Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Interest income:
Loans, including fees	$ 216,756	$ 215,737	$ 432,026	$ 427,080
Investment securities available for sale	14,175	14,490	28,117	29,746
Trading account assets	117	90	224	251
Mortgage loans held for sale	766	616	1,397	1,018
Federal Reserve Bank balances	947	472	1,592	998
Other earning assets	893	808	1,698	1,502
Total interest income	233,654	232,213	465,054	460,595
Interest expense:
Deposits	16,813	13,521	31,631	27,742
Federal funds purchased and securities sold under repurchase agreements	46	75	89	151
Long-term debt	13,151	13,566	26,427	27,136
Total interest expense	30,010	27,162	58,147	55,029
Net interest income	203,644	205,051	406,907	405,566
Provision for loan losses	6,636	12,284	11,034	21,795
Net interest income after provision for loan losses	197,008	192,767	395,873	383,771
Non-interest income:
Service charges on deposit accounts	19,795	19,238	38,928	38,451
Fiduciary and asset management fees	11,843	11,296	23,414	22,329
Brokerage revenue	6,782	6,707	14,032	12,920
Mortgage banking income	7,511	5,283	13,995	8,794
Bankcard fees	8,499	8,695	16,576	16,212
Investment securities gains, net	1,985	0	2,710	1,331
Other fee income	4,605	4,928	9,851	9,791
Gain on sale of Memphis branches, net	0	0	0	5,789
Other non-interest income	7,812	7,241	15,181	17,952
Total non-interest income	68,832	63,388	134,687	133,569
Non-interest expense:
Salaries and other personnel expense	94,565	92,540	191,054	185,985
Net occupancy and equipment expense	26,541	26,425	52,713	52,480
Third-party processing expense	10,672	9,464	21,015	19,560
FDIC insurance and other regulatory fees	6,767	7,885	13,725	17,531
Professional fees	6,417	8,224	12,011	15,901
Advertising expense	2,865	6,281	6,309	8,757
Foreclosed real estate expense, net	4,351	4,063	13,847	9,745
Visa indemnification charges	354	356	729	752
Restructuring charges, net	5	7,716	(102)	16,293
Other operating expenses	25,269	19,251	45,412	39,361
Total non-interest expense	177,806	182,205	356,713	366,365
Income before income taxes	88,034	73,950	173,847	150,975
Income tax expense	32,242	27,078	64,091	55,686
Net income	55,792	46,872	109,756	95,289
Dividends on preferred stock	2,559	2,559	5,119	5,119
Net income available to common shareholders	$ 53,233	$ 44,313	$ 104,637	$ 90,170
Net income per common share, basic	$ 0.40	$ 0.32	$ 0.78	$ 0.65
Net income per common share, diluted	$ 0.40	$ 0.32	$ 0.78	$ 0.65
Weighted average common shares outstanding, basic	132,947	138,991	133,935	138,961
Weighted average common shares outstanding, diluted	133,625	139,567	134,678	139,535