Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash Flows From Operating Activities:
Net Income	$ 26,240	$ 20,221
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	9,000	14,500
Gains on sales of loans	(4,143)	(2,208)
Proceeds from sales of loans	162,143	101,586
Loans originated for sale	(151,807)	(85,773)
Net gains on sales of other real estate and repossessed assets	(941)	(703)
Depreciation of premises and equipment	4,019	4,076
Amortization of intangible assets	2,068	1,904
Net amortization of premiums and discounts on investment securities	2,601	1,713
Share-based compensation expense	786	374
Contributions to defined benefit pension plan	(12,000)
Net decrease in interest receivable and other assets	13,471	10,494
Net decrease in interest payable and other liabilities	380	(3,166)
Net cash provided by operating activities	51,817	63,018
Investment securities-available-for-sale:
Proceeds from maturities, calls and principal reductions	125,613	185,803
Purchases	(140,529)	(220,747)
Investment securities-held-to-maturity:
Proceeds from maturities, calls and principal reductions	34,338	30,763
Purchases	(63,944)	(55,334)
Proceeds from redemption of nonmarketable equity securities		1,561
Net increase in loans	(149,113)	(86,502)
Proceeds from sales of other real estate and repossessed assets	10,350	8,767
Purchases of premises and equipment and branch bank property, net	(5,404)	(3,384)
Net cash used in investing activities	(188,689)	(139,073)
Cash Flows From Financing Activities:
Net increase (decrease) in noninterest-bearing and interest-bearing demand deposits and savings accounts	81,196	(60,655)
Net decrease in time deposits	(64,509)	(20,134)
Net increase (decrease) in short-term borrowings	(4,038)	33,897
Repayment of FHLB advances	(4,880)	(2,202)
Cash dividends paid	(11,006)	(10,982)
Proceeds from directors' stock plans Shares issued, net of shares withheld, for restricted stock performance units	240	245
Shares issued, net of shares withheld, for restricted stock performance units	(248)
Net cash used in financing activities	(3,245)	(59,831)
Net increase in cash and cash equivalents	(140,117)	(135,886)
Cash and cash equivalents at beginning of period	381,940	536,165
Cash and Cash Equivalents at End of Period	241,823	400,279
Supplemental Disclosure of Cash Flow Information:
Interest paid	12,882	17,015
Loans transferred to other real estate and repossessed assets	7,434	5,857
Federal income taxes paid (refunded)	$ 1,350	$ (849)