Reinsurance (Effects of Reinsurance on Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premiums:
Direct premiums	$ 1,640	$ 1,731	$ 2,226
Reinsurance assumed	12	13	81
Reinsurance ceded	(783)	(916)	(1,127)
Net premiums	869	828	1,180
Direct universal life and investment-type product policy fees	3,617	3,653	3,582
Reinsurance assumed	101	103	126
Reinsurance ceded	(528)	(600)	(611)
Net universal life and investment-type product policy fees	3,190	3,156	3,097
Other revenues:
Direct other revenues	262	260	271
Reinsurance assumed	2	29	89
Reinsurance ceded	23	47	349
Net other revenues	287	336	709
Policyholder benefits and claims:
Direct policyholder benefits and claims	4,724	5,080	6,101
Reinsurance assumed	75	89	127
Reinsurance ceded	(1,619)	(1,575)	(2,490)
Net policyholder benefits and claims	3,180	3,594	3,738
Amortization of deferred policy acquisition costs and value of business acquired
Direct amortization of deferred policy acquisition costs and value of business acquired	$ 1,011	$ 916	$ (225)