Fair Value Measurements Level 4 Fair Value Option (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value of assets and liabilities accounted for using the fair value option	$ (5)	$ 9	$ 31	$ (86)
Fair value of assets accounted for using fair value option	299		299		791
Asset-backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	13		13		3
Corporate Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value of assets and liabilities accounted for using the fair value option	(5)	1	(2)	(12)
Fair value of assets accounted for using fair value option	98		98		84
Collateralized Debt Obligations [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value of assets and liabilities accounted for using the fair value option	1	0	17	3
Fair value of assets accounted for using fair value option	78		78		167
Commercial Mortgage Backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	15		15		8
Foreign Government Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value of assets and liabilities accounted for using the fair value option	0	8	16	(77)
Fair value of assets accounted for using fair value option	4		4		494
Municipal Bonds [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	2		2		1
Residential Mortgage Backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Changes in fair value of assets and liabilities accounted for using the fair value option	(1)	0	0	0
Fair value of assets accounted for using fair value option	87		87		9
US Treasury and Government [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	$ 2		$ 2		$ 25