Reinsurance - Guaranteed Minimum Death Benefit Contracts, Future Policy Benefits (Details) - Variable Annuity [Member] - Guaranteed Minimum Death Benefit [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Activity in future policy benefits reserves for GMDB business [Line Items]
Future Policy Benefit Reserve, beginning balance, gross	$ 1,252	$ 1,270
Costs payable, beginning balance, gross	18	16
Less: Reinsurance and other amounts recoverable	1,164	1,186
Balance at January 1, net	106	100
Add: Incurred benefits	1	3
Less: Paid benefits	0	(3)
Ending balance, net	107	106
Costs payable, ending balance, gross	22	18
Add: Reinsurance and other amounts recoverable	1,201	1,164
Future Policy Benefit Reserve, ending balance, gross	$ 1,286	$ 1,252