Investments, Summary of Realized Investment Gains (Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summary of realized investment gains (losses) [Abstract]
Gains	$ 6,983	$ 9,310
Losses	(1,829)	(142)
Realized investment gains (losses), net	5,154	9,168
Proceeds from sales of investments [Abstract]
Total proceeds	40,917	83,992
Fixed Maturities [Member]
Summary of realized investment gains (losses) [Abstract]
Gains	884	2,226
Losses	(1,829)	(142)
Realized investment gains (losses), net	(945)	2,084
Proceeds from sales of investments [Abstract]
Total proceeds	30,078	72,760
Equity Securities [Member]
Summary of realized investment gains (losses) [Abstract]
Gains	272	1,044
Losses	0	0
Realized investment gains (losses), net	272	1,044
Proceeds from sales of investments [Abstract]
Total proceeds	0	1,579
Other Investments [Member]
Summary of realized investment gains (losses) [Abstract]
Gains	5,827	6,040
Losses	0	0
Realized investment gains (losses), net	5,827	6,040
Proceeds from sales of investments [Abstract]
Total proceeds	$ 10,839	$ 9,653