Deferred Policy Acquisition Costs, Value of Business Acquired and Other Policy-Related Intangibles (DAC and VOBA) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net [Abstract]
Beginning Balance of DAC	$ 4,518	$ 5,015	$ 5,667
Capitalizations of DAC	365	319	256
Net investment gains (losses) of DAC and net derivative gains (losses) of DAC	220	(370)	127
Other expenses of DAC	(586)	(535)	(958)
Total amortization of DAC	(366)	(905)	(831)
Unrealized investment gains (losses) of DAC	(190)	89	(77)
Ending Balance of DAC	4,327	4,518	5,015
Beginning Balance of VOBA	568	608	672
Net investment gains (losses) of VOBA and net derivative gains (losses) of VOBA	(1)	(1)	(9)
Other expenses of VOBA	(28)	(105)	(76)
Total amortization of VOBA	(29)	(106)	(85)
Unrealized investment gains (losses) of VOBA	(57)	66	21
Ending Balance of VOBA	482	568	608
Ending Balance of DAC and VOBA	$ 4,809	$ 5,086	$ 5,623