Reinsurance (Effects of Reinsurance on Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Premiums:
Direct premiums	$ 1,509	$ 1,651	$ 1,699
Reinsurance assumed	10	10	11
Reinsurance ceded	(753)	(779)	(810)
Net premiums	766	882	900
Universal life and investment-type product policy fees [Abstract]
Direct universal life and investment-type product policy fees	4,022	4,048	4,296
Reinsurance assumed	48	72	95
Reinsurance ceded	(607)	(540)	(556)
Net universal life and investment-type product policy fees	3,463	3,580	3,835
Other revenues
Other Income Direct	351	366	373
Commissions Fees And Other Income Assumed	16	1	0
Other Income Ceded	46	22	24
Other adjustments to net income (loss)	413	389	397
Policyholder benefits and claims:
Direct policyholder benefits and claims	7,545	5,441	4,891
Reinsurance assumed	103	36	32
Reinsurance ceded	(1,937)	(1,807)	(1,651)
Net policyholder benefits and claims	$ 5,711	$ 3,670	$ 3,272