Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating Activities
Net income	$ 31,024	$ 29,051
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and accretion	1,296	674
Provision for loan losses	2,372	4,750
Depreciation of premises and equipment	3,408	3,537
Deferred income tax benefit	(1,802)	(877)
Accretion of gain from sale of interest rate floors	(295)	(2,277)
Net periodic employee benefit	289	174
Realized investment securities (gains) losses	(3,756)	0
Net investment securities impairment losses	355	4,845
Increase in value of bank-owned life insurance	(2,455)	(2,645)
Proceeds from bank-owned life insurance	492	657
Decrease (increase) in accrued interest receivable	464	(329)
Increase in other assets	(4,694)	(14,076)
Increase in other liabilities	15,577	11,909
Net Cash Provided by Operating Activities	42,275	35,393
Investing Activities
Proceeds from maturities and calls of securities held-to-maturity	1,338	3,217
Proceeds from sale of money market and mutual fund securities available-for-sale	617,230	677,250
Purchases of money market and mutual fund securities available-for-sale	(617,337)	(661,949)
Proceeds from sales of securities available-for-sale	56,371	10,849
Proceeds from maturities and calls of securities available-for-sale	88,807	84,789
Purchases of securities available-for-sale	(107,050)	(45,494)
Net increase in loans	(61,800)	(37,912)
Purchases of premises and equipment	(3,691)	(4,335)
Net Cash (Used in) Provided by Investing Activities	(26,132)	26,415
Financing Activities
Net increase (decrease) in noninterest-bearing deposits	25,577	(11,219)
Net (decrease) increase in interest-bearing deposits	(2,631)	6,247
Net increase (decrease) in short-term borrowings	15,171	(7,695)
Repayment of long-term debt	0	(67)
Purchases of treasury stock	(21,429)	(12,902)
Proceeds from exercise of stock options	168	46
Dividends paid	(15,591)	(16,083)
Net Cash Provided by (Used in) Financing Activities	1,265	(41,673)
Increase in Cash and Cash Equivalents	17,408	20,135
Cash and cash equivalents at beginning of period	66,379	62,635
Cash and Cash Equivalents at End of Period	$ 83,787	$ 82,770