Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest income:
Interest and fees on loans	$ 245,767	$ 266,472	$ 279,985
Interest and dividends on investment securities:
Taxable	41,304	42,338	41,978
Exempt from federal taxes	4,749	4,621	5,298
Interest on deposits in banks	1,050	1,093	520
Interest on federal funds sold	13	22	253
Total interest income	292,883	314,546	328,034
Interest expense:
Interest on deposits	33,533	53,949	73,226
Interest on federal funds purchased	0	0	20
Interest on securities sold under repurchase agreements	695	879	776
Interest on other borrowed funds	0	3	1,347
Interest on long-term debt	1,975	2,433	3,249
Interest on subordinated debentures held by subsidiary trusts	5,828	5,843	6,280
Total interest expense	42,031	63,107	84,898
Net interest income	250,852	251,439	243,136
Provision for loan losses	58,151	66,900	45,300
Net interest income after provision for loan losses	192,701	184,539	197,836
Non-interest income:
Other service charges, commissions and fees	31,689	29,494	28,747
Income from origination and sale of loans	21,153	22,868	30,928
Service charges on deposit accounts	17,647	18,181	20,323
Wealth management revenues	13,157	12,387	10,821
Investment securities gains, net	1,544	170	137
Other income	6,682	7,811	9,734
Total non-interest income	91,872	90,911	100,690
Non-interest expense:
Salaries, wages and employee benefits	111,352	112,667	113,569
Occupancy, net	16,223	16,251	15,898
Furniture and equipment	12,562	13,434	12,405
Outsourced technology services	8,933	9,477	10,567
OREO expense, net of income	8,652	7,670	6,397
FDIC insurance premiums	7,333	10,044	12,130
Mortgage servicing rights amortization	3,225	4,615	7,568
Mortgage servicing rights impairment (recovery)	1,275	(787)	(7,224)
Core deposit intangibles amortization	1,446	1,748	2,131
Other expenses	47,411	45,885	44,269
Total non-interest expense	218,412	221,004	217,710
Income before income tax expense	66,161	54,446	80,816
Income tax expense	21,615	17,090	26,953
Net income	44,546	37,356	53,863
Preferred stock dividends	3,422	3,422	3,422
Net income available to common shareholders	$ 41,124	$ 33,934	$ 50,441
Basic earnings per common share	$ 0.96	$ 0.85	$ 1.61
Diluted earnings per common share	$ 0.96	$ 0.85	$ 1.59