Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating activities
Net income	$ 41,442	$ 44,179
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan and lease losses	13,329	15,161
Depreciation and amortization of premises and equipment	4,636	4,023
Net accretion on securities	1,766	939
Amortization of intangible assets	2,530	2,286
Stock based compensation	3,558	2,436
Bank owned life insurance income	(2,228)	(2,369)
Purchases of trading securities	(705)	(404)
Unrealized (gains) losses in trading securities	(84)	247
Deferred income tax benefit	(2,735)	(4,003)
Proceeds from sales of loans held for sale	37,922	3,257
Originations and purchases of loans held for sale	(47,263)	(2,445)
Net gains on sales of loans held for sale	(1,352)	(2)
Net security gains	(578)	(98)
Net gain on sales of other real estate owned	(602)	(712)
Net decrease in other assets	9,316	3,499
Net (decrease) increase in other liabilities	(1,213)	1,532
Net cash provided by operating activities	57,739	67,526
Investing activities
Net cash provided by (used in) acquisitions	53,121	(1,000)
Securities available for sale:
Proceeds from maturities, calls, and principal paydowns	381,160	360,358
Proceeds from sales	1,791	118
Purchases	(329,378)	(387,855)
Securities held to maturity:
Proceeds from maturities, calls, and principal paydowns	24,428	39,766
Purchases	(14,959)	(14,580)
Net increase in loans	(234,330)	(115,065)
Net (increase) decrease in Federal Reserve and FHLB stock	(672)	226
Purchases of premises and equipment	(4,805)	(5,677)
Proceeds from sales of other real estate owned	2,411	2,073
Net cash (used in) provided by investing activities	(121,233)	(121,636)
Financing activities
Net increase in deposits	156,761	130,712
Net increase in short-term borrowings	(44,227)	(1,149)
Repayments of long-term debt	(3,350)	(2,143)
Issuance of long-term debt	0	156
Excess tax benefit from exercise of stock options	(13)	(95)
Proceeds from the issuance of shares to employee benefit plans and other stock plans	838	723
Purchase of treasury stock	(15,490)	(30,502)
Cash dividends and payment for fractional shares	(19,966)	(20,439)
Net cash provided by financing activities	74,553	77,263
Net increase in cash and cash equivalents	11,059	23,153
Cash and cash equivalents at beginning of period	129,381	168,792
Cash and cash equivalents at end of period	140,440	191,945
Cash paid during the period for:
Interest	26,951	30,774
Income taxes paid	18,457	22,537
Noncash investing activities:
Loans transferred to OREO	1,503	1,110
Acquisitions:
Fair value of assets acquired	257,865	3,460
Fair value of liabilities assumed	285,012	3,426
Fair value of debt issued in purchase combination	$ 150	$ 2,460