Investments - Unrealized losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Schedule of Available-for-sale Securities
Less than 12 Months, Fair Value	$ 86,473		$ 80,631
Less than 12 Months, Unrealized Losses	(762)		(702)
12 Months or More, Fair Value	24,178		48,027
12 Months or More, Unrealized Losses	(318)		(645)
Total Fair Value	110,651		128,658
Total Unrealized Losses	(1,080)		(1,347)
U.S. Government agencies
Schedule of Available-for-sale Securities
Less than 12 Months, Fair Value	26,143		10,950
Less than 12 Months, Unrealized Losses	(257)	(193)
12 Months or More, Fair Value	0		1,737
12 Months or More, Unrealized Losses	0	(50)
Total Fair Value	26,143		12,687
Total Unrealized Losses	(257)		(243)
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities
Less than 12 Months, Fair Value	13,503		16,776
Less than 12 Months, Unrealized Losses	(135)	(89)
12 Months or More, Fair Value	3,741		15,290
12 Months or More, Unrealized Losses	(98)	(225)
Total Fair Value	17,244		32,066
Total Unrealized Losses	(233)		(314)
Held-to-maturity Securities
Less than 12 Months, Fair Value	1,062		1,067
Less than 12 Months, Unrealized Losses	(7)		(6)
12 Months or More, Fair Value	0		0
12 Months or More, Unrealized Losses	0		0
Total Fair Value	1,062		1,067
Total Unrealized Losses	(7)		(6)
U.S. Government agencies collateralized by residential mortgage obligations
Schedule of Available-for-sale Securities
Less than 12 Months, Fair Value	46,827		52,905
Less than 12 Months, Unrealized Losses	(370)	(420)
12 Months or More, Fair Value	20,437		31,000
12 Months or More, Unrealized Losses	(220)	(370)
Total Fair Value	67,264		83,905
Total Unrealized Losses	(590)		(790)
Other equity securities
Schedule of Available-for-sale Securities
Less than 12 Months, Fair Value			0
Less than 12 Months, Unrealized Losses		0
12 Months or More, Fair Value			0
12 Months or More, Unrealized Losses		0
Total Fair Value			0
Total Unrealized Losses			$ 0

Amount of unrealized loss on securities classified as available-for-sale that have been in a loss position for twelve months or longer.

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Amount of unrealized loss on investments in available-for-sale securities that have been in a loss position for less than twelve months.

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