Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Activities:
Net income	$ 81,127	$ 87,888	$ 94,577
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization/accretion	14,074	14,253	15,327
Loan loss provision	11,200	11,200	11,200
Net amortization of deferred loan fees	(506)	(434)	(100)
Decrease (increase) in interest income receivable	2,396	(172)	1,094
(Increase) decrease in deferred tax asset	(6,952)	2,094	(12,335)
Decrease in other assets	142	2,773	23,404
Stock option compensation expense	1,450	1,425	1,380
Tax benefit decrease (increase) upon exercise of stock options	119	248	(1,004)
(Decrease) increase in income taxes payable	(1,439)	2,074	(565)
(Decrease) increase in interest expense payable	(334)	(1,338)	17
Increase (decrease) in other liabilities	17,147	431	(16,767)
Loss on sale of securities available for sale	1,287
Gain on acquisition			(178)
Gain on sale of real estate and other assets	(1,056)	(1,200)	(211)
Write-down/net loss(gain) on sales/ of premises and equipment	117	(398)	(434)
Originations of mortgage loans for resale	(675)	(595)	(332)
Proceeds from sale of mortgage loans originated for resale	707	616	344
Net write-down/loss(gain) on sale of foreclosed assets	660	1,528	(447)
Net Cash Provided By Operating Activities	119,464	120,393	114,970
Investing Activities:
Net repayments of loans	385,042	341,515	299,432
Proceeds from FDIC* loss-sharing agreement	28,423	7,658	41,048
Net cash acquired from acquisition			57,895
Purchases of investment securities available for sale	(384,363)	(290,610)	(482,356)
Proceeds from sale/maturity/calls of securities available for sale	203,036	331,933	201,442
Purchases of investment securities held to maturity	(484,002)	(428,511)
Proceeds from maturity/calls of securities held to maturity	232,226	95,898	146,206
Purchases of premises and equipment	(4,834)	(3,309)	(1,448)
Proceeds from sale of premises and equipment		640	603
Purchases of FRB/FHLB** securities		(14,069)
Proceeds from sale of FRB/FHLB/FHLMC** securities	2,088	1,829	3,948
Proceeds from sale of foreclosed assets	28,081	24,671	31,745
Net Cash Provided By Investing Activities	5,697	67,645	298,515
Financing Activities:
Net (decrease) increase in deposits	(16,835)	118,131	(176,887)
Net decrease in short-term borrowings	(62,001)	(16,868)	(205,819)
Repayments of notes payable		(10,000)
Exercise of stock options/issuance of shares	7,635	14,374	16,688
Tax benefit (decrease) increase upon exercise of stock options	(119)	(248)	1,004
Retirement of common stock including repurchases	(51,499)	(60,505)	(28,719)
Common stock dividends paid	(41,005)	(41,670)	(42,094)
Net Cash (Used) Provided In Financing Activities	(163,824)	3,214	(435,827)
Net Change In Cash and Due from Banks	(38,663)	191,252	(22,342)
Cash and Due from Banks at Beginning of Year	530,045	338,793	361,135
Cash and Due from Banks at End of Year	491,382	530,045	338,793
Supplemental disclosure of noncash activities:
Loans transferred to other real estate owned	11,619	39,453	30,770
Supplemental disclosure of cash flow activity:
Interest paid for the period	6,814	11,271	15,414
Income tax payments for the period	34,111	28,826	50,388
Acquisitions:
Assets acquired			315,083
Liabilities assumed			314,905
Net			$ 178