Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Supplemental Cash Flow Information [Abstract]
Non-cash modifications of certain mortgage loans, fixed income securities, limited partnership interests and other investments, as well as mergers completed with equity securities	$ 270	$ 54
Non-cash financing activities related to the issuance of shares for vested restricted stock units	39	72
Debt acquired	34
Net change in proceeds managed
Net change in short-term investments	(56)	34
Operating cash flow (used) provided	(56)	34
Net change in cash	0	(3)
Net change in proceeds managed	(56)	31
Change in Liabilities for Collateral [Roll Forward]
Liabilities for collateral, beginning of period	(840)	(782)
Liabilities for collateral, end of period	(896)	(751)
Operating cash flow provided (used)	$ 56	$ (31)