Investment Securities (Amortized Cost, Unrealized Gains And Losses, And Fair Value Of Investment Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	$ 2,445,089	$ 2,526,699
Available-for-sale securities, unrealized gains	39,273	20,002
Available-for-sale securities, unrealized losses	(2,290)	(24,162)
Available for sale, at fair value	2,482,072	2,522,539
Held to maturity, at amortized cost	4,382	4,609
Held-to-maturity securities, unrealized gains	868	981
Held-to-maturity securities, unrealized losses	0	0
Held-to-maturity securities, fair value	5,250	5,590
Obligations Of States And Political Subdivisions
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	284,421	300,998
Available-for-sale securities, unrealized gains	13,956	12,741
Available-for-sale securities, unrealized losses	(271)	(622)
Available for sale, at fair value	298,106	313,117
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	2,158,709	2,223,742
Available-for-sale securities, unrealized gains	25,233	7,218
Available-for-sale securities, unrealized losses	(2,019)	(23,540)
Available for sale, at fair value	2,181,923	2,207,420
Held to maturity, at amortized cost	4,382	4,609
Held-to-maturity securities, unrealized gains	868	981
Held-to-maturity securities, unrealized losses	0	0
Held-to-maturity securities, fair value	5,250	5,590
Investments In Mutual Funds And Other Equity Securities
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	1,959	1,959
Available-for-sale securities, unrealized gains	84	43
Available-for-sale securities, unrealized losses	0	0
Available for sale, at fair value	$ 2,043	$ 2,002

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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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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