Fair Value Measurements Fair Value Measurements (Details Textual) (Details) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended							3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2014 Maximum [Member]	Jun. 30, 2014 Minimum [Member]	Jun. 30, 2014 Outperformance (underperformance) of the underlying actively managed fund compared to indices [Member]	Jun. 30, 2013 Outperformance (underperformance) of the underlying actively managed fund compared to indices [Member]	Jun. 30, 2014 Outperformance (underperformance) of the underlying actively managed fund compared to indices [Member]	Jun. 30, 2013 Outperformance (underperformance) of the underlying actively managed fund compared to indices [Member]	Jun. 30, 2014 Credit standing adjustment assumption net of reinsurance [Member]	Jun. 30, 2013 Credit standing adjustment assumption net of reinsurance [Member]	Jun. 30, 2014 Credit standing adjustment assumption net of reinsurance [Member]	Jun. 30, 2013 Credit standing adjustment assumption net of reinsurance [Member]	Jun. 30, 2014 Policyholder Behavior Assumptions [Member]	Jun. 30, 2014 Derivative Liabilities [Member]	Dec. 31, 2013 Derivative Liabilities [Member]	Jun. 30, 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]	Jun. 30, 2014 US Treasury Securities [Member]	Jun. 30, 2013 US Treasury Securities [Member]	Jun. 30, 2014 US Treasury Securities [Member]	Jun. 30, 2013 US Treasury Securities [Member]
Derivative [Line Items]
Fair Value, Assets Level One To Level Two Transfers, Amount																			$ 309,000,000	$ 350,000,000	$ 1,600,000,000	$ 466,000,000
Adjustments to Broker Prices Received	0		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Based on Inputs																	0	108,000,000
Pre-tax realized gains	(107,000,000)	(111,000,000)				7,000,000	0	20,000,000	8,000,000	2,000,000	(1,000,000)	1,000,000	(11,000,000)	0
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															$ 203,000,000	$ 128,000,000