Significant Accounting Policies (Details 6) (Consolidated Legg Mason [Domain], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Consolidated Legg Mason [Domain]
Balance, beginning of period			$ 24,031	$ 36,713
Net income (loss) attributable to redeemable noncontrolling interests	350	(148)	168	8,119
Net (redemptions/distributions paid to)/subscriptions received from noncontrolling interest holders			(2,523)	(16,016)
Balance, end of period	$ 21,676	$ 28,816	$ 21,676	$ 28,816