Investment Securities (Schedule Of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2011	Dec. 31, 2010
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	$ 772,910	$ 1,274,258
Securities Available-for-Sale, Gross Unrealized Holding Gains	24,284	34,740
Securities Available-for-Sale, Gross Unrealized Holding Losses	31	11,476
Securities Available-for-Sale, Estimated Fair Value	797,163	1,297,522
Securities Held-to-Maturity, Amortized Cost	843,576	673,570
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	17,978	17,164
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	185	4,620
Securities Held-to-Maturity, Estimated Fair Value	861,369	686,114
Obligations Of U.S. Treasury And Other U.S. Government Sponsored Entities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	223,459	272,301
Securities Available-for-Sale, Gross Unrealized Holding Gains	1,358	2,968
Securities Available-for-Sale, Gross Unrealized Holding Losses		1,956
Securities Available-for-Sale, Estimated Fair Value	224,817	273,313
Obligations Of States And Political Subdivisions [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	3,615	10,815
Securities Available-for-Sale, Gross Unrealized Holding Gains	109	281
Securities Available-for-Sale, Gross Unrealized Holding Losses		52
Securities Available-for-Sale, Estimated Fair Value	3,724	11,044
Securities Held-to-Maturity, Amortized Cost	1,992	3,167
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	7	7
Securities Held-to-Maturity, Gross Unrecognized Holding Losses
Securities Held-to-Maturity, Estimated Fair Value	1,999	3,174
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	544,648	990,204
Securities Available-for-Sale, Gross Unrealized Holding Gains	22,100	30,633
Securities Available-for-Sale, Gross Unrealized Holding Losses		9,425
Securities Available-for-Sale, Estimated Fair Value	566,748	1,011,412
Securities Held-to-Maturity, Amortized Cost	841,584	670,403
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	17,971	17,157
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	185	4,620
Securities Held-to-Maturity, Estimated Fair Value	859,370	682,940
Other Equity Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	1,188	938
Securities Available-for-Sale, Gross Unrealized Holding Gains	717	858
Securities Available-for-Sale, Gross Unrealized Holding Losses	31	43
Securities Available-for-Sale, Estimated Fair Value	$ 1,874	$ 1,753

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

For an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity. The held-to-maturity category is for those securities that the entity has the positive intent and ability to hold until maturity.

+ References

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+ Details

- Definition

This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

+ References+ Details

- Definition

As of the balance sheet date, the excess of fair value over carrying value (amortized cost) of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding gain.

+ References+ Details

- Definition

As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss.

+ References+ Details