Short-Term Borrowings and Long-Term Debt (Details 3) (Legg Mason Group, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Legg Mason Group
Long-term debt
Remaining 2013	$ 0
2014	50,438
2015	50,439
2016	50,000
2017	50,000
Thereafter	950,000
Total	1,150,877
Long-term Debt, Fair Value	$ 1,201,642

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the remainder of the fiscal year following the latest fiscal year ended.

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