Securities Securities - (Premium Amortization and Discount Accretion Included in Income on Securities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments, Debt and Equity Securities [Abstract]
Premium Amortization	$ (68,070)	$ (49,112)	$ (28,364)
Discount Accretion	6,802	7,191	6,663
Net (Premium Amortization) Discount Accretion	$ (61,268)	$ (41,921)	$ (21,701)

Amount of accretion of purchase discount on nonoperating securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Amount of amortization of purchase premium on nonoperating securities.

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Amount of accretion (amortization) of purchase discount (premium) on nonoperating securities.

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