Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating activities
Net cash provided by operating activities	$ 90,232	$ 124,122
Investing activities
Purchases of securities available for sale	(100,129)	(106,521)
Proceeds from sales of securities available for sale	724	9,015
Proceeds from call/maturities of securities available for sale	60,202	62,606
Purchases of securities held to maturity	(154,126)	(70,075)
Proceeds from sales of securities held to maturity	0	4,461
Proceeds from call/maturities of securities held to maturity	130,206	84,667
Net increase in loans	(82,319)	(190,010)
Purchases of premises and equipment	(12,494)	(8,685)
Net cash received in acquisition	0	170,061
Net cash used in investing activities	(157,936)	(44,481)
Financing activities
Net increase in noninterest-bearing deposits	79,524	20,770
Net (decrease) increase in interest-bearing deposits	(157,766)	26,735
Net increase (decrease) in short-term borrowings	63,363	(5,394)
Repayment of long-term debt	(7,864)	(7,326)
Cash paid for dividends	(16,135)	(13,951)
Cash received on exercise of stock-based compensation	401	99
Excess tax benefit from stock-based compensation	1,127	155
Net cash (used) provided by financing activities	(37,350)	21,088
Net (decrease) increase in cash and cash equivalents	(105,054)	100,729
Cash and cash equivalents at beginning of period	246,648	132,420
Cash and cash equivalents at end of period	141,594	233,149
Supplemental disclosures
Cash paid for interest	18,674	16,900
Cash paid for income taxes	9,300	9,393
Noncash transactions:
Transfers of loans to other real estate owned	8,318	13,747
Financed sales of other real estate owned	$ 860	$ 6,783