Significant Accounting Policies (Details 2) (Legg Mason, Inc., USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Legg Mason, Inc.
Balance, beginning of period	$ 21,009	$ 24,031
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest	882	(661)
Net (redemptions/distributions paid to)/subscriptions received from noncontrolling interest holders	(1,409)	(1,868)
Balance, end of period	$ 20,482	$ 21,502
Future Growth Participation Rate	15.00%
Annual vesting percentage	20.00%
Vesting period	5 years