Consolidated Statements of Comprehensive Income (Loss) (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)	$ (359,748)	$ 231,031	$ 245,763
Other comprehensive income (loss):
Foreign currency translation adjustment	(23,945)	(22,098)	35,159
Unrealized gains (losses) on investment securities:
Unrealized holding gains (losses), net of tax provision (benefit) of $(1), $132, and $(22), respectively	(1)	198	(33)
Reclassification adjustment for (gains) losses included in net income (loss)	13	11	8
Net unrealized gains (losses) on investment securities	12	209	(25)
Total other comprehensive income (loss)	(23,933)	(21,889)	35,134
Comprehensive Income (Loss)	(383,681)	209,142	280,897
Less: Comprehensive income (loss) attributable to noncontrolling interests	(6,421)	10,214	(8,160)
Comprehensive Income (Loss) Attributable to Legg Mason, Inc.	$ (377,260)	$ 198,928	$ 289,057