Certain Long-Duration Contracts with Guarantees (Liabilities for Guarantee Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	$ 23,179,710	$ 16,407,407	$ 11,249,071
Incurred guarantee benefits	(3,104,965)	6,185,375	4,469,472
Paid guarantee benefits	(213,847)	(165,619)	(138,843)
Change in unrealized investment gains and losses	(373,154)	752,547	827,707
Ending balance	19,487,744	23,179,710	16,407,407
GMDB | Annuity Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	569,063	460,501	411,568
Incurred guarantee benefits	(10,596)	114,878	52,717
Paid guarantee benefits	(24,394)	(37,804)	(25,992)
Change in unrealized investment gains and losses	(46,542)	31,488	22,208
Ending balance	487,531	569,063	460,501
GMDB | Variable Life, Variable Universal Life & Universal Life
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	9,363,585	7,400,233	5,231,854
Incurred guarantee benefits	1,089,139	1,368,759	1,473,762
Paid guarantee benefits	(189,453)	(126,148)	(110,642)
Change in unrealized investment gains and losses	(326,128)	720,741	805,259
Ending balance	9,937,143	9,363,585	7,400,233
GMIB | Annuity Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	19,248	17,107	16,810
Incurred guarantee benefits	(3,650)	3,490	2,266
Paid guarantee benefits	0	(1,667)	(2,209)
Change in unrealized investment gains and losses	(484)	318	240
Ending balance	15,114	19,248	17,107
GMWB/GMIWB/ GMAB | Annuity Contracts
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning balance	13,227,814	8,529,566	5,588,839
Incurred guarantee benefits	(4,179,858)	4,698,248	2,940,727
Paid guarantee benefits	0	0	0
Change in unrealized investment gains and losses	0	0	0
Ending balance	$ 9,047,956	$ 13,227,814	$ 8,529,566