Income Taxes (Details 4) (Consolidated Legg Mason, USD $) In Thousands, unless otherwise specified	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Consolidated Legg Mason
Income Taxes
Unrecognized tax benefits that would favorably impact tax provision and rate, if recognized	$ 46,340	$ 62,400	$ 53,500
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities and the Lapse of Applicable Statutes of Limitations	16,842
Reconciliation of the beginning and ending amount of unrecognized gross tax benefits
Balance, beginning of year	90,831	77,653	51,027
Additions based on tax positions related to the current year	11,726	9,822	1,361
Additions for tax positions of prior years	8,439	10,668	34,959
Reductions for tax positions of prior years	(13,083)	(3,575)	(6,107)
Decreases related to settlements with taxing authorities	(25,205)	(3,185)	(2,667)
Expiration of statutes of limitations	(58)	(552)	(920)
Balance, end of year	72,650	90,831	77,653
Amount remaining of earnings from foreign subsidiaries to be repatriated	$ 325,000

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Decrease in unrecognized tax benefits resulting from settlements with taxing authorities and the lapse of applicable statutes of limitations.

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The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.

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The gross amount of decreases in unrecognized tax benefits resulting from tax positions taken in prior period tax returns, excluding amounts pertaining to examined tax returns.

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The gross amount of decreases in unrecognized tax benefits resulting from settlements with taxing authorities.

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The gross amount of increases in unrecognized tax benefits resulting from tax positions that have been or will be taken in the tax return for the current period, excluding amounts pertaining to examined tax returns.

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The gross amount of increases in unrecognized tax benefits resulting from tax positions taken in prior period tax returns, excluding amounts pertaining to examined tax returns.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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