Consolidated Statements of Financial Position (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Cash and cash equivalents:
Cash and cash due from banks	$ 134,116	$ 130,811	$ 135,839
Interest-bearing deposits with the Federal Reserve Bank	248,022	179,977	357,271
Total cash and cash equivalents	382,138	310,788	493,110
Investment securities:
Available-for-sale, at fair value	576,211	684,570	705,146
Held-to-maturity (fair value - $314,275 at September 30, 2014, $268,271 at December 31, 2013 and $275,866 at September 30, 2013)	318,562	273,905	282,579
Total investment securities	894,773	958,475	987,725
Loans held-for-sale, at fair value	9,347	5,219	7,907
Loans	5,040,920	4,647,621	4,522,671
Allowance for loan losses	(77,006)	(79,072)	(81,532)
Net loans	4,963,914	4,568,549	4,441,139
Premises and equipment (net of accumulated depreciation of $106,418 at September 30, 2014, $100,261 at December 31, 2013 and $98,150 at September 30, 2013)	80,127	75,308	73,690
Goodwill	120,164	120,164	120,164
Other intangible assets	11,958	13,424	13,865
Interest receivable and other assets	134,564	132,781	120,636
Total Assets	6,596,985	6,184,708	6,258,236
Deposits:
Noninterest-bearing	1,344,716	1,227,768	1,162,599
Interest-bearing	4,087,211	3,894,617	4,028,706
Total deposits	5,431,927	5,122,385	5,191,305
Interest payable and other liabilities	40,366	38,395	36,019
Short-term borrowings	323,086	327,428	357,595
Total liabilities	5,795,379	5,488,208	5,584,919
Shareholders’ equity:
Preferred stock, no par value: Authorized - 200,000 shares, none issued	0	0	0
Issued and outstanding — 32,762,591 shares at September 30, 2014, 29,789,825 shares at December 31, 2013 and 29,778,250 shares at September 30, 2013	32,763	29,790	29,778
Additional paid-in capital	564,127	488,177	487,176
Retained earnings	224,222	199,053	191,538
Accumulated other comprehensive loss	(19,506)	(20,520)	(35,175)
Total shareholders’ equity	801,606	696,500	673,317
Total Liabilities and Shareholders’ Equity	$ 6,596,985	$ 6,184,708	$ 6,258,236