Investments - Available-for-sale Securities in Unrealized Loss Positions (Details) $ in Thousands	Sep. 30, 2016 USD ($) security	Dec. 31, 2015 USD ($) security
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	44	248
Greater than 12 months, number of issues | security	19	22
Number of Issues | security	63	270
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 6,928	$ 60,349
Greater than 12 months, fair value	5,176	6,551
Fair Value	12,104	66,900
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(53)	(781)
Greater than 12 months, unrealized losses	(37)	(139)
Unrealized losses	$ (90)	$ (920)
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	22	162
Greater than 12 months, number of issues | security	14	19
Number of Issues | security	36	181
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 6,590	$ 59,567
Greater than 12 months, fair value	4,987	6,472
Fair Value	11,577	66,039
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(29)	(709)
Greater than 12 months, unrealized losses	(26)	(104)
Unrealized losses	$ (55)	$ (813)
U.S. Government obligations
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	5	7
Greater than 12 months, number of issues | security	0	2
Number of Issues | security	5	9
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 1,569	$ 2,580
Greater than 12 months, fair value	0	679
Fair Value	1,569	3,259
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(1)	(7)
Greater than 12 months, unrealized losses	0	(6)
Unrealized losses	$ (1)	$ (13)
State and local government
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	3	8
Greater than 12 months, number of issues | security	0	0
Number of Issues | security	3	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 540	$ 2,688
Greater than 12 months, fair value	0	0
Fair Value	540	2,688
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(10)	(6)
Greater than 12 months, unrealized losses	0	0
Unrealized losses	$ (10)	$ (6)
Corporate debt
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	7	80
Greater than 12 months, number of issues | security	9	12
Number of Issues | security	16	92
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 2,275	$ 21,760
Greater than 12 months, fair value	3,989	3,618
Fair Value	6,264	25,378
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(10)	(438)
Greater than 12 months, unrealized losses	(23)	(45)
Unrealized losses	$ (33)	$ (483)
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	7	67
Greater than 12 months, number of issues | security	5	5
Number of Issues | security	12	72
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 2,206	$ 32,539
Greater than 12 months, fair value	998	2,175
Fair Value	3,204	34,714
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(8)	(258)
Greater than 12 months, unrealized losses	(3)	(53)
Unrealized losses	$ (11)	$ (311)
Common stocks
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Less than 12 months, number of issues | security	22	86
Greater than 12 months, number of issues | security	5	3
Number of Issues | security	27	89
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months, fair value	$ 338	$ 782
Greater than 12 months, fair value	189	79
Fair Value	527	861
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Less than 12 months, unrealized losses	(24)	(72)
Greater than 12 months, unrealized losses	(11)	(35)
Unrealized losses	$ (35)	$ (107)