Fair Value Measurements Fair Value Measurements (Details Textual) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Maximum [Member]	Mar. 31, 2014 Minimum [Member]	Mar. 31, 2014 Outperformance (underperformance) of the underlying actively managed fund compared to indices [Member]	Mar. 31, 2013 Outperformance (underperformance) of the underlying actively managed fund compared to indices [Member]	Mar. 31, 2014 Credit standing adjustment assumption net of reinsurance [Member]	Mar. 31, 2013 Credit standing adjustment assumption net of reinsurance [Member]	Mar. 31, 2014 Policyholder Behavior Assumptions [Member]	Mar. 31, 2013 Policyholder Behavior Assumptions [Member]	Mar. 31, 2014 Derivative Liabilities [Member]	Dec. 31, 2013 Derivative Liabilities [Member]	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Monthly N.A.V Calulation [Member] Limited Partnerships and Other Alternative Investments [Member] Alternative Assets [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Monthly N.A.V Calulation [Member] Limited Partnerships and Other Alternative Investments [Member] Alternative Assets [Member]
Derivative [Line Items]
Adjustments to Broker Prices Received	$ 0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Based on Inputs													0	108
Pre-tax realized gains	(80)	(432)			14	8	(1)	(10)	0	1
Daily analyses identify price			5.00%	3.00%
Percentage difference of sale trade price from prior days price				3.00%
Percentage difference of purchase trade price from current days price				3.00%
Percentage difference of weekly analyses identify price from published bond				5.00%
Percentage change of monthly analyses identify price				3.00%
Derivative Liability, Fair Value, Amount Offset Against Collateral											$ 114	$ 128