Loans and Allowance for Loan Losses - Impaired non acquired and acquired loans - FASB 310-20 - (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	$ 12,958	$ 19,047	$ 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	41,242	48,635	35,079
Recorded Investment With No Allowance	7,585	9,331	7,736
Gross Recorded Investment With Allowance	19,738	23,860	13,475
Total Recorded Investment	27,323	33,191	21,211
Related Allowance	1,658	1,699	1,337
Average Investment In Impaired Loans	24,267	31,705
Interest Income Recognized	241	281
Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	4,915	3,951	4,728
Commercial non-owner occupied real estate \| Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	2,273	1,434	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	195	1,297	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	2,078	137	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	13,674	11,414	7,394
Recorded Investment With No Allowance	1,344	988	1,074
Gross Recorded Investment With Allowance	7,942	5,283	1,959
Total Recorded Investment	9,286	6,271	3,033
Related Allowance	459	843	348
Average Investment In Impaired Loans	6,160	6,276
Interest Income Recognized	47	49
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	2,393	2,757	2,417
Recorded Investment With No Allowance	218	349	223
Gross Recorded Investment With Allowance	557	786	583
Total Recorded Investment	775	1,135	806
Related Allowance	158	22	170
Average Investment In Impaired Loans	791	1,293
Interest Income Recognized	6	15
Commercial non-owner occupied real estate \| Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	229	102	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	229	102	232
Commercial owner occupied real estate loan \| Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	2,905	2,452	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	10,082	11,316	10,118
Recorded Investment With No Allowance	4,191	4,004	3,976
Gross Recorded Investment With Allowance	2,060	3,697	2,269
Total Recorded Investment	6,251	7,701	6,245
Related Allowance	60	148	67
Average Investment In Impaired Loans	6,248	7,713
Interest Income Recognized	76	74
Commercial owner occupied real estate loan \| Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	158	219	61
Consumer real estate \| Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	3,913	9,591	7,340
Consumer real estate \| Non acquired non-accrual loans \| Home equity loans
Loans and Allowance for Loan Losses
Nonaccrual loans	11	2,086	1,629
Consumer real estate \| Non acquired non-accrual loans \| Consumer Owner Occupied Loans
Loans and Allowance for Loan Losses
Nonaccrual loans	3,902	7,505	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	2,962	3,835	2,165
Recorded Investment With No Allowance	252	344	244
Gross Recorded Investment With Allowance	2,180	2,838	1,430
Total Recorded Investment	2,432	3,182	1,674
Related Allowance	297	79	40
Average Investment In Impaired Loans	2,053	1,746
Interest Income Recognized	20	26
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	6,084	9,463	7,090
Recorded Investment With No Allowance	1,483	2,891	2,120
Gross Recorded Investment With Allowance	3,229	4,752	3,553
Total Recorded Investment	4,712	7,643	5,673
Related Allowance	68	148	80
Average Investment In Impaired Loans	5,192	7,596
Interest Income Recognized	39	46
Consumer real estate \| Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	3,237	2,131	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	1,784	1,279	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	1,453	852	1,405
Commercial and industrial \| Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	473	610	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	2,419	2,181	2,335
Recorded Investment With No Allowance		259
Gross Recorded Investment With Allowance	1,270	618	1,263
Total Recorded Investment	1,270	877	1,263
Related Allowance	387	17	386
Average Investment In Impaired Loans	1,266	1,182
Interest Income Recognized	18	6
Commercial and industrial \| Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	0	2	1
Other income producing property \| Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,316	1,116	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	3,153	6,270	3,166
Recorded Investment With No Allowance	97	496	99
Gross Recorded Investment With Allowance	2,311	4,898	2,273
Total Recorded Investment	2,408	5,394	2,372
Related Allowance	224	414	242
Average Investment In Impaired Loans	2,390	5,143
Interest Income Recognized	35	62
Other income producing property \| Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	83	157	145
Consumer \| Non acquired non-accrual loans
Loans and Allowance for Loan Losses
Nonaccrual loans	1,029	786	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	475	338	394
Gross Recorded Investment With Allowance	189	142	145
Total Recorded Investment	189	142	145
Related Allowance	5	4	4
Average Investment In Impaired Loans	167	122
Interest Income Recognized		1
Consumer \| Acquired non-credit impaired non-accrual including restructured loans
Loans and Allowance for Loan Losses
Nonaccrual loans	$ 1,208	1,340	1,241
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		1,061
Gross Recorded Investment With Allowance		846
Total Recorded Investment		846
Related Allowance		24
Average Investment In Impaired Loans		634
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	$ 1,049	$ 3,058	$ 1,979

Nonaccrual TDRs are returned to accruing status after demonstrated sustained repayment performance.

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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-Publisher FASB
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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Amount of allowance for credit losses related to recorded investment.

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