Consolidated Statements of Financial Position (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash and cash equivalents:
Cash and cash due from banks	$ 144,892,000	$ 130,811,000
Interest-bearing deposits with the Federal Reserve Bank and other banks	38,128,000	179,977,000
Total cash and cash equivalents	183,020,000	310,788,000	656,135,000
Investment securities:
Available-for-sale, at fair value	748,864,000	684,570,000
Held-to-maturity, at amortized cost (fair value - $315,740 at December 31, 2014 and $268,271 at December 31, 2013)	316,413,000	273,905,000
Total investment securities	1,065,277,000	958,475,000
Loans held-for-sale, at fair value	9,128,000	5,219,000
Loans	5,688,230,000	4,647,621,000
Allowance for loan losses	(75,683,000)	(79,072,000)	(84,491,000)
Net loans	5,612,547,000	4,568,549,000
Premises and equipment	97,496,000	75,308,000
Goodwill	180,128,000	120,164,000
Other intangible assets	33,080,000	13,424,000
Interest receivable and other assets	141,467,000	132,781,000
Total Assets	7,322,143,000	6,184,708,000
Deposits:
Noninterest-bearing	1,591,661,000	1,227,768,000
Interest-bearing	4,487,310,000	3,894,617,000
Total deposits	6,078,971,000	5,122,385,000
Interest payable and other liabilities	56,572,000	38,395,000
Short-term borrowings	389,467,000	327,428,000
Federal Home Loan Bank (FHLB) advances			34,300,000
Total liabilities	6,525,010,000	5,488,208,000
Shareholders' equity:
Preferred stock, no par value:	0	0
Issued and outstanding — 32,774,420 shares at December 31, 2014 and 29,789,825 shares at December 31, 2013	32,774,000	29,790,000
Additional paid in capital	565,166,000	488,177,000
Retained earnings	231,646,000	199,053,000
Accumulated other comprehensive loss	(32,453,000)	(20,520,000)	(31,119,000)
Total shareholders' equity	797,133,000	696,500,000	596,341,000
Total Liabilities and Shareholders' Equity	$ 7,322,143,000	$ 6,184,708,000