Unaudited Interim Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed maturities, available-for-sale, amortized cost	$ 1,587,004	$ 1,437,796
Fixed maturities, trading, amortized cost	14,221	14,221
Equity securities, at cost	5,065	5,139
Commercial mortgage and other loans, allowance for credit losses	457	165
Other invested assets, at fair value	$ 37,189	$ 24,726
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized	400,000	400,000
Common stock, shares issued	400,000	400,000
Common stock, shares outstanding	400,000	400,000