Loans and Allowance for Loan Losses - Impaired non acquired and acquired loans - FASB 310-20 - (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Loans and Allowance for Loan Losses
Nonaccrual loans		$ 4,130		$ 4,130
Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	$ 14,884	23,715	$ 14,884	23,715	$ 18,447
Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	35,011	46,388	35,011	46,388	43,010
Recorded Investment With No Allowance	7,755	14,622	7,755	14,622	9,447
Gross Recorded Investment With Allowance	13,432	19,857	13,432	19,857	20,771
Total Recorded Investment	21,187	34,479	21,187	34,479	30,218
Related Allowance	1,379	1,456	1,379	1,456	1,607
Average Investment In Impaired Loans	22,755	32,797	25,702	30,783
Interest Income Recognized	312	431	653	830
Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	4,633		4,633		3,764
Commercial non-owner occupied real estate
Loans and Allowance for Loan Losses
Nonaccrual loans		134		134
Commercial non-owner occupied real estate | Construction and land development
Loans and Allowance for Loan Losses
Nonaccrual loans		39		39
Commercial non-owner occupied real estate | Other commercial non-owner occupied real estate
Loans and Allowance for Loan Losses
Nonaccrual loans		95		95
Commercial non-owner occupied real estate | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,757	2,408	1,757	2,408	1,274
Commercial non-owner occupied real estate | Non acquired non-accrual loans | Construction and land development
Loans and Allowance for Loan Losses
Nonaccrual loans	1,156	1,291	1,156	1,291	1,090
Commercial non-owner occupied real estate | Non acquired non-accrual loans | Other commercial non-owner occupied real estate
Loans and Allowance for Loan Losses
Nonaccrual loans	601	1,117	601	1,117	184
Commercial non-owner occupied real estate | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Construction and land development
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	7,744	8,321	7,744	8,321	9,931
Recorded Investment With No Allowance	1,331	1,128	1,331	1,128	1,004
Gross Recorded Investment With Allowance	2,100	4,599	2,100	4,599	5,276
Total Recorded Investment	3,431	5,727	3,431	5,727	6,280
Related Allowance	359	585	359	585	615
Average Investment In Impaired Loans	3,762	5,418	4,856	5,290
Interest Income Recognized	31	116	88	170
Commercial non-owner occupied real estate | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Other commercial non-owner occupied real estate
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	2,372	3,935	2,372	3,935	2,909
Recorded Investment With No Allowance	228	1,644	228	1,644	233
Gross Recorded Investment With Allowance	536	925	536	925	1,219
Total Recorded Investment	764	2,569	764	2,569	1,452
Related Allowance	181	26	181	26	34
Average Investment In Impaired Loans	992	2,590	1,108	3,090
Interest Income Recognized		13	23	38
Commercial non-owner occupied real estate | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	235		235		37
Commercial non-owner occupied real estate | Acquired non-credit impaired non-accrual including restructured loans | Construction and land development
Loans and Allowance for Loan Losses
Nonaccrual loans	235		235		37
Commercial owner occupied real estate loan
Loans and Allowance for Loan Losses
Nonaccrual loans		40		40
Commercial owner occupied real estate loan | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	2,049	4,353	2,049	4,353	3,056
Commercial owner occupied real estate loan | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	10,204	16,195	10,204	16,195	11,516
Recorded Investment With No Allowance	4,301	7,325	4,301	7,325	4,134
Gross Recorded Investment With Allowance	2,051	4,120	2,051	4,120	3,591
Total Recorded Investment	6,352	11,445	6,352	11,445	7,725
Related Allowance	65	248	65	248	101
Average Investment In Impaired Loans	6,662	11,208	7,038	10,303
Interest Income Recognized	150	89	233	255
Commercial owner occupied real estate loan | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	302		302		44
Consumer real estate
Loans and Allowance for Loan Losses
Nonaccrual loans		2,163		2,163
Consumer real estate | Home equity loans
Loans and Allowance for Loan Losses
Nonaccrual loans		1,115		1,115
Consumer real estate | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Nonaccrual loans		1,048		1,048
