Investments - Available-for-sale Securities in Unrealized Loss Positions (Details) $ in Thousands	Jun. 30, 2017 USD ($) security	Dec. 31, 2016 USD ($) security
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	115	201
Greater than 12 months, number of issues | security	9	15
Number of Issues | security	124	216
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 55,283	$ 62,307
Greater than 12 months, fair value	1,289	4,341
Fair Value	56,572	66,648
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(982)	(1,260)
Greater than 12 months, unrealized losses	(22)	(36)
Unrealized losses	$ (1,004)	$ (1,296)
Total fixed maturity securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	92	125
Greater than 12 months, number of issues | security	8	13
Number of Issues | security	100	138
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 54,062	$ 59,835
Greater than 12 months, fair value	1,255	4,275
Fair Value	55,317	64,110
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(845)	(1,199)
Greater than 12 months, unrealized losses	(13)	(27)
Unrealized losses	$ (858)	$ (1,226)
U.S. Government obligations
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	14	15
Greater than 12 months, number of issues | security	0	0
Number of Issues | security	14	15
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 6,743	$ 4,539
Greater than 12 months, fair value	0	0
Fair Value	6,743	4,539
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(43)	(36)
Greater than 12 months, unrealized losses	0	0
Unrealized losses	$ (43)	$ (36)
State and local government
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	14	29
Greater than 12 months, number of issues | security	1	1
Number of Issues | security	15	30
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 3,872	$ 8,217
Greater than 12 months, fair value	99	104
Fair Value	3,971	8,321
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(72)	(202)
Greater than 12 months, unrealized losses	(2)	(3)
Unrealized losses	$ (74)	$ (205)
Corporate debt
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	21	22
Greater than 12 months, number of issues | security	2	7
Number of Issues | security	23	29
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 10,604	$ 9,031
Greater than 12 months, fair value	766	3,369
Fair Value	11,370	12,400
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(158)	(239)
Greater than 12 months, unrealized losses	(9)	(15)
Unrealized losses	$ (167)	$ (254)
Commercial mortgage-backed and other asset-backed
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	43	59
Greater than 12 months, number of issues | security	5	5
Number of Issues | security	48	64
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 32,843	$ 38,048
Greater than 12 months, fair value	390	802
Fair Value	33,233	38,850
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(572)	(722)
Greater than 12 months, unrealized losses	(2)	(9)
Unrealized losses	$ (574)	$ (731)
Total equity securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	23	76
Greater than 12 months, number of issues | security	1	2
Number of Issues | security	24	78
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 1,221	$ 2,472
Greater than 12 months, fair value	34	66
Fair Value	1,255	2,538
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(137)	(61)
Greater than 12 months, unrealized losses	(9)	(9)
Unrealized losses	$ (146)	$ (70)
Common stocks
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	23	76
Greater than 12 months, number of issues | security	1	2
Number of Issues | security	24	78
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 1,221	$ 2,472
Greater than 12 months, fair value	34	66
Fair Value	1,255	2,538
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(137)	(61)
Greater than 12 months, unrealized losses	(9)	(9)
Unrealized losses	$ (146)	$ (70)