	396
Unallocated
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	1,510	1,470	1,493	1,148
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Provision (benefit)	(152)	113	(135)	435
Balance, end of period	1,358	1,583	1,358	1,583
Balance, end of period: Individually evaluated for impairment	0	0	0	0
Balance, end of period: collectively evaluated for impairment	$ 1,358	$ 1,583	$ 1,358	$ 1,583