Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating Activities
Net income	$ 42,430	$ 39,346
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	9,000	13,500
Gains on sales of loans	(6,041)	(6,439)
Proceeds from sales of loans	181,644	235,010
Loans originated for sale	(165,845)	(224,828)
Net gains on sales of other real estate and repossessed assets	(2,265)	(1,498)
Depreciation of premises and equipment	6,552	6,052
Amortization of intangible assets	2,794	2,935
Gain on sale of investment securities	(1,104)	0
Net amortization of premiums and discounts on investment securities	3,054	3,774
Share-based compensation expense	2,131	1,305
Contributions to defined benefit pension plan	(15,000)	(12,000)
Net decrease in interest receivable and other assets	6,634	12,690
Net decrease in interest payable and other liabilities	(786)	(5,673)
Net cash provided by operating activities	63,198	64,174
Investment securities – available-for-sale:
Proceeds from sales	38,028	0
Proceeds from maturities, calls and principal reductions	121,959	189,681
Purchases	(289,189)	(170,667)
Investment securities – held-to-maturity:
Proceeds from maturities, calls and principal reductions	51,962	43,578
Purchases	(104,733)	(81,734)
Net increase in loans	(371,423)	(216,285)
Proceeds from sales of other real estate and repossessed assets	13,229	18,787
Purchases of premises and equipment and branch bank property, net of disposals	(5,166)	(7,851)
Net cash used in investing activities	(545,333)	(224,491)
Financing Activities
Net increase in interest- and noninterest-bearing demand deposits and savings accounts	393,262	333,771
Net decrease in time deposits	(123,400)	(101,756)
Net increase in short-term borrowings	47,132	7,685
Repayment of FHLB advances	(34,289)	(5,820)
Cash dividends paid	(17,658)	(16,786)
Proceeds from issuance of common stock, net of issuance costs	53,925	0
Proceeds from directors’ stock plans and exercise of stock options, net of shares withheld	517	251
Shares issued, net of shares withheld, for restricted stock units	(379)	(248)
Net cash provided by financing activities	319,110	217,097
Net increase (decrease) in cash and cash equivalents	(163,025)	56,780
Cash and cash equivalents at beginning of period	656,135	381,940
Cash and cash equivalents at end of period	493,110	438,720
Supplemental Disclosure of Cash Flow Information:
Interest paid	13,888	18,625
Loans transferred to other real estate and repossessed assets	4,528	11,272
Closed branch offices transferred to other real estate	382	0
Federal income taxes paid	$ 12,950	$ 5,339