Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Interest Income
Loans	$ 324,229		$ 291,465		$ 286,166
Taxable securities	38,659		35,167		30,774
Tax-exempt securities	11,045		11,121		11,842
Deposits in banks	813		216		109
Total interest income	374,746		337,969		328,891
Interest Expense
Deposits	4,800		3,134		2,977
Federal Home Loan Bank advances	1,078		671		474
Interest Expense, Subordinated Notes and Debentures	304		0		0
Other borrowings	575		545		553
Total interest expense	6,757		4,350		4,004
Net Interest Income	367,989		333,619		324,887
Provision for loan and lease losses	8,631		10,778		8,591
Net interest income after provision for loan and lease losses	359,358		322,841		316,296
Noninterest Income
Deposit account and treasury management fees	30,381		28,500		28,451
Card revenue	25,627		23,620		22,690
Financial services and trust revenue	11,478		11,266		12,596
Loan revenue	12,399		10,967		10,932
Merchant Discount Fees	4,283		8,732		8,975
Investment securities gains (losses), net	(11)		1,181		1,581
Gain on sale of merchant card services portfolio	14,000		0		0
Bank owned life insurance	5,380		4,546		4,441
Change in FDIC loss sharing asset	(447)		(2,585)		(4,010)
Other	6,552		1,855		5,817
Total noninterest income	109,642		88,082		91,473
Noninterest Expense
Compensation and employee benefits	169,674		150,282		149,410
Occupancy	32,407		33,734		34,818
Merchant processing	2,196		4,330		4,204
Advertising and promotion	4,466		4,598		4,713
Data processing	18,205		16,488		17,421
Legal and professional fees	15,151		7,889		9,608
Taxes, licenses and fees	4,773		5,185		5,395
Regulatory premiums	3,183		3,777		4,806
Net cost (benefit) of operation of other real estate owned	468		551		(1,629)
Amortization of intangibles	6,333		5,946		6,882
Other	34,161		28,362		30,521
Total noninterest expense	291,017		261,142		266,149
Income before income taxes	177,983		149,781		141,620
Income tax provision	65,155		44,915		42,793
Net Income	$ 112,828		$ 104,866		$ 98,827
Per Common Share
Basic earnings per common share	$ 1.86	[1]	$ 1.81	[1]	$ 1.71
Diluted earnings per common share	$ 1.86	[1]	$ 1.81	[1]	$ 1.71
Weighted average number of common shares outstanding	59,882		57,184		57,019
Weighted average number of diluted common shares outstanding	59,888		57,193		57,032

[1] Due to averaging of shares, quarterly earnings per share may not add up to the totals reported for the full year.