Consolidated Statements of Income (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest Income:
Loans and leases, including fees	$ 155,596,000	$ 163,979,000	$ 475,926,000	$ 478,483,000
Securities:
Taxable	10,641,000	12,277,000	30,584,000	38,025,000
Tax-exempt	3,527,000	3,620,000	10,682,000	11,003,000
Dividends	1,297,000	1,157,000	3,609,000	3,252,000
Short-term investments	16,000	36,000	87,000	101,000
Total interest income	171,077,000	181,069,000	520,888,000	530,864,000
Deposits:
Interest-bearing demand and savings	4,190,000	5,091,000	13,604,000	16,761,000
Time	10,229,000	12,085,000	33,115,000	35,518,000
Federal Home Loan Bank short-term borrowings	3,915,000	3,245,000	10,738,000	9,302,000
Other short-term borrowings	2,242,000	2,206,000	6,548,000	6,507,000
Federal Home Loan Bank long-term borrowings	284,000	308,000	888,000	668,000
Other long-term debt	4,268,000	8,992,000	12,743,000	26,174,000
Total interest expense	25,128,000	31,927,000	77,636,000	94,930,000
Net interest income	145,949,000	149,142,000	443,252,000	435,934,000
Provision for loan and lease losses	5,000,000	16,000,000	29,000,000	51,000,000
Net interest income, after provision for loan and lease losses	140,949,000	133,142,000	414,252,000	384,934,000
Noninterest Income:
Service charges on deposit accounts	9,514,000	9,013,000	27,533,000	25,270,000
Vehicle origination and servicing fees	2,907,000	2,470,000	8,668,000	6,620,000
Wealth management commissions and fees	12,606,000	11,923,000	38,285,000	35,823,000
Commissions on property and casualty insurance sales	3,872,000	3,158,000	12,774,000	12,145,000
Other commissions and fees	5,276,000	5,387,000	17,199,000	14,830,000
Income from bank-owned life insurance	1,493,000	1,726,000	4,521,000	4,868,000
Mortgage banking revenue	2,237,000	5,113,000	10,345,000	12,969,000
Net realized (loss) gain on sales of securities	2,000	31,000	(51,000)	1,633,000
Other	3,436,000	4,840,000	13,789,000	8,829,000
Total noninterest income	41,343,000	43,661,000	133,063,000	122,987,000
Noninterest Expenses:
Salaries and employee benefits	61,879,000	62,236,000	191,801,000	184,718,000
Occupancy	11,352,000	11,350,000	33,721,000	33,886,000
Furniture and equipment	3,661,000	3,823,000	10,986,000	11,749,000
Professional and technology services	7,173,000	4,916,000	18,733,000	14,591,000
Advertising and marketing	3,092,000	2,947,000	8,664,000	9,288,000
FDIC insurance	5,421,000	5,275,000	13,760,000	15,222,000
Legal fees	1,774,000	2,012,000	5,454,000	5,972,000
Amortization of intangible assets	2,502,000	3,337,000	8,823,000	9,253,000
Vehicle lease disposal	1,193,000	1,401,000	3,796,000	4,981,000
Merger related	0	1,500,000	0	16,297,000
Loss on extinguishment of debt	0	5,451,000	0	5,451,000
Other	19,654,000	18,662,000	59,430,000	53,332,000
Total noninterest expenses	117,701,000	122,910,000	355,168,000	364,740,000
Income before income taxes	64,591,000	53,893,000	192,147,000	143,181,000
Provision for income taxes	20,300,000	17,161,000	59,809,000	45,183,000
Net Income	$ 44,291,000	$ 36,732,000	$ 132,338,000	$ 97,998,000
Earnings per common share:
Basic	$ 0.24	$ 0.20	$ 0.71	$ 0.54
Diluted	$ 0.24	$ 0.20	$ 0.70	$ 0.54
Cash dividends per common share	$ 0.08	$ 0.06	$ 0.16	$ 0.14
Average common shares outstanding:
Basic	187,096	186,214	186,840	181,735
Diluted	188,109	187,004	187,816	182,487