Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest income:
Loans, including fees	$ 499,721	$ 284,922	$ 244,124
Securities-taxable	84,321	60,653	70,573
Securities-tax exempt	6,031	5,232	4,555
Federal funds sold and other short term investments	2,131	1,751	4,475
Total interest income	592,204	352,558	323,727
Interest expense:
Deposits	55,691	72,903	84,313
Short-term borrowings	7,034	9,306	10,809
Long-term debt and other interest expense	8,246	136	178
Total interest expense	70,971	82,345	95,300
Net interest income	521,233	270,213	228,427
Provision for loan losses	38,732	65,991	54,590
Net interest income after provision for loan losses	482,501	204,222	173,837
Noninterest income:
Service charges on deposit accounts	55,265	45,335	45,354
Bank card fees	28,879	14,941	11,252
Trust fees	23,940	16,715	15,127
Insurance commissions and fees	16,524	14,461	14,355
Investment and annuity fees	15,016	10,181	8,220
ATM fees	14,052	9,486	7,374
Secondary mortgage market operations	10,484	8,915	5,906
Accretion of indemnification asset	16,689	4,890
Bargain purchase gain on acquisition			33,623
Other income	25,578	12,025	16,047
Securities gains (losses), net	(91)		69
Total noninterest income	206,336	136,949	157,327
Noninterest expense:
Compensation expense	234,071	112,478	95,674
Employee benefits	52,531	29,564	25,775
Salaries and employee benefits	286,602	142,042	121,449
Net occupancy expense	43,220	23,803	20,340
Equipment expense	17,524	10,569	9,849
Data processing expense	43,069	23,646	19,043
Professional services expense	69,931	16,447	12,321
Telecommunications and postage	18,514	11,019	8,474
Advertising	17,687	7,713	5,597
Deposit insurance and regulatory fees	12,980	11,401	12,589
Amortization of intangibles	16,551	2,728	1,417
Other expense	67,936	29,892	22,391
Total noninterest expense	594,014	279,260	233,470
Income before income taxes	94,823	61,911	97,694
Income taxes	18,064	9,705	22,919
Net income	$ 76,759	$ 52,206	$ 74,775
Basic earnings per common share	$ 1.16	$ 1.41	$ 2.28
Diluted earnings per common share	$ 1.15	$ 1.40	$ 2.26