Investments - Schedule of Available-for-sale and Held-to-Maturity Securities Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 45,985us-gaap_HeldToMaturitySecurities	$ 0us-gaap_HeldToMaturitySecurities
Gross Unrealized Gains	150
Gross Unrealized Losses	(340)
Fair Value	45,795
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	396,782	441,562
Gross Unrealized Gains	5,501	4,358
Gross Unrealized Losses	(2,137)	(11,333)
Fair Value	400,146us-gaap_AvailableForSaleSecurities	434,587us-gaap_AvailableForSaleSecurities
Obligations of U.S. Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	91,355	93,218
Gross Unrealized Gains	624	700
Gross Unrealized Losses	(153)	(388)
Fair Value	91,826	93,530
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	33,997	49,721
Gross Unrealized Gains	1,300	983
Gross Unrealized Losses	(416)	(1,761)
Fair Value	34,881	48,943
Agency mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	271,430	298,623
Gross Unrealized Gains	3,577	2,675
Gross Unrealized Losses	(1,568)	(9,184)
Fair Value	273,439	292,114
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	14,900
Gross Unrealized Gains	0
Gross Unrealized Losses	(325)
Fair Value	14,575
Agency mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	31,085
Gross Unrealized Gains	150
Gross Unrealized Losses	(15)
Fair Value	$ 31,220

Available-For-Sale Debt Securities, Accumulated Gross Unrealized Gain, Before Tax

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Held-to-maturity Securities, Accumulated Unrecognized Holding Gain

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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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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