Loans and Allowance for Loan Losses - Impaired non acquired and acquired loans - FASB 310-20 - (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	$ 13,067	$ 17,922	$ 13,067	$ 17,922	$ 14,464
Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	63,601	37,246	63,601	37,246	35,079
Recorded Investment With No Allowance	7,810	10,019	7,810	10,019	7,736
Gross Recorded Investment With Allowance	41,310	14,304	41,310	14,304	13,475
Total Recorded Investment	49,120	24,323	49,120	24,323	21,211
Related Allowance	2,300	1,507	2,300	1,507	1,337
Average Investment In Impaired Loans	38,221	28,758	35,165	27,270
Interest Income Recognized	478	58	719	339
Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	5,134	4,438	5,134	4,438	4,728
Commercial non-owner occupied real estate | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	2,637	1,608	2,637	1,608	1,250
Commercial non-owner occupied real estate | Non acquired non-accrual loans | Construction and land development
Loans and Allowance for Loan Losses
Nonaccrual loans	62	1,080	62	1,080	672
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	2,575	528	2,575	528	578
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	34,757	8,286	34,757	8,286	7,394
Recorded Investment With No Allowance	1,289	798	1,289	798	1,074
Gross Recorded Investment With Allowance	28,748	3,295	28,748	3,295	1,959
Total Recorded Investment	30,037	4,093	30,037	4,093	3,033
Related Allowance	1,310	752	1,310	752	348
Average Investment In Impaired Loans	19,662	5,182
Interest Income Recognized	267	8
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	2,376	1,669	2,376	1,669	2,417
Recorded Investment With No Allowance	212	337	212	337	223
Gross Recorded Investment With Allowance	542	882	542	882	583
Total Recorded Investment	754	1,219	754	1,219	806
Related Allowance	146	202	146	202	170
Average Investment In Impaired Loans	764	1,177
Interest Income Recognized	6	11
Commercial non-owner occupied real estate | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	226	99	226	99	232
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	226	99	226	99	232
Commercial owner occupied real estate loan | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	2,641	2,242	2,641	2,242	2,189
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	9,882	10,784	9,882	10,784	10,118
Recorded Investment With No Allowance	4,075	4,988	4,075	4,988	3,976
Gross Recorded Investment With Allowance	1,979	1,984	1,979	1,984	2,269
Total Recorded Investment	6,054	6,972	6,054	6,972	6,245
Related Allowance	62	67	62	67	67
Average Investment In Impaired Loans	6,153	7,337
Interest Income Recognized	69	6
Commercial owner occupied real estate loan | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	44	306	44	306	61
Consumer real estate | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	4,166	9,091	4,166	9,091	7,340
Consumer real estate | Non acquired non-accrual loans | Home equity loans
Loans and Allowance for Loan Losses
Nonaccrual loans	10	2,386	10	2,386	1,629
Consumer real estate | Non acquired non-accrual loans | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Nonaccrual loans	4,156	6,705	4,156	6,705	5,711
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	3,311	3,024	3,311	3,024	2,165
Recorded Investment With No Allowance	688	812	688	812	244
Gross Recorded Investment With Allowance	1,938	1,365	1,938	1,365	1,430
Total Recorded Investment	2,626	2,177	2,626	2,177	1,674
Related Allowance	119	38	119	38	40
Average Investment In Impaired Loans	2,529	2,680
Interest Income Recognized	26	4
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	6,093	5,420	6,093	5,420	7,090
Recorded Investment With No Allowance	1,451	2,333	1,451	2,333	2,120
Gross Recorded Investment With Allowance	3,124	1,634	3,124	1,634	3,553
Total Recorded Investment	4,575	3,967	4,575	3,967	5,673
Related Allowance	57	55	57	55	80
Average Investment In Impaired Loans	4,644	5,805
Interest Income Recognized	35
Consumer real estate | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	3,442	2,663	3,442	2,663	3,048
Consumer real estate | Acquired non-credit impaired non-accrual including restructured loans | Home equity loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,515	1,607	1,515	1,607	1,643
Consumer real estate | Acquired non-credit impaired non-accrual including restructured loans | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,927	1,056	1,927	1,056	1,405
Commercial and industrial | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	596	360	596	360	420
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	2,244	1,891	2,244	1,891	2,335
Recorded Investment With No Allowance		259		259
Gross Recorded Investment With Allowance	1,198	508	1,198	508	1,263
Total Recorded Investment	1,198	767	1,198	767	1,263
Related Allowance	362	14	362	14	386
Average Investment In Impaired Loans	1,234	822	1,230	1,127
Interest Income Recognized	4	6	22	85
Commercial and industrial | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	57	1	57	1	1
Other income producing property | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,162	1,007	1,162	1,007	356
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	4,382	5,838	4,382	5,838	3,166
Recorded Investment With No Allowance	95	492	95	492	99
Gross Recorded Investment With Allowance	3,546	4,508	3,546	4,508	2,273
Total Recorded Investment	3,641	5,000	3,641	5,000	2,372
Related Allowance	238	375	238	375	242
Average Investment In Impaired Loans	3,024	5,197	3,007	4,946
Interest Income Recognized	68	23	103	30
Other income producing property | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	159	153	159	153	145
Consumer | Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	898	763	898	763	930
Consumer | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Unpaid Contractual Principal Balance	556	334	556	334	394
Gross Recorded Investment With Allowance	235	128	235	128	145
Total Recorded Investment	235	128	235	128	145
Related Allowance	6	4	6	4	4
Average Investment In Impaired Loans	211	135	189	115
Interest Income Recognized	3		3	1
Consumer | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Home equity loans
Loans and Allowance for Loan Losses
Average Investment In Impaired Loans			2,150	1,243
Interest Income Recognized			46	12
Consumer | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Average Investment In Impaired Loans			5,124	5,758
Interest Income Recognized			74	46
Consumer | Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,206	1,216	1,206	1,216	1,241
Commercial | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Average Investment In Impaired Loans			780	1,335
Interest Income Recognized			12	26
Commercial | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Construction and land development
Loans and Allowance for Loan Losses
Average Investment In Impaired Loans			16,535	5,187
Interest Income Recognized			314	57
Commercial | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20 | Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Average Investment In Impaired Loans			6,150	7,348
Interest Income Recognized			$ 145	80
Other loans | Impaired non-acquired and acquired loans accounted under FASB ASC topic 310-20
Loans and Allowance for Loan Losses
Average Investment In Impaired Loans		423		211
Interest Income Recognized				2
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	$ 967	$ 2,851	$ 967	$ 2,851	$ 1,979