Consolidation and Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Decrease to deferred federal income tax liability	$ (53,055)		$ (53,055)		$ (36,767)
Decrease to retained earnings	(2,068,714)		(2,068,714)		(2,014,570)
Other net investment gains (losses)	6,050	$ 1,443	12,660	$ 11,549
Earnings before Federal income taxes	13,329	24,992	70,908	117,727
Federal income taxes	2,504	5,003	13,732	23,844
Net earnings	10,825	19,989	57,176	93,883
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)	889	198	3,380	2,465
Net OTTI losses recognized in earnings	0	(1,945)	0	(7,847)
Earnings before Federal income taxes	889	(1,747)	3,380	(5,382)
Federal income taxes	187	(367)	710	(1,130)
Net earnings	$ 702	$ (1,380)	$ 2,670	$ (4,252)
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