Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Apr. 26, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Non-cash modifications of certain mortgage loans, fixed income securities, limited partnerships and other investments, as well as mergers completed with equity securities	$ 99	$ 42
Liabilities assumed	34
Net change in proceeds managed
Net change in short-term investments	(45)	45
Operating cash flow (used) provided	(45)	45
Change in Liabilities for Collateral
Liabilities for collateral, beginning of period	(550)	(510)
Liabilities for collateral, end of period	(595)	(465)
Operating cash flow provided (used)	45	$ (45)
Notes issued	$ 325			$ 275
Kennett Capital Inc | Subsidiary Issuer | Surplus Notes Due 2036 at 4.14 Percent
Change in Liabilities for Collateral
Notes issued			$ 50