Investments Equity Investments, by Category (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Mutual Fund
Schedule of Equity Investments
Fair Value	$ 65,453	$ 50,016
Percent of Total	56.10%	61.80%
Public Utility, Equities
Schedule of Equity Investments
Fair Value	$ 3,663	$ 1,759
Percent of Total	3.10%	2.20%
Common Stock
Schedule of Equity Investments
Fair Value	$ 44,492	$ 27,198
Percent of Total	38.20%	33.60%
Nonredeemable Preferred Stock
Schedule of Equity Investments
Fair Value	$ 3,002	$ 2,005
Percent of Total	2.60%	2.40%
Equity Securities
Schedule of Equity Investments
Fair Value	$ 116,610	$ 80,978
Percent of Total	100.00%	100.00%