Consolidated Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 133,727	$ 139,635
Short-term interest bearing accounts	8,936	7,001
Securities available for sale, at fair value	1,071,654	1,013,171
Securities held to maturity (fair value $461,224 and $454,994, respectively)	456,773	454,361
Trading securities	8,265	7,793
Federal Reserve and Federal Home Loan Bank stock	27,762	32,626
Loans	5,623,023	5,595,271
Less allowance for loan losses	65,359	66,359
Net loans	5,557,664	5,528,912
Premises and equipment, net	88,150	89,258
Goodwill	263,634	263,634
Intangible assets, net	19,084	20,317
Bank owned life insurance	114,342	114,251
Other assets	113,870	126,967
Total assets	7,863,861	7,797,926
Liabilities
Demand (noninterest bearing)	1,797,879	1,838,622
Savings, NOW, and money market	3,685,121	3,417,160
Time	996,437	1,043,823
Total deposits	6,479,437	6,299,605
Short-term borrowings	193,172	316,802
Long-term debt	130,775	130,945
Junior subordinated debt	101,196	101,196
Other liabilities	81,787	85,197
Total liabilities	6,986,367	6,933,745
Stockholders' equity
Preferred stock, $0.01 par value. Authorized 2,500,000 shares at March 31, 2015 and December 31, 2014	0	0
Common stock, $0.01 par value. Authorized 100,000,000 shares at March 31, 2015 and December 31, 2014; issued 49,651,494 at March 31, 2015 and December 31, 2014	497	497
Additional paid-in-capital	575,928	576,504
Retained earnings	432,840	423,956
Accumulated other comprehensive loss	(13,531)	(17,027)
Common stock in treasury, at cost, 5,674,678 and 5,755,040 shares at March 31, 2015 and December 31, 2014, respectively	(118,240)	(119,749)
Total stockholders' equity	877,494	864,181
Total liabilities and stockholders' equity	$ 7,863,861	$ 7,797,926