Commitments and Contingent Liabilities Commitments and Contingent Liabilities (Commitments to Fund Investments) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Limited Partner [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 272	$ 239
Commercial Loan [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	27	5
Private Placement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	8	22
Bank Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 59	$ 37