Contingencies, Commitments and Guarantees (Commitments and Guarantees - Narrative) (Details) (USD $) In Billions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Commitments to Fund Partnership Investments, Bank Credit Facilities, Bridge Loans and Private Corporate Bond Investments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 6.3	$ 5.3
Mortgage Loan Commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 4.7	$ 4.0

The face amount of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant