Investments and Derivative Instruments Level 4 Other-Than-Temporary Impairment Losses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Other-Than-Temporary Impairment Losses [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	$ 12		$ 22
Other-Than-Temporary Impairment Losses [Roll Forward]
Balance as of beginning of period	(424)		(552)
Additions for credit impairments recognized on securities not previously impaired	(3)	[1]	(7)	[1]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses	0	[1]	11	[1]
Securities that matured or were sold during the period	4		33
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	2		0
Securities due to an increase in expected cash flows	9		6
Balance as of end of period	$ (412)		$ (531)

[1] These additions are included in the net OTTI losses recognized in earnings in the Condensed Consolidated Statements of Operations.