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	$ 297,918	$ 309,240	$ 324,118
Interest on securities:
Taxable	66,950	75,843	77,078
Tax exempt	5,423	5,545	5,577
Interest on federal funds sold and securities purchased under reverse repurchase agreements	26	30	36
Other interest income	1,342	1,321	1,409
Total Interest Income	371,659	391,979	408,218
Interest Expense
Interest on deposits	24,604	36,294	48,657
Interest on federal funds purchased and securities sold under repurchase agreements	588	965	1,183
Other interest expense	5,477	5,777	6,355
Total Interest Expense	30,669	43,036	56,195
Net Interest Income	340,990	348,943	352,023
Provision for loan losses, LHFI	6,766	29,704	49,546
Provision for loan losses, acquired loans	5,528	624	0
Net Interest Income After Provision for Loan Losses	328,696	318,615	302,477
Noninterest Income
Service charges on deposit accounts	50,351	51,707	55,183
Bank card and other fees	30,445	27,474	25,014
Insurance commissions	28,205	26,966	27,691
Mortgage banking, net	40,960	26,812	29,345
Wealth management	23,056	22,962	21,872
Other, net	1,113	3,853	4,493
Securities gains, net	1,059	80	2,329
Total Noninterest Income	175,189	159,854	165,927
Noninterest Expense
Salaries and employee benefits	190,519	178,556	174,582
Services and fees	46,751	43,858	41,949
Equipment expense	20,478	20,177	17,135
Net occupancy - premises	20,267	20,254	19,808
ORE/Foreclosure expense	11,165	16,293	24,377
FDIC assessment expense	6,502	7,984	12,161
Other expense	48,820	42,728	35,637
Total Noninterest Expense	344,502	329,850	325,649
Income Before Income Taxes	159,383	148,619	142,755
Income taxes	42,100	41,778	42,119
Net Income	$ 117,283	$ 106,841	$ 100,636
Earnings Per Common Share
Basic (in dollars per share)	$ 1.81	$ 1.67	$ 1.58
Diluted (in dollars per share)	$ 1.81	$ 1.66	$ 1.57