Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Interest income:
Loans, including fees	$ 229,917	$ 215,269
Investment securities available for sale	16,972	13,943
Trading account assets	22	107
Mortgage loans held for sale	588	632
Federal Reserve Bank balances	999	645
Other earning assets	825	805
Total interest income	249,323	231,401
Interest expense:
Deposits	16,015	14,819
Federal funds purchased and securities sold under repurchase agreements	45	43
Long-term debt	15,070	13,276
Total interest expense	31,130	28,138
Net interest income	218,193	203,263
Provision for loan losses	9,377	4,397
Net interest income after provision for loan losses	208,816	198,866
Non-interest income:
Service charges on deposit accounts	19,710	19,133
Fiduciary and asset management fees	11,274	11,571
Brokerage revenue	6,483	7,251
Mortgage banking income	5,484	6,484
Bankcard fees	8,372	8,077
Investment securities gains, net	67	725
Other fee income	4,804	5,246
Other non-interest income	6,953	7,367
Total non-interest income	63,147	65,854
Non-interest expense:
Salaries and other personnel expense	101,358	96,488
Net occupancy and equipment expense	26,577	26,172
Third-party processing expense	11,116	10,343
FDIC insurance and other regulatory fees	6,719	6,957
Professional fees	6,369	5,594
Advertising expense	2,410	3,443
Foreclosed real estate expense, net	2,684	9,496
Loss on early extinguishment of debt	4,735	0
Restructuring charges, net	1,140	(107)
Other operating expenses	25,125	20,522
Total non-interest expense	188,233	178,908
Income before income taxes	83,730	85,812
Income tax expense	31,199	31,849
Net income	52,531	53,963
Dividends on preferred stock	2,559	2,559
Net income available to common shareholders	$ 49,972	$ 51,404
Net income per common share, basic (in dollars per share)	$ 0.39	$ 0.38
Net income per common share, diluted (in dollars per share)	$ 0.39	$ 0.38
Weighted average common shares outstanding, basic (in shares)	127,227	134,933
Weighted average common shares outstanding, diluted (in shares)	127,857	135,744