Investments (Schedule of aggregate fair value and unrealized loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Less than 12 months Fair Value	$ 72,329	$ 54,328
Less than 12 months Unrealized Losses	(1,275)	(1,237)
Greater than 12 months Fair Value	1,889	2,425
Greater than 12 months Unrealized Losses	(310)	(343)
Fair Value, Total	74,218	56,753
Unrealized Losses, Total	(1,585)	(1,580)
Fixed income securities [Member]
Less than 12 months Fair Value	65,029	53,284
Less than 12 months Unrealized Losses	(459)	(885)
Greater than 12 months Fair Value	1,427	2,251
Greater than 12 months Unrealized Losses	(156)	(298)
Fair Value, Total	66,456	55,535
Unrealized Losses, Total	(615)	(1,183)
Fixed income securities [Member] | U.S. Government and agencies [Member]
Less than 12 months Fair Value	3,489	2,750
Less than 12 months Unrealized Losses	(37)	(44)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	3,489	2,750
Unrealized Losses, Total	(37)	(44)
Fixed income securities [Member] | Obligations of states and political subdivisions [Member]
Less than 12 months Fair Value	13,148	16,559
Less than 12 months Unrealized Losses	(132)	(396)
Greater than 12 months Fair Value	248	245
Greater than 12 months Unrealized Losses	(3)	(5)
Fair Value, Total	13,396	16,804
Unrealized Losses, Total	(135)	(401)
Fixed income securities [Member] | Corporate securities [Member]
Less than 12 months Fair Value	24,068	13,479
Less than 12 months Unrealized Losses	(77)	(175)
Greater than 12 months Fair Value	1,179	2,006
Greater than 12 months Unrealized Losses	(153)	(293)
Fair Value, Total	25,247	15,485
Unrealized Losses, Total	(230)	(468)
Fixed income securities [Member] | Residential mortgage-backed securities [Member]
Less than 12 months Fair Value	16,373	15,692
Less than 12 months Unrealized Losses	(191)	(215)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	16,373	15,692
Unrealized Losses, Total	(191)	(215)
Fixed income securities [Member] | Commercial mortgage-backed securities [Member]
Less than 12 months Fair Value	1,528	2,513
Less than 12 months Unrealized Losses	(9)	(41)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	1,528	2,513
Unrealized Losses, Total	(9)	(41)
Fixed income securities [Member] | Asset backed securities [Member]
Less than 12 months Fair Value	6,423	2,291
Less than 12 months Unrealized Losses	(13)	(14)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	6,423	2,291
Unrealized Losses, Total	(13)	(14)
Equity Securities [Member]
Less than 12 months Fair Value	7,300	1,044
Less than 12 months Unrealized Losses	(816)	(352)
Greater than 12 months Fair Value	462	174
Greater than 12 months Unrealized Losses	(154)	(45)
Fair Value, Total	7,762	1,218
Unrealized Losses, Total	(970)	(397)
Equity Securities [Member] | Basic materials [Member]
Less than 12 months Fair Value	381	32
Less than 12 months Unrealized Losses	(6)	(1)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	381	32
Unrealized Losses, Total	(6)	(1)
Equity Securities [Member] | Communications [Member]
Less than 12 months Fair Value	1,527	167
Less than 12 months Unrealized Losses	(176)	(81)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	1,527	167
Unrealized Losses, Total	(176)	(81)
Equity Securities [Member] | Consumer, cyclical [Member]
Less than 12 months Fair Value	514	63
Less than 12 months Unrealized Losses	(137)	(5)
Greater than 12 months Fair Value		174
Greater than 12 months Unrealized Losses		(45)
Fair Value, Total	514	237
Unrealized Losses, Total	(137)	(50)
Equity Securities [Member] | Consumer, non-cyclical [Member]
Less than 12 months Fair Value	1,446	239
Less than 12 months Unrealized Losses	(36)	(208)
Greater than 12 months Fair Value	266
Greater than 12 months Unrealized Losses	(109)
Fair Value, Total	1,712	239
Unrealized Losses, Total	(145)	(208)
Equity Securities [Member] | Energy [Member]
Less than 12 months Fair Value	1,764
Less than 12 months Unrealized Losses	(319)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	1,764
Unrealized Losses, Total	(319)
Equity Securities [Member] | Industrial [Member]
Less than 12 months Fair Value	374
Less than 12 months Unrealized Losses	(33)
Greater than 12 months Fair Value
Greater than 12 months Unrealized Losses
Fair Value, Total	374
Unrealized Losses, Total	(33)
Equity Securities [Member] | Technology [Member]
Less than 12 months Fair Value	1,294	543
Less than 12 months Unrealized Losses	(109)	(57)
Greater than 12 months Fair Value	196
Greater than 12 months Unrealized Losses	(45)
Fair Value, Total	1,490	543
Unrealized Losses, Total	$ (154)	$ (57)