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, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net [Abstract]
Beginning Balance of DAC	$ 14,789	$ 13,830	$ 13,464
Capitalization of DAC	3,254	3,002	3,152
Net investment gains (losses) of DAC and net derivative gains (losses) of DAC	(109)	60	229
Other expenses of DAC	(2,599)	(2,426)	(2,555)
Total amortization of DAC	(2,708)	(2,366)	(2,326)
Unrealized investment gains (losses) of DAC	511	(525)	(171)
Effect of foreign currency translation and other of DAC	(276)	848	(289)
Ending Balance of DAC	15,570	14,789	13,830
Beginning Balance of VOBA	3,630	3,760	3,966
Net investment gains (losses) of VOBA and net derivative gains (losses) of VOBA	0	0	(3)
Other expenses of VOBA	(267)	(315)	(389)
Total amortization of VOBA	(267)	(315)	(392)
Unrealized investment gains (losses) of VOBA	10	(4)	8
Effect of foreign currency translation and other of VOBA	(48)	189	178
Ending Balance of VOBA	3,325	3,630	3,760
Balance at December 31,	$ 18,895	$ 18,419	$ 17,590