Significant Accounting Policies (Details 2) (Consolidated Legg Mason, USD $) In Thousands, unless otherwise specified	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Consolidated Legg Mason
Net income (loss) attributable to noncontrolling interests
Net income (loss) attributable to redeemable noncontrolling interests	$ 971	$ 8,915	$ 5,584
Net income (loss) reclassified to appropriated retained earnings for consolidated investment vehicle	(7,392)	1,299	(13,744)
Total	$ (6,421)	$ 10,214	$ (8,160)

Amount of Net Income (Loss) attributable to noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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