Investment Securities HTM Securities Amortized Cost and Fair Value (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2014	Dec. 31, 2013
Investment securities held to maturity:
Investment securities held to maturity at amortized cost	$ 193,759	$ 175,210
Investment securities held to maturity, gross unrealized gains	2,372	401
Investment securities held to maturity, gross unrealized losses	(2,985)	(5,722)
Investment securities held to maturity, fair value	193,146	169,889
Obligations of state and political subdivisions (municipal securities) [Member]
Investment securities held to maturity:
Investment securities held to maturity at amortized cost	193,759	175,210
Investment securities held to maturity, gross unrealized gains	2,372	401
Investment securities held to maturity, gross unrealized losses	(2,985)	(5,722)
Investment securities held to maturity, fair value	$ 193,146	$ 169,889

Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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

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-Name Accounting Standards Codification

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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

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Amount of unrecognized gain before loss on investments in held-to-maturity securities.

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Amount of unrecognized loss before gain on investments in held-to-maturity securities. Excludes write-down for other than temporary impairment (OTTI).

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