Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Supplemental Cash Flow Information [Abstract]
Non-cash modifications of certain mortgage loans, fixed income securities, limited partnerships and other investments, as well as mergers completed with equity securities	$ 2	$ 8
Liabilities assumed	34
Net change in proceeds managed
Net change in short-term investments	(29)	18
Operating cash flow (used) provided	(29)	18
Net change in liabilities
Liabilities for collateral, beginning of period	(550)	(510)
Liabilities for collateral, end of period	(579)	(492)
Operating cash flow provided (used)	$ 29	$ (18)