Subsequent Event Subsequent Event - Precidian Investments Acquisition (Details) - Consolidated Legg Mason, Inc. - Subsequent Event [Member]	Jan. 22, 2016
Subsequent Event [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	19.90%
Scenario, Forecast [Member]
Subsequent Event [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	75.00%

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

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Period Type:	duration