Investment Securities (Schedule Of Maturities Of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Investment Holdings [Line Items]
Available-for-sale Securities, Three months or less, Amortized Cost	$ 8,077
Available-for-sale Securities, Over three months through twelve months, Amortized Cost	63,008
Available-for-sale Securities, After one year through five years, Amortized Cost	1,620,464
Available-for-sale Securities, After five years through ten years, Amortized Cost	514,770
Available-for-sale Securities, After ten years, Amortized Cost	70,597
Available-for-sale Securities, Amortized Cost	2,278,932
Available-for-sale Securities, Three months or less, Fair Value	8,118
Available-for-sale Securities, Over three months through twelve months, Fair Value	63,755
Available-for-sale Securities, After one year through five years, Fair Value	1,639,949
Available-for-sale Securities, After five years through ten years, Fair Value	511,260
Available-for-sale Securities, After ten years, Fair Value	73,403
Available-for-sale Securities, Fair Value	2,298,555
Held-to-maturity Securities, Three months or less, Amortized Cost	0
Held-to-maturity Securities, Over three months through twelve months, Amortized Cost	138
Held-to-maturity Securities, After one year through five years, Amortized Cost	427
Held-to-maturity Securities, After five years through ten years, Amortized Cost	271
Held-to-maturity Securities, After ten years, Amortized Cost	4,252
Held to maturity, at amortized cost	5,211us-gaap_HeldToMaturitySecurities	5,563us-gaap_HeldToMaturitySecurities
Held-to-maturity Securities, Three months or less, Fair Value	0
Held-to-maturity Securities, Over three months through twelve months, Fair Value	200
Held-to-maturity Securities, After one year through five years, Fair Value	655
Held-to-maturity Securities, After five years through ten years, Fair Value	298
Held-to-maturity Securities, After ten years, Fair Value	4,278
Held-to-maturity Securities, Fair Value	5,554	5,874
Other Investment Securities [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	2,016
Available-for-sale Securities, Fair Value	2,070
Held to maturity, at amortized cost	123
Held-to-maturity Securities, Fair Value	$ 123

Available-for-sale Securities, Debt Maturities, Over Three Months Through Twelve Months, Amortized Cost

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