Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
ASSETS
Cash and due from banks	$ 146,387	$ 163,698	$ 153,997
Interest-bearing deposits with banks	1,617,521	1,544,035	1,417,102
Federal funds sold		400	100
Securities (market value: $575,404, $615,458, and $580,630, respectively)	575,034	614,977	580,059
Loans:
Total loans (net of unearned interest)	3,065,439	3,013,498	2,861,844
Allowance for loan losses	(37,436)	(37,656)	(37,092)
Loans, net	3,028,003	2,975,842	2,824,752
Premises and equipment, net	113,836	111,355	102,801
Other real estate owned	10,088	16,109	14,991
Intangible assets, net	13,158	14,219	10,857
Goodwill	44,545	44,545	44,593
Accrued interest receivable	17,532	18,662	19,863
Other assets	105,607	104,983	98,330
Total assets	5,671,711	5,608,825	5,267,445
LIABILITIES AND STOCKHOLDERS' EQUITY
Noninterest-bearing	1,842,680	1,704,996	1,509,433
Interest-bearing	3,256,968	3,332,739	3,192,566
Total deposits	5,099,648	5,037,735	4,701,999
Short-term borrowings	6,340	8,274	1,400
Accrued interest payable	2,260	2,710	3,107
Long-term borrowings	11,329	18,476	32,121
Other liabilities	25,769	22,506	29,555
Junior subordinated debentures	26,804	36,083	28,866
Total liabilities	5,172,150	5,125,784	4,797,048
Commitments and contingent liabilities
Stockholders' equity:
Common stock, $1.00 par, 20,000,000 shares authorized; shares issued and outstanding: 15,153,991, 15,117,430 and 15,273,181, respectively	15,154	15,118	15,273
Capital surplus	79,181	77,462	74,229
Retained earnings	398,267	381,017	371,150
Accumulated other comprehensive income, net of income tax of $3,746, $5,084 and $5,217, respectively	6,959	9,444	9,745
Total stockholders' equity	499,561	483,041	470,397
Total liabilities and stockholders' equity	5,671,711	5,608,825	5,267,445
Senior preferred stock
Stockholders' equity:
Preferred stock, value
Cumulative preferred stock
Stockholders' equity:
Preferred stock, value