Consolidation and Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Decrease to deferred federal income tax liability	$ (55,428)		$ (55,428)		$ (36,767)
Decrease to retained earnings	(2,057,889)		(2,057,889)		(2,014,570)
Other net investment gains (losses)	3,125	$ 5,477	6,610	$ 10,106
Net OTTI losses recognized in earnings	0	(5,902)	0	(5,902)
Earnings (loss) before Federal income taxes	60,558	42,144	57,579	92,735
Federal income taxes	12,145	8,448	11,228	18,841
Net earnings (loss)	48,413	33,696	46,351	73,894
Unrealized Gains and Losses on Available-for-sale Securities | Amount Reclassified From Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net investment gains (losses)	1,729	1,168	2,491	2,267
Net OTTI losses recognized in earnings	0	(5,902)	0	(5,902)
Earnings (loss) before Federal income taxes	1,729	(4,734)	2,491	(3,635)
Federal income taxes	363	(994)	523	(763)
Net earnings (loss)	$ 1,366	$ (3,740)	$ 1,968	$ (2,872)
Restatement Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Increase in future policy benefits liability					15,000
Decrease to deferred federal income tax liability					3,200
Decrease to retained earnings					$ 11,800