Contingencies, Commitments and Guarantees (Commitments and Guarantees - Narrative) (Details) (USD $) In Billions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Commitments to Fund Partnership Investments, Bank Credit Facilities, Bridge Loans and Private Corporate Bond Investments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 4.7	$ 5.3
Mortgage Loan Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 2.8	$ 3.4