Name:	lm_DefinedContributionPlanEmployerContributionMatchingPercentOfEligibleCompensation
Namespace Prefix:	lm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

This element represents the maximum percentage of employee contributions up to a specified percentage of compensation that will be matched by the employer.

No definition available.

Name:	lm_DefinedContributionPlanEmployerContributionMatchingPercentOfEmployeeContribution
Namespace Prefix:	lm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the amount of maximum contribution made by employer under defined contribution plan per year.

No definition available.

Name:	lm_DefinedContributionPlanMaximumEmployerContribution
Namespace Prefix:	lm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	lm_EmployeeBenefitsAbstract
Namespace Prefix:	lm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the number of types of discretionary contributions.

No definition available.

Name:	lm_NumberOfTypesOfDiscretionaryContributions
Namespace Prefix:	lm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The amount of the cost recognized during the period for defined contribution plans.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942