Variable Interest Entities (Narrative) (Details) - USD ($)	Jun. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Principal Amount	$ 2,705,000,000	$ 2,705,000,000
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Fair value of assets held within unconsolidated VIEs	5,982,000,000	6,973,000,000
Fair value of liabilities held within unconsolidated VIEs	0	0
Other long-term investments | Net unrealized investment gains (losses)—all other
Variable Interest Entity [Line Items]
Maximum exposure to loss resulting from investment in unconsolidated VIEs	7,482,000,000	7,545,000,000
Available-for-sale | Other long-term investments | Fixed Maturities | Variable Interest Entity, Not Primary Beneficiary | Other trading account assets
Variable Interest Entity [Line Items]
Maximum exposure to loss resulting from investment in unconsolidated VIEs	$ 174,000,000	$ 137,000,000