Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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	$ 102	$ 306	$ 231
Liabilities for collateral received reported in other liabilities and accrued expenses	508	322	543
Obligations to return cash collateral for over-the-counter ("OTC") derivatives reported in other liabilities and accrued expenses or other investments	2	6	18
Net change in proceeds managed
Net change in short-term investments	(182)	235	(298)
Operating cash flow (used) provided	(182)	235	(298)
Net change in cash	0	(2)	0
Net change in proceeds managed	(182)	233	(298)
Net change in liabilities
Liabilities for collateral, beginning of year	(328)	(561)	(263)
Liabilities for collateral, end of year	(510)	(328)	(561)
Operating cash flow provided (used)	$ 182	$ (233)	$ 298