Consolidated Statements of Income and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest income:
Loans and loans held for sale	$ 103,082	$ 114,555
Investment securities:
Taxable	22,418	21,485
Tax-exempt	3,580	3,195
Total investment securities interest	25,998	24,680
Total interest income	129,080	139,235
Deposits:
Demand-interest bearing	247	184
Savings and money market accounts	5,103	7,845
Certificates and other time deposits	3,524	6,827
Securities sold under agreements to repurchase	268	915
Wholesale borrowings	1,151	1,640
Total interest expense	10,293	17,411
Net interest income	118,787	121,824
Provision for noncovered loan losses	8,129	17,018
Provision for covered loan losses	5,932	5,331
Net interest income after provision for loan losses	104,726	99,475
Other income:
Trust department income	5,627	5,514
Service charges on deposits	14,409	14,910
Credit card fees	10,180	12,207
ATM and other service fees	3,790	2,917
Bank owned life insurance income	3,056	5,241
Investment services and insurance	2,247	2,447
Investment securities gains, net	260	0
Loan sales and servicing income	6,691	2,785
Other operating income	5,466	6,735
Total other income	51,726	52,756
Other expenses:
Salaries, wages, pension and employee benefits	63,973	59,871
Net occupancy expense	8,592	8,594
Equipment expense	7,104	6,836
Stationery, supplies and postage	2,143	2,705
Bankcard, loan processing and other costs	7,653	7,562
Professional services	3,352	5,793
Amortization of intangibles	483	543
FDIC expense	3,720	4,366
Other operating expense	16,748	18,175
Total other expenses	113,768	114,445
Income before income tax expense	42,684	37,786
Income tax expense	12,340	10,226
Net income	30,344	27,560
Other comprehensive income (loss), net of taxes:
Changes in unreaized securities' holding gains and losses	1,884	338
Reclassification for realized securities' gains	(169)	0
Total other comprehensive gain (loss), net of taxes	1,715	338
Comprehensive income	32,059	27,898
Net income available to common shareholders	30,344	27,560
Net income used in diluted EPS calculation	$ 30,344	$ 27,560
Weighted average number of common shares outstanding - basic	109,211	108,769
Average common shares outstanding	109,211	108,770
Basic earnings per common share (in dollars per share)	$ 0.28	$ 0.25
Diluted earnings per common share (in dollars per share)	$ 0.28	$ 0.25
Dividend per common share (in dollars per share)	$ 0.16	$ 0.16