Investments Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	$ 154,847	$ 561,700
Estimated Fair Value, 12 Months or More	60,844	282,665
Estimated Fair Value, Total	215,691	844,365
Unrealized Losses, Less than 12 Months	1,742	21,887
Unrealized Losses, 12 Months or More	2,259	10,802
Unrealized Losses, Total	4,001	32,689
Fixed maturity securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	145,998	490,261
Estimated Fair Value, 12 Months or More	46,701	280,593
Estimated Fair Value, Total	192,699	770,854
Unrealized Losses, Less than 12 Months	1,351	11,932
Unrealized Losses, 12 Months or More	1,287	10,401
Unrealized Losses, Total	2,638	22,333
U.S. Treasury securities
Fixed Maturity Securities
Estimated Fair Value, 12 Months or More		1,777
Estimated Fair Value, Total		1,777
Unrealized Losses, 12 Months or More		30
Unrealized Losses, Total		30
Obligations of states and political subdivisions
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months		80,856
Estimated Fair Value, 12 Months or More		16,049
Estimated Fair Value, Total		96,905
Unrealized Losses, Less than 12 Months		707
Unrealized Losses, 12 Months or More		965
Unrealized Losses, Total		1,672
Residential mortgage-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	61,933	64,101
Estimated Fair Value, 12 Months or More	31,655	138,572
Estimated Fair Value, Total	93,588	202,673
Unrealized Losses, Less than 12 Months	409	694
Unrealized Losses, 12 Months or More	500	4,147
Unrealized Losses, Total	909	4,841
Commercial mortgage-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	36,398	22,652
Estimated Fair Value, 12 Months or More	866	13,117
Estimated Fair Value, Total	37,264	35,769
Unrealized Losses, Less than 12 Months	397	270
Unrealized Losses, 12 Months or More		628
Unrealized Losses, Total	397	898
Other asset-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	21,281	33,866
Estimated Fair Value, 12 Months or More	462	23,532
Estimated Fair Value, Total	21,743	57,398
Unrealized Losses, Less than 12 Months	64	112
Unrealized Losses, 12 Months or More		217
Unrealized Losses, Total	64	329
Corporate and other securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	26,386	288,786
Estimated Fair Value, 12 Months or More	13,718	87,546
Estimated Fair Value, Total	40,104	376,332
Unrealized Losses, Less than 12 Months	481	10,149
Unrealized Losses, 12 Months or More	787	4,414
Unrealized Losses, Total	1,268	14,563
Equity securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	8,849	71,439
Estimated Fair Value, 12 Months or More	14,143	2,072
Estimated Fair Value, Total	22,992	73,511
Unrealized Losses, Less than 12 Months	391	9,955
Unrealized Losses, 12 Months or More	972	401
Unrealized Losses, Total	$ 1,363	$ 10,356