Consolidated Statements of Income (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest Income:
Loans and leases, including fees	$ 147,761,000	$ 155,596,000	$ 445,301,000	$ 475,926,000
Securities:
Taxable	8,459,000	10,641,000	27,211,000	30,584,000
Tax-exempt	3,383,000	3,527,000	10,323,000	10,682,000
Dividends	2,108,000	1,297,000	6,007,000	3,609,000
Short-term investments	24,000	16,000	66,000	87,000
Total interest income	161,735,000	171,077,000	488,908,000	520,888,000
Deposits:
Interest-bearing demand and savings	4,256,000	4,190,000	12,249,000	13,604,000
Time	10,803,000	10,229,000	30,677,000	33,115,000
Federal Home Loan Bank short-term borrowings	4,554,000	3,915,000	13,772,000	10,738,000
Other short-term borrowings	2,091,000	2,242,000	6,222,000	6,548,000
Federal Home Loan Bank long-term borrowings	247,000	284,000	735,000	888,000
Other long-term debt	3,319,000	4,268,000	7,030,000	12,743,000
Total interest expense	25,270,000	25,128,000	70,685,000	77,636,000
Net interest income	136,465,000	145,949,000	418,223,000	443,252,000
Provision for loan and lease losses	9,000,000	5,000,000	18,000,000	29,000,000
Net interest income, after provision for loan and lease losses	127,465,000	140,949,000	400,223,000	414,252,000
Noninterest Income:
Service charges on deposit accounts	9,561,000	9,514,000	27,855,000	27,533,000
Vehicle origination and servicing fees	1,691,000	2,907,000	7,574,000	8,668,000
Wealth management commissions and fees	13,199,000	12,606,000	38,587,000	38,285,000
Commissions on property and casualty insurance sales	3,992,000	3,872,000	13,872,000	12,774,000
Other commissions and fees	5,689,000	4,885,000	16,125,000	13,940,000
Income from bank-owned life insurance	1,634,000	1,493,000	4,943,000	4,521,000
Mortgage banking revenue	2,432,000	2,237,000	7,846,000	10,345,000
Capital markets revenue	1,593,000	111,000	3,710,000	4,269,000
Net realized gain (loss) on sales and impairment of securities	0	2,000	3,285,000	(51,000)
Other	4,826,000	3,716,000	8,258,000	12,779,000
Total noninterest income	44,617,000	41,343,000	132,055,000	133,063,000
Noninterest Expenses:
Salaries and employee benefits	68,042,000	61,879,000	201,948,000	191,381,000
Occupancy	12,089,000	11,352,000	37,850,000	33,721,000
Furniture and equipment	4,043,000	3,661,000	12,045,000	10,986,000
Professional and technology services	6,168,000	7,173,000	19,427,000	18,733,000
Advertising and marketing	3,784,000	3,319,000	10,927,000	9,084,000
FDIC insurance	5,038,000	5,421,000	15,084,000	13,760,000
Legal fees	1,699,000	1,774,000	4,882,000	5,454,000
Amortization of intangible assets	2,220,000	2,502,000	7,126,000	8,823,000
Vehicle lease disposal	2,222,000	1,193,000	6,688,000	3,796,000
Other	19,106,000	19,427,000	56,691,000	59,430,000
Total noninterest expenses	124,411,000	117,701,000	372,668,000	355,168,000
Income before income taxes	47,671,000	64,591,000	159,610,000	192,147,000
Provision for income taxes	14,203,000	20,300,000	45,486,000	59,809,000
Net Income	$ 33,468,000	$ 44,291,000	$ 114,124,000	$ 132,338,000
Earnings per common share:
Basic	$ 0.18	$ 0.24	$ 0.61	$ 0.71
Diluted	$ 0.18	$ 0.24	$ 0.61	$ 0.70
Cash dividends per common share	$ 0.09	$ 0.08	$ 0.25	$ 0.16
Average common shares outstanding:
Basic	184,985	187,096	186,683	186,840
Diluted	185,724	188,109	187,445	187,816