Reinsurance (Reinsurance amounts included in the Statement of Operations and Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Premiums:
Direct	$ 463,646	$ 487,010	$ 1,408,917	$ 1,459,895
Assumed	(2,653)	41	(10,730)	125
Ceded	(397,639)	(435,514)	(1,203,167)	(1,319,216)
Net premiums	63,354	51,537	195,020	140,804
Policy charges and fee income:
Direct	798,978	919,203	2,601,946	2,722,548
Assumed	153,387	146,257	465,580	432,907
Ceded	(513,584)	(455,359)	(1,811,371)	(2,213,289)
Net policy charges and fee income	438,781	610,101	1,256,155	942,166
Net investment income:
Direct	226,827	180,642	617,818	377,942
Assumed	349	(55)	1,167	675
Ceded	(16,414)	(1,477)	(36,795)	(5,340)
Net investment income	210,762	179,110	582,190	373,277
Asset administration fees:
Direct	84,959	101,105	271,071	296,542
Assumed	0	0	0	0
Ceded	(16,405)	(9,167)	(51,495)	(192,117)
Net asset administration fees	68,554	91,938	219,576	104,425
Other income (loss):
Direct	(181,634)	24,609	(855,885)	66,286
Assumed	3,059	(6)	550	(66)
Ceded	(2,925)	35,687	(3,363)	35,793
Amortization of reinsurance income	17,799	1,119	55,377	3,270
Net Other income (loss)	(163,701)	61,409	(803,321)	105,283
Realized investment gains (losses), net:
Direct	(4,646)	3,362,148	2,351,109	7,864,422
Assumed	122,365	0	(363,265)	0
Ceded	(93,761)	(8,370,760)	(465,070)	(12,918,928)
Realized investment gains (losses), net	23,958	(5,008,612)	1,522,774	(5,054,506)
Policyholders’ benefits (including change in reserves):
Direct	779,276	975,500	3,105,928	2,775,018
Assumed	267,428	222,418	1,267,705	639,927
Ceded	(924,565)	(811,915)	(3,873,624)	(2,856,953)
Net policyholders’ benefits (including change in reserves)	122,139	386,003	500,009	557,992
Interest credited to policyholders’ account balances:
Direct	267,194	150,269	672,034	430,494
Assumed	(52,300)	30,540	49,803	95,658
Ceded	(109,724)	(485,215)	(330,197)	(726,988)
Net interest credited to policyholders’ account balances	105,170	(304,406)	391,640	(200,836)
Reinsurance expense allowances and general and administrative expenses, net of capitalization and amortization	(107,471)	(1,398,529)	(323,553)	(2,159,809)
Unaffiliated activity
Premiums:
Assumed	(2,653)	41	(16,061)	125
Ceded	(9,581)	(6,089)	(25,274)	(19,739)
Policy charges and fee income:
Assumed	1,929	0	13,350	0
Ceded	(21,197)	(23,479)	(59,453)	(53,500)
Net investment income:
Ceded	(4,122)	0	195	0
Other income (loss):
Assumed	3,059	(8)	549	(68)
Realized investment gains (losses), net:
Assumed	122,365	0	(159,281)	0
Ceded	(575)	(9,800)	(14,340)	(119,980)
Policyholders’ benefits (including change in reserves):
Assumed	587	154	1,941	420
Ceded	(15,441)	(37,674)	(53,029)	(169,169)
Interest credited to policyholders’ account balances:
Assumed	$ (83,933)	$ 0	$ (86,713)	$ 0