Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest income:
Interest and fees on loans	$ 230,882	$ 245,767	$ 266,472
Interest and dividends on investment securities:
Taxable	36,847	41,304	42,338
Exempt from federal taxes	4,923	4,749	4,621
Interest on deposits in banks	1,235	1,050	1,093
Interest on federal funds sold	13	13	22
Total interest income	273,900	292,883	314,546
Interest expense:
Interest on deposits	22,306	33,533	53,949
Interest on securities sold under repurchase agreements	579	695	879
Interest on other borrowed funds	0	0	3
Interest on long-term debt	1,981	1,975	2,433
Interest in preferred stock pending redemption	131	0	0
Interest on subordinated debentures held by subsidiary trusts	5,117	5,828	5,843
Total interest expense	30,114	42,031	63,107
Net interest income	243,786	250,852	251,439
Provision for Loan Losses Expensed	40,750	58,151	66,900
Net interest income after provision for loan losses	203,036	192,701	184,539
Non-interest income:
Income from the origination and sale of loans	41,790	21,153	22,868
Other service charges, commissions and fees	34,226	31,689	29,494
Service charges on deposit accounts	17,412	17,647	18,181
Wealth management revenues	14,314	13,575	12,387
Investment securities gains, net	348	1,544	170
Other income	6,771	6,264	7,811
Total non-interest income	114,861	91,872	90,911
Non-interest expense:
Salaries and wages	89,833	83,560	83,373
Employee benefits	29,345	27,792	29,294
Occupancy, net	15,786	16,223	16,251
Furniture and equipment	12,859	12,562	13,434
OREO expense, net of income	9,400	8,652	7,670
Outsourced technology services	8,826	8,933	9,477
FDIC insurance premiums	6,470	7,333	10,044
Professional fees	4,044	3,676	3,245
Mortgage servicing rights amortization	3,501	3,225	4,615
Mortgage servicing rights impairment (recovery)	(771)	1,275	(787)
Core deposit intangibles amortization	1,420	1,446	1,748
Other expenses	48,922	43,735	42,640
Total non-interest expense	229,635	218,412	221,004
Income before income tax expense	88,262	66,161	54,446
Income tax expense	30,038	21,615	17,090
Net income	58,224	44,546	37,356
Preferred stock dividends	3,300	3,422	3,422
Net income available to common shareholders	$ 54,924	$ 41,124	$ 33,934
Basic earnings per common share	$ 1.28	$ 0.96	$ 0.85
Diluted earnings per common share	$ 1.27	$ 0.96	$ 0.85