Consolidated Statements of Financial Position (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Cash and cash equivalents:
Cash and cash due from banks	$ 122,288	$ 130,811	$ 101,501
Interest-bearing deposits with the Federal Reserve Bank	260,097	179,977	477,225
Total cash and cash equivalents	382,385	310,788	578,726
Investment securities:
Available-for-sale, at fair value	657,818	684,570	703,622
Held-to-maturity (fair value - $272,407 at March 31, 2014, $268,271 at December 31, 2013 and $261,405 at March 31, 2013)	278,099	273,905	257,749
Total investment securities	935,917	958,475	961,371
Loans held-for-sale, at fair value	3,814	5,219	14,850
Loans	4,753,289	4,647,621	4,185,261
Allowance for loan losses	(78,473)	(79,072)	(82,834)
Net loans	4,674,816	4,568,549	4,102,427
Premises and equipment (net of accumulated depreciation of $102,163 at March 31, 2014, $100,261 at December 31, 2013 and $94,068 at March 31, 2013)	74,779	75,308	73,501
Goodwill	120,164	120,164	120,164
Other intangible assets	12,872	13,424	14,902
Interest receivable and other assets	133,581	132,781	124,587
Total Assets	6,338,328	6,184,708	5,990,528
Deposits:
Noninterest-bearing	1,219,081	1,227,768	1,086,986
Interest-bearing	4,012,212	3,894,617	3,920,372
Total deposits	5,231,293	5,122,385	5,007,358
Interest payable and other liabilities	40,209	38,395	30,931
Short-term borrowings	361,231	327,428	347,484
Total liabilities	5,632,733	5,488,208	5,385,773
Shareholders’ equity:
Preferred stock, no par value: Authorized - 200,000 shares, none issued	0	0	0
Issued and outstanding — 29,865,841 shares at March 31, 2014, 29,789,825 shares at December 31, 2013 and 27,532,377 shares at March 31, 2013	29,866	29,790	27,532
Additional paid-in capital	489,045	488,177	433,648
Retained earnings	205,985	199,053	174,209
Accumulated other comprehensive loss	(19,301)	(20,520)	(30,634)
Total shareholders’ equity	705,595	696,500	604,755
Total Liabilities and Shareholders’ Equity	$ 6,338,328	$ 6,184,708	$ 5,990,528