Reinsurance (Effects of Reinsurance on Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Premiums:
Direct premiums	$ 1,597	$ 1,640	$ 1,731
Reinsurance assumed	15	12	13
Reinsurance ceded	(765)	(783)	(916)
Net premiums	847	869	828
Universal life and investment-type product policy fees [Abstract]
Direct universal life and investment-type product policy fees	3,432	3,617	3,653
Reinsurance assumed	79	101	103
Reinsurance ceded	(529)	(528)	(600)
Net universal life and investment-type product policy fees	2,982	3,190	3,156
Other revenues:
Direct other revenues	244	262	260
Reinsurance assumed	3	2	29
Reinsurance ceded	19	23	47
Net other revenues	266	287	336
Policyholder benefits and claims:
Direct policyholder benefits and claims	5,267	4,724	5,080
Reinsurance assumed	70	75	89
Reinsurance ceded	(1,799)	(1,619)	(1,575)
Net policyholder benefits and claims	3,538	3,180	3,594
Other Expenses [Abstract]
Direct Other Expenses	1,839	1,812	1,835
Assumed Other Expenses	(10)	(4)	19
Ceded Other Expenses	(20)	(45)	(21)
Total other expenses	1,809	1,763	1,833
Amortization of deferred policy acquisition costs and value of business acquired
Direct amortization of deferred policy acquisition costs and value of business acquired	$ 395	$ 1,011	$ 916