Investment Securities (Amortized Cost, Unrealized Gains And Losses, And Fair Value Of Investment Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	$ 2,526,699	$ 2,278,932
Available-for-sale Securities, Unrealized Gains	20,002	31,524
Available-for-sale Securities, Unrealized Losses	(24,162)	(11,901)
Available for sale, at fair value	2,522,539	2,298,555
Held to maturity, at amortized cost	4,609	5,211
Held-to-maturity Securities, Unrecognized Gains	981	358
Held-to-maturity Securities, Unrecognized Losses	0	(15)
Held-to-maturity Securities, Fair Value	5,590	5,554
Obligations Of States And Political Subdivisions [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	300,998	325,189
Available-for-sale Securities, Unrealized Gains	12,741	14,056
Available-for-sale Securities, Unrealized Losses	(622)	(841)
Available for sale, at fair value	313,117	338,404
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	2,223,742	1,951,514
Available-for-sale Securities, Unrealized Gains	7,218	17,398
Available-for-sale Securities, Unrealized Losses	(23,540)	(11,060)
Available for sale, at fair value	2,207,420	1,957,852
Held to maturity, at amortized cost	4,609	5,088
Held-to-maturity Securities, Unrecognized Gains	981	358
Held-to-maturity Securities, Unrecognized Losses	0	(15)
Held-to-maturity Securities, Fair Value	5,590	5,431
Investments In Mutual Funds And Other Equity Securities [Member]
Investment Holdings [Line Items]
Available-for-sale Securities, Amortized Cost	1,959	2,016
Available-for-sale Securities, Unrealized Gains	43	54
Available-for-sale Securities, Unrealized Losses	0	0
Available for sale, at fair value	$ 2,002	2,070
US Treasury and Government [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
Other Investment Securities [Member]
Investment Holdings [Line Items]
Held to maturity, at amortized cost		123
Held-to-maturity Securities, Unrecognized Gains		0
Held-to-maturity Securities, Unrecognized 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
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of accumulated unrealized gain 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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