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, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Policy Acquisition Costs and Value of Business Acquired [Abstract]
Beginning Balance of DAC	$ 4,131	$ 4,162	$ 4,795
Capitalizations of DAC	282	325	279
Net investment gains (losses) of DAC and net derivative gains (losses) of DAC	1,348	188	(152)
Other expenses of DAC	(1,107)	(639)	(699)
Total amortization of DAC	241	(451)	(851)
Unrealized investment gains (losses) of DAC	(20)	95	(61)
Ending Balance of DAC	4,634	4,131	4,162
Beginning Balance of VOBA	678	728	896
Net investment gains (losses) of VOBA and net derivative gains (losses) of VOBA	2	(19)	(1)
Other expenses of VOBA	(71)	(125)	(138)
Total amortization of VOBA	(69)	(144)	(139)
Unrealized investment gains (losses) of VOBA	31	94	(29)
Ending Balance of VOBA	640	678	728
Balance at December 31,	$ 5,274	$ 4,809	$ 4,890