Significant Accounting Policies (Details 3) (Consolidated Legg Mason, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Consolidated Legg Mason
Balance, beginning of period	$ 24,031	$ 36,712	$ 29,577
Net income (loss) attributable to redeemable noncontrolling interests	971	8,915	5,584
Net (redemptions/distributions paid to)/subscriptions received from noncontrolling interest holders	(3,993)	(21,596)	1,551
Balance, end of period	$ 21,009	$ 24,031	$ 36,712