Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest income:
Loans, including fees	$ 77,344	$ 79,857	$ 231,752	$ 238,111
Investment securities:
Taxable	4,309	4,106	13,579	11,590
Tax-exempt	962	1,112	2,970	3,262
Federal funds sold and securities purchased under agreements to resell	666	487	2,174	1,362
Total interest income	83,281	85,562	250,475	254,325
Interest expense:
Deposits	1,412	1,811	4,380	5,550
Federal funds purchased and securities sold under agreements to repurchase	137	95	418	296
Other borrowings	487	641	1,431	2,138
Total interest expense	2,036	2,547	6,229	7,984
Net interest income	81,245	83,015	244,246	246,341
Provision for loan losses	912	1,075	6,198	5,038
Net interest income after provision for loan losses	80,333	81,940	238,048	241,303
Noninterest income:
Fees on deposit accounts	20,776	19,212	62,439	53,403
Mortgage banking income	6,286	4,817	16,104	18,532
Trust and investment services income	4,877	5,489	14,573	15,474
Securities losses, net			122
Amortization of FDIC indemnification assets		(1,871)	(5,901)	(7,120)
Recoveries on acquired loans	2,207	879	5,130	2,099
Other	1,194	1,245	5,032	3,970
Total noninterest income	35,340	29,771	97,499	86,358
Noninterest expense:
Salaries and employee benefits	41,972	40,013	123,941	120,754
Net occupancy expense	5,464	5,395	16,364	15,678
Information services expense	5,237	4,736	15,353	13,076
Furniture and equipment expense	3,234	2,554	9,157	8,461
OREO expense and loan related	2,085	2,717	4,733	7,750
Bankcard expense	2,940	2,448	8,859	6,713
Amortization of intangibles	1,891	2,078	5,687	6,058
Supplies, printing and postage expense	1,345	1,377	4,910	4,391
Professional fees	1,758	1,383	4,663	4,377
FDIC assessment and other regulatory charges	1,001	1,248	3,162	3,685
Advertising and marketing	790	1,054	2,293	2,918
Branch and conversion related expense	709	3,091	3,240	5,328
Other	4,765	5,100	16,712	16,019
Total noninterest expense	73,191	73,194	219,074	215,208
Earnings:
Income before provision for income taxes	42,482	38,517	116,473	112,453
Provision for income taxes	14,387	13,377	39,368	38,515
Net income	28,095	25,140	77,105	73,938
Net income	$ 28,095	$ 25,140	$ 77,105	$ 73,938
Earnings per common share:
Basic (in dollars per share)	$ 1.17	$ 1.05	$ 3.21	$ 3.09
Diluted (in dollars per share)	1.16	1.04	3.18	3.05
Dividends per common share (in dollars per share)	$ 0.31	$ 0.25	$ 0.89	$ 0.72
Weighted-average common shares outstanding:
Basic (in shares)	24,016	23,984	23,989	23,956
Diluted (in shares)	24,278	24,285	24,229	24,235