Reinsurance (Reinsurance amounts included in the Statements of Operations and Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Premiums:
Direct	$ 8,944	$ 6,137
Assumed	0	10,076
Ceded	(1,393)	(451)
Net premiums	7,551	15,762
Policy charges and fee income:
Direct	102,008	107,332
Assumed	0	407,138
Ceded	(5,164)	(6,887)
Net policy charges and fee income	96,844	507,583
Asset management and service fees:
Direct	22,256	23,916
Assumed	0	81,622
Ceded	(1,915)	(2,017)
Net asset management and service fees	20,341	103,521
Realized investment gains (losses), net:
Direct	312,198	(2,106,085)
Assumed	0	5,377,897
Ceded	168,727	(142,676)
Realized investment gains (losses), net	480,925	3,129,136
Policyholders' benefits (including change in reserves):
Direct	31,145	17,289
Assumed	0	12,390
Ceded	(4,891)	(51)
Net policyholders' benefits (including change in reserves)	26,254	29,628
Interest credited to policyholders’ account balances:
Direct	91,152	81,621
Assumed	0	70,946
Ceded	(6,509)	(4,657)
Net interest credited to policyholders’ account balances	84,643	147,910
Reinsurance expense allowances and general and administrative expenses, net of capitalization and amortization	(41,108)	339,711
Unaffiliated activity
Policy charges and fee income:
Ceded	0	(300)
Policyholders' benefits (including change in reserves):
Ceded	$ 0	$ (100)