Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	$ 1,281,357	$ 1,436,714
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	24,353	10,366
Securities Available-for-Sale, Gross Unrealized Holding Losses	136	10,814
Securities Available-for-Sale, Total Fair value	1,305,574	1,436,266
Securities Held-to-Maturity, Amortized Cost	184,121	149,302
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	7,464	2,260
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	28	134
Securities Held-to-Maturity, Estimated Fair Value	191,557	151,428
Obligations Of U.S. Treasury And Other U.S. Government Sponsored Entities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	360,000	527,605
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	392
Securities Available-for-Sale, Gross Unrealized Holding Losses	25	5,542
Securities Available-for-Sale, Total Fair value	360,367	522,063
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	920,237	907,989
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	22,453	8,776
Securities Available-for-Sale, Gross Unrealized Holding Losses	111	5,272
Securities Available-for-Sale, Total Fair value	942,579	911,493
Securities Held-to-Maturity, Amortized Cost	89,957	101,112
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	2,060	1,526
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	28	134
Securities Held-to-Maturity, Estimated Fair Value	91,989	102,504
Other Equity Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	1,120	1,120
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	1,508	1,590
Securities Available-for-Sale, Total Fair value	2,628	2,710
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Securities Held-to-Maturity, Amortized Cost	94,164	48,190
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	5,404	734
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	0
Securities Held-to-Maturity, Estimated Fair Value	$ 99,568	$ 48,924

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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