Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	$ 1,203,988	$ 1,436,714
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	21,845	10,366
Securities Available-for-Sale, Gross Unrealized Holding Losses	984	10,814
Securities Available-for-Sale, Total Fair value	1,224,849	1,436,266
Securities Held-to-Maturity, Amortized Cost	195,095	149,302
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	5,662	2,260
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	219	134
Securities Held-to-Maturity, Estimated Fair Value	200,538	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	270,000	527,605
Securities Available-for-Sale, Gross Unrealized Holding Losses	855	5,542
Securities Available-for-Sale, Total Fair value	269,145	522,063
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	932,869	907,989
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	20,157	8,776
Securities Available-for-Sale, Gross Unrealized Holding Losses	129	5,272
Securities Available-for-Sale, Total Fair value	952,897	911,493
Securities Held-to-Maturity, Amortized Cost	81,812	101,112
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	1,885	1,526
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	19	134
Securities Held-to-Maturity, Estimated Fair Value	83,678	102,504
Other Equity Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Amortized Cost	1,119	1,120
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	1,688	1,590
Securities Available-for-Sale, Total Fair value	2,807	2,710
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Securities Held-to-Maturity, Amortized Cost	113,283	48,190
Securities Held-to-Maturity, Gross Unrecognized Holding Gains	3,777	734
Securities Held-to-Maturity, Gross Unrecognized Holding Losses	200
Securities Held-to-Maturity, Estimated Fair Value	$ 116,860	$ 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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