CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturities at fair value, amortized cost	$ 54,367,022	$ 54,466,305
Fixed maturities at amortized cost, fair value	2,594,441	2,547,210
Equity securities, cost	619,483	627,087
Mortgage loans, related to securitizations	17	134
Investment real estate, accumulated depreciation	283	251
Other intangibles, accumulated amortization	211,899	197,583
Property and equipment, accumulated depreciation	$ 37,450	$ 33,199
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized (in shares)	5,000	5,000
Common Stock, shares issued (in shares)	1,000	1,000
Net unrealized gains (losses) on investments, income tax	$ (67,182)	$ (368,830)
Net unrealized (losses) gains relating to other-than-temporary impaired investments for which a portion has been recognized in earnings, income tax	(3,717)	(6,054)
Accumulated loss - derivatives, income tax	(466)	(2)
Postretirement benefits liability adjustment, income tax	$ (4,112)	$ (4,112)