Investments Aging of Unrealized Losses by Class (Details) $ in Thousands	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($) security
US Government and Government Agencies and Authorities
Less Than Twelve Months
Number of Securities | security	45	40
Gross unrealized losses	$ 111	$ 166
Fair Value	$ 28,464	$ 26,979
Twelve Months or More
Number of securities | security	55	73
Gross unrealized losses	$ 1,204	$ 1,075
Fair Value	$ 61,264	$ 58,980
Foreign Government Debt Securities
Less Than Twelve Months
Number of Securities | security	5
Gross unrealized losses	$ 16
Fair Value	$ 2,978
Twelve Months or More
Number of securities | security	0
Gross unrealized losses	$ 0
Fair Value	$ 0
US States and Political Subdivisions Debt Securities
Less Than Twelve Months
Number of Securities | security	49	106
Gross unrealized losses	$ 272	$ 734
Fair Value	$ 38,469	$ 91,245
Twelve Months or More
Number of securities | security	91	31
Gross unrealized losses	$ 1,029	$ 389
Fair Value	$ 68,115	$ 19,718
Public Utility, Bonds
Less Than Twelve Months
Number of Securities | security	30	16
Gross unrealized losses	$ 374	$ 44
Fair Value	$ 13,685	$ 7,052
Twelve Months or More
Number of securities | security	19	5
Gross unrealized losses	$ 307	$ 41
Fair Value	$ 7,805	$ 1,016
Corporate Debt Securities
Less Than Twelve Months
Number of Securities | security	351	263
Gross unrealized losses	$ 3,149	$ 871
Fair Value	$ 144,769	$ 134,755
Twelve Months or More
Number of securities | security	208	52
Gross unrealized losses	$ 3,010	$ 338
Fair Value	$ 117,351	$ 16,476
Mortgage Backed Securities
Less Than Twelve Months
Number of Securities | security	87	89
Gross unrealized losses	$ 1,303	$ 475
Fair Value	$ 88,754	$ 76,349
Twelve Months or More
Number of securities | security	135	50
Gross unrealized losses	$ 2,180	$ 477
Fair Value	$ 70,510	$ 15,210
Asset-backed Securities
Less Than Twelve Months
Number of Securities | security	67	18
Gross unrealized losses	$ 136	$ 20
Fair Value	$ 41,871	$ 11,682
Twelve Months or More
Number of securities | security	7	0
Gross unrealized losses	$ 3	$ 0
Fair Value	$ 1,372	$ 0
Redeemable Preferred Stock
Less Than Twelve Months
Number of Securities | security	8	0
Gross unrealized losses	$ 62	$ 0
Fair Value	$ 711	$ 0
Twelve Months or More
Number of securities | security	2	3
Gross unrealized losses	$ 77	$ 74
Fair Value	$ 8,377	$ 303
Fixed Maturities
Less Than Twelve Months
Number of Securities | security	642	532
Gross unrealized losses	$ 5,423	$ 2,310
Fair Value	$ 359,701	$ 348,062
Twelve Months or More
Number of securities | security	517	214
Gross unrealized losses	$ 7,810	$ 2,394
Fair Value	$ 334,794	$ 111,703