Loans and Allowance for Loan Losses (Details 8) - Non-acquired loans - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Loans and Allowance for Loan Losses
Total loans	$ 3,994,716	$ 3,467,826	$ 3,304,708
Pass
Loans and Allowance for Loan Losses
Total loans	3,843,597	3,286,228	3,116,316
Special mention
Loans and Allowance for Loan Losses
Total loans	98,527	118,790	125,847
Substandard
Loans and Allowance for Loan Losses
Total loans	52,570	62,786	61,623
Doubtful
Loans and Allowance for Loan Losses
Total loans	22	22	922
Commercial loans
Loans and Allowance for Loan Losses
Total loans	2,423,579	2,162,575	2,095,593
Commercial loans | Pass
Loans and Allowance for Loan Losses
Total loans	2,322,346	2,036,266	1,964,367
Commercial loans | Special mention
Loans and Allowance for Loan Losses
Total loans	72,445	87,850	91,970
Commercial loans | Substandard
Loans and Allowance for Loan Losses
Total loans	28,788	38,459	39,256
Construction and land development
Loans and Allowance for Loan Losses
Total loans	372,077	364,221	385,318
Construction and land development | Pass
Loans and Allowance for Loan Losses
Total loans	349,808	337,641	358,474
Construction and land development | Special mention
Loans and Allowance for Loan Losses
Total loans	15,629	15,466	16,433
Construction and land development | Substandard
Loans and Allowance for Loan Losses
Total loans	6,640	11,114	10,411
Commercial non-owner occupied
Loans and Allowance for Loan Losses
Total loans	406,489	333,590	318,470
Commercial non-owner occupied | Pass
Loans and Allowance for Loan Losses
Total loans	388,303	307,450	292,231
Commercial non-owner occupied | Special mention
Loans and Allowance for Loan Losses
Total loans	14,888	20,596	20,412
Commercial non-owner occupied | Substandard
Loans and Allowance for Loan Losses
Total loans	3,298	5,544	5,827
Commercial owner occupied real estate
Loans and Allowance for Loan Losses
Total loans	1,012,428	907,913	881,403
Commercial owner occupied real estate | Pass
Loans and Allowance for Loan Losses
Total loans	970,090	858,220	827,322
Commercial owner occupied real estate | Special mention
Loans and Allowance for Loan Losses
Total loans	28,799	34,737	39,261
Commercial owner occupied real estate | Substandard
Loans and Allowance for Loan Losses
Total loans	13,539	14,956	14,820
Commercial and industrial
Loans and Allowance for Loan Losses
Total loans	462,588	405,923	355,580
Commercial and industrial | Pass
Loans and Allowance for Loan Losses
Total loans	456,912	397,555	346,394
Commercial and industrial | Special mention
Loans and Allowance for Loan Losses
Total loans	4,321	6,718	7,786
Commercial and industrial | Substandard
Loans and Allowance for Loan Losses
Total loans	1,355	1,650	1,400
Other income producing property
Loans and Allowance for Loan Losses
Total loans	169,997	150,928	154,822
Other income producing property | Pass
Loans and Allowance for Loan Losses
Total loans	157,233	135,400	139,946
Other income producing property | Special mention
Loans and Allowance for Loan Losses
Total loans	8,808	10,333	8,078
Other income producing property | Substandard
Loans and Allowance for Loan Losses
Total loans	3,956	5,195	6,798
Consumer loans
Loans and Allowance for Loan Losses
Total loans	1,571,137	1,305,251	1,209,115
Consumer loans | Pass
Loans and Allowance for Loan Losses
Total loans	1,521,251	1,249,962	1,151,949
Consumer loans | Special mention
Loans and Allowance for Loan Losses
Total loans	26,082	30,940	33,877
Consumer loans | Substandard
Loans and Allowance for Loan Losses
Total loans	23,782	24,327	22,367
Consumer loans | Doubtful
Loans and Allowance for Loan Losses
Total loans	22	22	922
Consumer owner occupied
Loans and Allowance for Loan Losses
Total loans	987,863	786,778	702,521
Consumer owner occupied | Pass
Loans and Allowance for Loan Losses
Total loans	953,523	746,847	660,578
Consumer owner occupied | Special mention
Loans and Allowance for Loan Losses
Total loans	17,198	22,129	24,144
Consumer owner occupied | Substandard
Loans and Allowance for Loan Losses
Total loans	17,142	17,802	16,899
Consumer owner occupied | Doubtful
Loans and Allowance for Loan Losses
Total loans			900
Home equity loans
Loans and Allowance for Loan Losses
Total loans	308,563	283,934	276,341
Home equity loans | Pass
Loans and Allowance for Loan Losses
Total loans	294,712	269,844	262,080
Home equity loans | Special mention
Loans and Allowance for Loan Losses
Total loans	7,987	8,047	9,097
Home equity loans | Substandard
Loans and Allowance for Loan Losses
Total loans	5,842	6,021	5,142
Home equity loans | Doubtful
Loans and Allowance for Loan Losses
Total loans	22	22	22
Consumer
Loans and Allowance for Loan Losses
Total loans	223,210	189,317	183,451
Consumer | Pass
Loans and Allowance for Loan Losses
Total loans	221,515	188,049	182,489
Consumer | Special mention
Loans and Allowance for Loan Losses
Total loans	897	764	636
Consumer | Substandard
Loans and Allowance for Loan Losses
Total loans	798	504	326
Other Loans
Loans and Allowance for Loan Losses
Total loans	51,501	45,222	46,802
Other Loans | Pass
Loans and Allowance for Loan Losses
Total loans	$ 51,501	$ 45,222	$ 46,802