Fair Value (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010
Trading securities	$ 2,916	$ 0	$ 0
Investment securities available-for-sale	2,202,855	1,960,222	2,264,467
U.S. Treasury [Member]
Investment securities available-for-sale	62,746	62,550
U.S. Treasury [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	62,746	62,550
U.S. Treasury [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	0	0
U.S. Treasury [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
U.S. Government-Sponsored Entities And Agencies [Member]
Investment securities available-for-sale	387,211	315,133
U.S. Government-Sponsored Entities And Agencies [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
U.S. Government-Sponsored Entities And Agencies [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	387,211	315,133
U.S. Government-Sponsored Entities And Agencies [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
Mortgage-Backed Securities - Agency [Member]
Investment securities available-for-sale	1,104,089	944,446
Mortgage-Backed Securities - Agency [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
Mortgage-Backed Securities - Agency [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	1,104,089	944,446
Mortgage-Backed Securities - Agency [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
Mortgage-Backed Securities - Non-Agency Group 1 [Member]
Investment securities available-for-sale	103,535	126,806
Mortgage-Backed Securities - Non-Agency Group 1 [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
Mortgage-Backed Securities - Non-Agency Group 1 [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	103,535	126,806
Mortgage-Backed Securities - Non-Agency Group 1 [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
States And Political Subdivisions [Member]
Investment securities available-for-sale	368,421	348,924
States And Political Subdivisions [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
States And Political Subdivisions [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	368,421	348,924
States And Political Subdivisions [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
Pooled Trust Preferred Securities Group 1 [Member]
Investment securities available-for-sale	9,738	8,400
Pooled Trust Preferred Securities Group 1 [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
Pooled Trust Preferred Securities Group 1 [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	9,738	8,400
Other Securities [Member]
Investment securities available-for-sale	167,115	153,963
Other Securities [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
Other Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	167,115	153,963
Other Securities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
Residential Loans Held For Sale [Member]
Investment securities available-for-sale	6,104	3,819
Residential Loans Held For Sale [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Investment securities available-for-sale	0	0
Residential Loans Held For Sale [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Investment securities available-for-sale	6,104	3,819
Residential Loans Held For Sale [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Investment securities available-for-sale	0	0
Derivative Assets [Member]
Derivative assets	30,969	34,082
Derivative Assets [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Derivative assets	0	0
Derivative Assets [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Derivative assets	30,969	34,082
Derivative Assets [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Derivative assets	0	0
Derivative Liabilities [Member]
Derivative liabilities	26,692	29,721
Derivative Liabilities [Member] \| Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Derivative liabilities	0	0
Derivative Liabilities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Derivative liabilities	26,692	29,721
Derivative Liabilities [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Derivative liabilities	0	0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Trading securities	2,916
Significant Other Observable Inputs (Level 2) [Member]
Trading securities	0
Significant Unobservable Inputs (Level 3) [Member]
Trading securities	$ 0

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading. Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain or loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis.

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- Definition

The total of financial instruments that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for debt and equity securities formerly categorized as available-for-sale or held-to-maturity which the entity held as of the date it opted to account for such securities at fair value. An enterprise may also categorize such a security as trading without the intent to sell it in the near term assuming the decision to categorize the security as trading occurred at acquisition; this is the reason why the trading category of investments in debt and equity securities are bought and sold "principally" for sale in the near term. Transfers into and out of the trading category should be rare. Such financial instruments that are held as of the reporting date are measured at fair value with unrealized holding gains and losses (the difference between fair value and the previously reported carrying amount) included in earnings.

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