Securities - (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Amortized cost and fair value of securities held to maturity
Amortized Cost	$ 470,597	$ 430,163
Gross Unrealized Gains	17,109	15,438
Gross Unrealized Losses	(1,082)	(3,113)
Fair Value	486,624	442,488
Obligations of other U.S. Government agencies and corporations
Amortized cost and fair value of securities held to maturity
Amortized Cost	165,589	125,081
Gross Unrealized Gains	47	10
Gross Unrealized Losses	(957)	(2,915)
Fair Value	164,679	122,176
Obligations of states and political subdivisions
Amortized cost and fair value of securities held to maturity
Amortized Cost	305,008	305,082
Gross Unrealized Gains	17,062	15,428
Gross Unrealized Losses	(125)	(198)
Fair Value	$ 321,945	$ 320,312

Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

+ References

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Amount before other than temporary impairment (OTTI) accretion, of 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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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