Investments and Derivative Instruments Level 4 Derivative Collateral Arrangements (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Derivative Collateral Arrangements [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 137,000,000		$ 120,000,000
Fair Value of Securities Received as Collateral that Can be Resold or Repledged	126,000,000		97,000,000
Securities Received as Collateral, Amount Repledged and Sold	0	0
Derivative Asset, Collateral, Obligation to Return Cash, Offset	477,000,000		327,000,000
Derivative, Collateral, Obligation to Return Securities	138,000,000		109,000,000
Fixed Maturities [Member]
Derivative Collateral Arrangements [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 1,100,000,000		$ 1,100,000,000