Reinsurance (Income Statement Reinsurance Results) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Premiums:
Direct	$ 1,909,878	$ 1,923,708	$ 1,882,584
Assumed	162	184	206
Ceded	(1,706,364)	(1,831,716)	(1,854,246)
Net premiums	203,676	92,176	28,544
Policy charges and fee income:
Direct	3,647,883	3,491,735	3,725,113
Assumed	582,003	587,466	519,265
Ceded	(2,700,129)	(3,454,881)	(3,700,222)
Net policy charges and fee income	1,529,757	624,320	544,156
Net investment income:
Direct	555,404	372,822	398,762
Assumed	1,049	1,579	1,631
Ceded	(6,218)	(7,051)	(6,596)
Net investment income	550,235	367,350	393,797
Asset administration fees:
Direct	403,359	360,438	355,118
Assumed	0	0	0
Ceded	(201,182)	(341,300)	(339,062)
Net asset administration fees	202,177	19,138	16,056
Other income:
Direct	227,035	78,445	83,891
Assumed	(66)	(1)	(293)
Ceded	35,790	165	(59)
Amortization of reinsurance income	4,449	4,647	21
Net other income	267,208	83,256	83,560
Realized investment gains (losses), net:
Direct	7,656,388	(3,593,799)	(1,912,241)
Assumed	18,171	0	0
Ceded	(12,969,965)	3,530,823	1,795,492
Realized investment gains (losses), net	(5,295,406)	(62,976)	(116,749)
Policyholders’ benefits (including change in reserves):
Direct	3,611,402	3,584,011	3,352,159
Assumed	849,599	1,055,277	885,542
Ceded	(3,805,091)	(4,341,139)	(4,084,627)
Net policyholders’ benefits (including change in reserves)	655,910	298,149	153,074
Interest credited to policyholders’ account balances:
Direct	563,821	536,886	470,551
Assumed	138,202	136,153	135,355
Ceded	(816,608)	(439,664)	(418,677)
Net interest credited to policyholders’ account balances	(114,585)	233,375	187,229
Net reinsurance expense allowances, net of capitalization and amortization	(2,265,350)	(1,589,113)	(1,772,111)
Unaffiliated
Premiums:
Assumed	200	200	200
Ceded	(19,800)	(10,500)	(600)
Policy charges and fee income:
Ceded	(65,000)	(54,000)	(34,000)
Other income:
Assumed	0	0	(300)
Realized investment gains (losses), net:
Ceded	(48,000)	73,000	44,000
Policyholders’ benefits (including change in reserves):
Assumed	400	900	1,900
Ceded	$ (201,000)	$ (70,000)	$ (30,000)