Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	$ 1,354,661	$ 1,436,714
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	19,729	10,366
Securities Available-for-Sale, Gross Unrealized Holding Losses	2,207	10,814
Securities Available-for-Sale, Total Fair value	1,372,183	1,436,266
Securities Held-to-Maturity, Amortized Cost	171,273	149,302
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	3,334	2,260
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	79	134
Securities Held-to-Maturity, Estimated Fair Value	174,528	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	421,897	527,605
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	201
Securities Available-for-Sale, Gross Unrealized Holding Losses	888	5,542
Securities Available-for-Sale, Total Fair value	421,210	522,063
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	931,644	907,989
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	18,026	8,776
Securities Available-for-Sale, Gross Unrealized Holding Losses	1,319	5,272
Securities Available-for-Sale, Total Fair value	948,351	911,493
Securities Held-to-Maturity, Amortized Cost	96,129	101,112
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	1,896	1,526
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	68	134
Securities Held-to-Maturity, Estimated Fair Value	97,957	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	1,502	1,590
Securities Available-for-Sale, Total Fair value	2,622	2,710
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Securities Held-to-Maturity, Amortized Cost	75,144	48,190
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	1,438	734
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	11
Securities Held-to-Maturity, Estimated Fair Value	$ 76,571	$ 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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