Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest income:
Loans, including fees	$ 232,974	$ 216,756	$ 462,892	$ 432,026
Investment securities available for sale	16,685	14,175	33,655	28,117
Trading account assets	12	117	34	224
Mortgage loans held for sale	650	766	1,238	1,397
Federal Reserve Bank balances	1,020	947	2,019	1,592
Other earning assets	1,052	893	1,878	1,698
Total interest income	252,393	233,654	501,716	465,054
Interest expense:
Deposits	16,200	16,813	32,214	31,631
Federal funds purchased and securities sold under repurchase agreements	51	46	96	89
Long-term debt	14,693	13,151	29,763	26,427
Total interest expense	30,944	30,010	62,073	58,147
Net interest income	221,449	203,644	439,643	406,907
Provision for loan losses	6,693	6,636	16,070	11,034
Net interest income after provision for loan losses	214,756	197,008	423,573	395,873
Non-interest income:
Service charges on deposit accounts	20,240	19,795	39,950	38,928
Fiduciary and asset management fees	11,580	11,843	22,854	23,414
Brokerage revenue	7,338	6,782	13,821	14,032
Mortgage banking income	5,941	7,511	11,425	13,995
Bankcard fees	8,346	8,499	16,718	16,576
Investment securities gains, net	0	1,985	67	2,710
Other fee income	5,280	4,605	10,084	9,851
Other non-interest income	9,161	7,812	16,114	15,181
Total non-interest income	67,886	68,832	131,033	134,687
Non-interest expense:
Salaries and other personnel expense	97,061	94,565	198,419	191,054
Net occupancy and equipment expense	26,783	26,541	53,360	52,713
Third-party processing expense	11,698	10,672	22,814	21,015
FDIC insurance and other regulatory fees	6,625	6,767	13,344	13,725
Professional fees	6,938	6,417	13,307	12,011
Advertising expense	7,351	2,865	9,761	6,309
Foreclosed real estate expense, net	4,588	4,351	7,272	13,847
Loss on early extinguishment of debt	0	0	4,735	0
Restructuring charges, net	5,841	5	6,981	(102)
Other operating expenses	21,726	25,623	46,851	46,141
Total non-interest expense	188,611	177,806	376,844	356,713
Income before income taxes	94,031	88,034	177,762	173,847
Income tax expense	33,574	32,242	64,773	64,091
Net income	60,457	55,792	112,989	109,756
Dividends on preferred stock	2,559	2,559	5,119	5,119
Net income available to common shareholders	$ 57,898	$ 53,233	$ 107,870	$ 104,637
Net income per common share, basic (in dollars per share)	$ 0.46	$ 0.40	$ 0.85	$ 0.78
Net income per common share, diluted (in dollars per share)	$ 0.46	$ 0.40	$ 0.85	$ 0.78
Weighted average common shares outstanding, basic (in shares)	125,100	132,947	126,164	133,935
Weighted average common shares outstanding, diluted (in shares)	125,699	133,625	126,778	134,678