Unaudited Interim Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, amortized cost	$ 5,468,161	$ 5,244,903
Fixed maturities, trading, amortized cost	44,759	44,759
Equity securities, cost	28,920	31,824
Other invested assets, at fair value	$ 88,109	$ 120,717
Common stock, par value (in dollars per share)	$ 10	$ 10
Common stock, shares authorized	1,000,000	1,000,000
Common stock, shares issued	250,000	250,000
Common stock, shares outstanding	250,000	250,000