Investment Securities HTM Gross Unrealized Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2014	Dec. 31, 2013
HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract
Unrealized losses on held to maturity securities, less than 12 months	$ (2,377)	$ (5,339)
Unrealized losses on held to maturity securities, 12 months or more	(608)	(383)
Total unrealized losses on held to maturity securities	(2,985)	(5,722)
Fair value of unrealized losses on held to maturity securities, less than 12 months	76,708	124,435
Fair value of unrealized losses on held to maturity securities, 12 months or more	11,272	5,010
Total fair value of unrealized losses on held to maturity securities	87,980	129,445
Obligations of state and political subdivisions (municipal securities) [Member]
HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract
Unrealized losses on held to maturity securities, less than 12 months	(2,377)	(5,339)
Unrealized losses on held to maturity securities, 12 months or more	(608)	(383)
Total unrealized losses on held to maturity securities	(2,985)	(5,722)
Fair value of unrealized losses on held to maturity securities, less than 12 months	76,708	124,435
Fair value of unrealized losses on held to maturity securities, 12 months or more	11,272	5,010
Total fair value of unrealized losses on held to maturity securities	$ 87,980	$ 129,445
Number of held to maturity securities in a continuous unrealized loss position less than twelve months	168	298
Number of held to maturity securities in a continuous unrealized loss position for twelve months or more	25	10

Number of held to maturity securities in a continuous unrealized loss position for twelve months or more

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- Definition

Number of held to maturity securities in a continuous unrealized loss position less than twelve months

+ References

No definition available.

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- Definition

Amount of unrealized loss on investments in held-to-maturity securities that have been in a loss position for twelve months or longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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Amount of unrealized loss on investments in held-to-maturity securities.

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- Definition

This item represents the fair value of securities categorized as held-to-maturity which are in an unrealized loss position.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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- Definition

Amount of unrealized loss before deducting unrealized gain on investments in held-to-maturity securities that have been in a loss position for less than twelve months.

+ References

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- Definition

This item represents the fair value of securities categorized as held-to-maturity that have been in a continuous unrealized loss position for less than twelve months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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- Definition

This item represents the fair value of securities categorized as held-to-maturity securities that have been in a continuous unrealized loss position for twelve months or longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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