Investment Securities (Amortized Cost, Unrealized Gains And Losses, And Fair Value Of Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	$ 2,459,596	$ 2,278,932
Available-for-sale Securities, Unrealized Gains	31,905	31,524
Available-for-sale Securities, Unrealized Losses	(9,023)	(11,901)
Available for sale, at fair value	2,482,478	2,298,555
Held to maturity, at amortized cost	4,699	5,211
Held-to-maturity Securities, Unrealized Gains	582	358
Held-to-maturity Securities, Unrealized Losses	(1)	(15)
Held-to-maturity Securities, Fair Value	5,280	5,554
U.S. Treasury And Agencies [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost		213
Available-for-sale Securities, Unrealized Gains		16
Available-for-sale Securities, Unrealized Losses		0
Available for sale, at fair value		229
Obligations Of States And Political Subdivisions [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	314,305	325,189
Available-for-sale Securities, Unrealized Gains	12,974	14,056
Available-for-sale Securities, Unrealized Losses	(815)	(841)
Available for sale, at fair value	326,464	338,404
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	2,143,275	1,951,514
Available-for-sale Securities, Unrealized Gains	18,866	17,398
Available-for-sale Securities, Unrealized Losses	(8,208)	(11,060)
Available for sale, at fair value	2,153,933	1,957,852
Held to maturity, at amortized cost	4,699	5,088
Held-to-maturity Securities, Unrealized Gains	582	358
Held-to-maturity Securities, Unrealized Losses	(1)	(15)
Held-to-maturity Securities, Fair Value	5,280	5,431
Investments In Mutual Funds And Other Equity Securities [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	2,016	2,016
Available-for-sale Securities, Unrealized Gains	65	54
Available-for-sale Securities, Unrealized Losses	0	0
Available for sale, at fair value	$ 2,081	2,070
Other Investment Securities [Member]
Investment Holdings [Line Items]
Held to maturity, at amortized cost		123
Held-to-maturity Securities, Unrealized Gains		0
Held-to-maturity Securities, Unrealized Losses		0
Held-to-maturity Securities, Fair Value		$ 123

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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

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

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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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Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

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Fair value of investments in debt securities classified as held-to-maturity.

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