Investments (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Securities	Jun. 30, 2012	Jun. 30, 2013 Residential Mortgage Backed Securities [Member]	Dec. 31, 2012 Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Non-credit related portion of other-than-temporary impairment charges taken for securities still owned					$ 227	$ 227
Gross unrealized losses on fixed maturities	(215)		(215)		(45)	(54)
Investments (Textual) [Abstract]
Number of available for sale fixed maturities in an unrealized loss position			1,000
Percentage (based on amount of unrealized loss) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade			79.00%
Percentage (based on fair value) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade			85.00%
Average life of ABS			4 years 6 months
Average life of MBS			3 years 6 months
Percentage increase in shareholders' equity			10.00%
Realized gain (loss) from the mark-to-market of certain MBS	$ (3)	$ (1)	$ (1)	$ 3