Significant Accounting Policies (Details 3) (Consolidated Legg Mason, Inc., USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Consolidated Legg Mason, Inc.
Redeemable Noncontrolling Interest [Line Items]
Balance, beginning of period	$ 21,009	$ 24,031	$ 36,712
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest	1,881	971	8,915
Net (redemptions/distributions paid to)/subscriptions received from noncontrolling interest holders	20,438	(3,993)	(21,596)
Management equity plan interests	1,816	0	0
Balance, end of period	$ 45,144	$ 21,009	$ 24,031