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	$ 43,822	$ 41,442
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan losses	17,258	13,329
Depreciation and amortization of premises and equipment	5,885	4,636
Net accretion on securities	4,082	1,766
Amortization of intangible assets	3,548	2,530
Stock based compensation	3,571	3,558
Bank owned life insurance income	(2,648)	(2,228)
Purchases of trading securities	(1,022)	(705)
Unrealized gains in trading securities	(345)	(84)
Deferred income tax expense (benefit)	1,126	(2,735)
Proceeds from sale of loans held for sale	59,231	37,922
Originations of loans held for sale	(65,722)	(47,263)
Net gains on sales of loans held for sale	(1,168)	(1,352)
Net security gains	(1,413)	(578)
Net gains on sales of other real estate owned	(654)	(602)
Net decrease in other assets	12,016	9,316
Net increase (decrease) in other liabilities	8,694	(1,213)
Net cash provided by operating activities	86,261	57,739
Investing activities
Net cash provided by acquisitions	80,909	53,121
Securities available for sale:
Proceeds from maturities, calls, and principal paydowns	314,104	381,160
Proceeds from sales	27,593	1,791
Purchases	(303,497)	(329,378)
Securities held to maturity:
Proceeds from maturities, calls, and principal paydowns	24,582	24,428
Purchases	(75,808)	(14,959)
Net increase in loans	(198,057)	(234,330)
Net increase in Federal Reserve and FHLB stock	(5,584)	(672)
Purchases of premises and equipment	(3,409)	(4,805)
Proceeds from sales of other real estate owned	3,470	2,411
Net cash used in investing activities	(135,697)	(121,233)
Financing activities
Net increase in deposits	105,369	156,761
Net increase (decrease) in short-term borrowings	188,689	(44,227)
Repayments of long-term debt	(163,409)	(3,350)
Proceeds from the issuance of shares to employee benefit plans and other stock plans	154	825
Purchase of treasury stock	(12,459)	(15,490)
Cash dividends	(24,334)	(19,966)
Net cash provided by financing activities	94,010	74,553
Net increase in cash and cash equivalents	44,574	11,059
Cash and cash equivalents at beginning of period	163,668	129,381
Cash and cash equivalents at end of period	208,242	140,440
Cash paid during the period for:
Interest	24,335	26,951
Income taxes paid	12,885	18,457
Acquisitions:
Fair value of assets acquired	1,504,415	257,865
Fair value of liabilities assumed	1,284,632	285,012
Fair value of debt issued in asset purchase	$ 0	$ 150