Reinsurance (Income Statement Reinsurance Results) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Premiums:
Direct	$ 23,582	$ 26,272		$ 29,022
Assumed	16,093	37,806		31,570
Ceded	(3,102)	(3,493)		(1,042)
Net premiums	36,573	60,585		59,550
Policy charges and fee income:
Direct	438,869	409,331		477,478
Assumed	819,191	1,564,776		1,638,023
Ceded	(26,244)	(30,508)		(34,455)
Net policy charges and fee income	1,231,816	1,943,599		2,081,046
Asset management and service fees:
Direct	97,984	90,658		97,887
Assumed	165,177	308,272		306,892
Ceded	(8,411)	(8,003)		(8,346)
Insurance Agency Management Fee	254,750	390,927	[1]	396,433	[1]
Realized investment gains (losses), net:
Direct	(4,688,812)	(2,208,057)		(1,137,422)
Assumed	12,350,170	(3,131,107)		(1,584,764)
Ceded	(172,551)	78,224		40,866
Realized investment gains (losses), net	7,488,807	(5,260,940)		(2,681,320)
Policyholders' benefits (including change in reserves):
Direct	49,377	72,467		58,308
Assumed	(253,812)	156,320		89,284
Ceded	15,548	6,175		3,667
Net policyholders' benefits (including change in reserves)	(219,983)	222,612		143,925
Interest credited to policyholders’ account balances:
Direct	175,053	85,454		82,444
Assumed	476,408	97,373		84,182
Ceded	(11,829)	(2,667)		(5,417)
Net interest credited to policyholders’ account balances	639,632	180,160		161,209
Reinsurance expense allowances and general and administrative expenses, net of capitalization and amortization	1,694,472	1,036,119		988,951
Unaffiliated activity
Policy charges and fee income:
Ceded	(400)	(2,600)		(1,000)
Policyholders' benefits (including change in reserves):
Ceded	$ 13,800	$ (100)		$ 100

[1] Prior period amounts have been reclassified to conform to current period presentation.