Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities
Net cash provided by operating activities	$ 59,408	$ 57,975
Investing activities
Purchases of securities available for sale	(100,129)	(106,521)
Proceeds from sales of securities available for sale	0	9,015
Proceeds from call/maturities of securities available for sale	37,319	42,898
Purchases of securities held to maturity	(151,836)	(70,075)
Proceeds from sales of securities held to maturity	0	4,459
Proceeds from call/maturities of securities held to maturity	124,798	34,670
Net increase in loans	(82,399)	(86,810)
Purchases of premises and equipment	(5,675)	(5,908)
Net cash used in investing activities	(177,922)	(178,272)
Financing activities
Net increase (decrease) in noninterest-bearing deposits	46,746	(7,249)
Net (decrease) increase in interest-bearing deposits	(1,927)	51,186
Net increase in short-term borrowings	23,222	37,565
Repayment of long-term debt	(5,460)	(6,401)
Cash paid for dividends	(10,753)	(8,603)
Cash received on exercise of stock-based compensation	281	239
Excess tax benefit from stock-based compensation	977	155
Net cash provided by financing activities	53,086	66,892
Net decrease in cash and cash equivalents	(65,428)	(53,405)
Cash and cash equivalents at beginning of period	246,648	132,420
Cash and cash equivalents at end of period	181,220	79,015
Supplemental disclosures
Cash paid for interest	12,481	11,086
Cash paid for income taxes	9,300	9,033
Noncash transactions:
Transfers of loans to other real estate owned	6,029	10,914
Financed sales of other real estate owned	$ 634	$ 2,900