Deferred Policy Acquisition Costs, Value of Business Acquired and Other Policy-Related Intangibles (VODA and VOCRA) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Insurance [Abstract]
Balance at January 1,	$ 335	$ 384	$ 459
Acquisitions (1)	814	0	0
Amortization	(41)	(42)	(47)
Effect of foreign currency translation	(9)	(7)	(28)
Balance at December 31,	1,099	335	384
Accumulated amortization	$ 475	$ 434	$ 392