Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash Flows From Operating Activities:
Net Income	$ 39,346	$ 31,846
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	13,500	20,900
Gains on sales of loans	(6,439)	(3,373)
Proceeds from sales of loans	235,010	150,299
Loans originated for sale	(224,828)	(141,659)
Net gains on sales of other real estate and repossessed assets	(1,498)	(974)
Depreciation of premises and equipment	6,052	6,026
Amortization of intangible assets	2,935	2,700
Net amortization of premiums and discounts on investment securities	3,774	2,809
Share-based compensation expense	1,305	702
Contributions to defined benefit pension plan	(12,000)	0
Net decrease in interest receivable and other assets	12,690	6,227
Net decrease in interest payable and other liabilities	(5,673)	(3,371)
Net cash provided by operating activities	64,174	72,132
Investment securities-available-for-sale:
Proceeds from maturities, calls and principal reductions	189,681	269,373
Purchases	(170,667)	(303,760)
Investment securities-held-to-maturity:
Proceeds from maturities, calls and principal reductions	43,578	43,854
Purchases	(81,734)	(64,793)
Proceeds from redemption of nonmarketable equity securities	0	1,561
Net increase in loans	(216,285)	(114,810)
Proceeds from sales of other real estate and repossessed assets	18,787	12,801
Purchases of premises and equipment and branch bank property, net	(7,851)	(5,288)
Net cash used in investing activities	(224,491)	(161,062)
Cash Flows From Financing Activities:
Net increase in interest- and noninterest-bearing demand deposits and savings accounts	333,771	204,092
Net decrease in time deposits	(101,756)	(55,271)
Net increase in short-term borrowings	7,685	59,595
Repayment of FHLB advances	(5,820)	(28,139)
Cash dividends paid	(16,786)	(16,473)
Proceeds from directors’ stock plans and exercise of stock options	251	245
Shares issued, net of shares withheld, for restricted stock performance units	(248)	0
Net cash provided by financing activities	217,097	164,049
Net increase in cash and cash equivalents	56,780	75,119
Cash and cash equivalents at beginning of period	381,940	536,165
Cash and Cash Equivalents at End of Period	438,720	611,284
Supplemental Disclosure of Cash Flow Information:
Interest paid	18,625	24,804
Loans transferred to other real estate and repossessed assets	11,272	14,329
Federal income taxes paid (refunded)	$ 5,339	$ 2,952