Loans and Allowance for Loan Losses (Details 11) - Acquired loans - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Non-Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	$ 4,341	$ 8,683	$ 18,626
Current	1,103,099	1,319,316	1,358,717
Total acquired loans	1,107,440	1,327,999	1,377,343
Non-Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due	39	57	1,257
Current	16,443	24,042	26,448
Total acquired loans	16,482	24,099	27,705
Non-Credit impaired | Commercial non-owner occupied
Loans and Allowance for Loan Losses
Total Past Due	32		17
Current	42,140	49,476	50,290
Total acquired loans	42,172	49,476	50,307
Non-Credit impaired | Commercial owner occupied real estate
Loans and Allowance for Loan Losses
Total Past Due	288	452	1,091
Current	42,236	61,613	64,329
Total acquired loans	42,524	62,065	65,420
Non-Credit impaired | Consumer owner occupied
Loans and Allowance for Loan Losses
Total Past Due	782	2,250	10,431
Current	541,496	644,125	662,668
Total acquired loans	542,278	646,375	673,099
Non-Credit impaired | Home equity loans
Loans and Allowance for Loan Losses
Total Past Due	1,287	3,289	2,472
Current	201,738	231,660	240,248
Total acquired loans	203,025	234,949	242,720
Non-Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	240	381	514
Current	27,219	40,749	34,558
Total acquired loans	27,459	41,130	35,072
Non-Credit impaired | Other income producing property
Loans and Allowance for Loan Losses
Total Past Due	109	185	436
Current	55,983	64,954	68,121
Total acquired loans	56,092	65,139	68,557
Non-Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	1,564	2,069	2,408
Current	175,844	202,697	212,055
Total acquired loans	177,408	204,766	214,463
Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	35,190	69,783	94,102
Current	737,890	856,984	894,422
Total acquired loans	773,080	926,767	988,524
Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due	4,518	10,406	11,159
Current	50,650	54,856	62,163
Total acquired loans	55,168	65,262	73,322
Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	3,387	4,060	6,142
Current	30,687	40,744	40,846
Total acquired loans	34,074	44,804	46,988
Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	4,595	5,961	8,753
Current	69,037	79,488	81,285
Total acquired loans	73,632	85,449	90,038
Credit impaired | Commercial Loans Greater Than or Equal to $1 Million-CBT
Loans and Allowance for Loan Losses
Total Past Due		2,896	3,625
Current	12,963	12,917	13,472
Total acquired loans	12,963	15,813	17,097
Credit impaired | Commercial real estate
Loans and Allowance for Loan Losses
Total Past Due	8,237	20,939	26,537
Current	258,228	304,170	328,178
Total acquired loans	266,465	325,109	354,715
Credit impaired | Residential real estate
Loans and Allowance for Loan Losses
Total Past Due	14,453	25,521	37,886
Current	316,301	364,723	368,390
Total acquired loans	330,754	390,244	406,276
Credit impaired | Single pay
Loans and Allowance for Loan Losses
Current	24	86	88
Total acquired loans	24	86	88
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	1,746	3,321	12,822
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due		17	1,216
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Commercial non-owner occupied
Loans and Allowance for Loan Losses
Total Past Due	32		17
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Commercial owner occupied real estate
Loans and Allowance for Loan Losses
Total Past Due	245	414	1,054
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Consumer owner occupied
Loans and Allowance for Loan Losses
Total Past Due	116	443	7,429
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Home equity loans
Loans and Allowance for Loan Losses
Total Past Due	658	1,451	1,124
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due		14	218
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Other income producing property
Loans and Allowance for Loan Losses
Total Past Due	97	97	276
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	598	885	1,488
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	8,715	15,986	31,604
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due	960	1,750	700
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	458	451	1,058
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	1,660	2,241	5,070
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit impaired | Commercial real estate
Loans and Allowance for Loan Losses
Total Past Due	1,902	4,350	7,352
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit impaired | Residential real estate
Loans and Allowance for Loan Losses
Total Past Due	3,735	7,194	17,424
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	499	1,698	1,481
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired | Commercial owner occupied real estate
Loans and Allowance for Loan Losses
Total Past Due	4
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired | Consumer owner occupied
Loans and Allowance for Loan Losses
Total Past Due	150	241	664
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired | Home equity loans
Loans and Allowance for Loan Losses
Total Past Due	92	866	403
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	2	250	56
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired | Other income producing property
Loans and Allowance for Loan Losses
Total Past Due	7		75
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	244	341	283
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	4,824	5,333	10,009
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due	983	452	529
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	153	196	456
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	630	1,106	1,517
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit impaired | Commercial real estate
Loans and Allowance for Loan Losses
Total Past Due	1,145	723	2,723
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit impaired | Residential real estate
Loans and Allowance for Loan Losses
Total Past Due	1,913	2,856	4,784
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	2,096	3,664	4,323
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due	39	40	41
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Commercial owner occupied real estate
Loans and Allowance for Loan Losses
Total Past Due	39	38	37
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Consumer owner occupied
Loans and Allowance for Loan Losses
Total Past Due	516	1,566	2,338
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Home equity loans
Loans and Allowance for Loan Losses
Total Past Due	537	972	945
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	238	117	240
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Other income producing property
Loans and Allowance for Loan Losses
Total Past Due	5	88	85
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	722	843	637
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired
Loans and Allowance for Loan Losses
Total Past Due	21,651	48,464	52,489
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired | Construction and land development
Loans and Allowance for Loan Losses
Total Past Due	2,575	8,204	9,930
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired | Commercial and industrial
Loans and Allowance for Loan Losses
Total Past Due	2,776	3,413	4,628
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired | Consumer
Loans and Allowance for Loan Losses
Total Past Due	2,305	2,614	2,166
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired | Commercial Loans Greater Than or Equal to $1 Million-CBT
Loans and Allowance for Loan Losses
Total Past Due		2,896	3,625
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired | Commercial real estate
Loans and Allowance for Loan Losses
Total Past Due	5,190	15,866	16,462
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit impaired | Residential real estate
Loans and Allowance for Loan Losses
Total Past Due	$ 8,805	$ 15,471	$ 15,678