Consumer real estate | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	6,612	9,576	6,612	9,576	9,535
Consumer real estate | Non acquired non-accrual loans | Home equity loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,564	1,533	1,564	1,533	1,769
Consumer real estate | Non acquired non-accrual loans | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Nonaccrual loans	5,048	8,043	5,048	8,043	7,766
Consumer real estate | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Home equity loans
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	2,054	390	2,054	390	483
Recorded Investment With No Allowance	251	185	251	185	186
Gross Recorded Investment With Allowance	1,348	108	1,348	108	123
Total Recorded Investment	1,599	293	1,599	293	309
Related Allowance	38	3	38	3	3
Average Investment In Impaired Loans	1,888	263	954	162
Interest Income Recognized	13	4	43	7
Consumer real estate | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	4,390	8,969	4,390	8,969	9,001
Recorded Investment With No Allowance	1,284	3,928	1,284	3,928	3,505
Gross Recorded Investment With Allowance	1,843	3,890	1,843	3,890	4,044
Total Recorded Investment	3,127	7,818	3,127	7,818	7,549
Related Allowance	58	121	58	121	138
Average Investment In Impaired Loans	3,547	7,070	5,338	5,392
Interest Income Recognized	31	80	78	133
Consumer real estate | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	2,700		2,700		2,079
Consumer real estate | Acquired non-credit impaired non-accrual including restructured loans | Home equity loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,588		1,588		1,103
Consumer real estate | Acquired non-credit impaired non-accrual including restructured loans | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,112		1,112		976
Commercial and industrial
Loans and Allowance for Loan Losses
Nonaccrual loans		243		243
Commercial and industrial | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	587	466	587	466	515
Commercial and industrial | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	2,738	1,939	2,738	1,939	2,641
Recorded Investment With No Allowance	259	295	259	295	273
Gross Recorded Investment With Allowance	1,194	750	1,194	750	1,214
Total Recorded Investment	1,453	1,045	1,453	1,045	1,487
Related Allowance	385	21	385	21	279
Average Investment In Impaired Loans	1,110	1,028	1,470	976
Interest Income Recognized	16	29	28	47
Commercial and industrial | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1		1		1
Other income producing property
Loans and Allowance for Loan Losses
Nonaccrual loans		382		382
Other income producing property | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	584	740	584	740	746
Other income producing property | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	5,167	5,601	5,167	5,601	5,763
Recorded Investment With No Allowance	101	117	101	117	112
Gross Recorded Investment With Allowance	4,218	4,671	4,218	4,671	4,779
Total Recorded Investment	4,319	4,788	4,319	4,788	4,891
Related Allowance	289	430	289	430	422
Average Investment In Impaired Loans	4,659	4,788	4,605	5,143
Interest Income Recognized	71	95	157	174
Other income producing property | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	149		149		168
Consumer
Loans and Allowance for Loan Losses
Nonaccrual loans		1,168		1,168
Consumer | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	796	556	796	556	659
Consumer | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	342	887	342	887	155
Gross Recorded Investment With Allowance	142	693	142	693	102
Total Recorded Investment	142	693	142	693	102
Related Allowance	4	19	4	19	3
Average Investment In Impaired Loans	135	85	122	80
Interest Income Recognized		1	3	2
Consumer | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,246		1,246		1,435
Other loans | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance					611
Gross Recorded Investment With Allowance					423
Total Recorded Investment					423
Related Allowance					12
Average Investment In Impaired Loans		347	$ 211	347
Interest Income Recognized		4		4
Restructured loans | ASC Topic 31020 Loans
Loans and Allowance for Loan Losses
Number of months generally required to return to accruing status			6 months
Restructured loans | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	$ 2,499	$ 5,616	$ 2,499	$ 5,616	$ 2,662