Name:	ment_BusinessCombinationContingentConsiderationDiscountRateRangeOfOutcomesValueHigh
Namespace Prefix:	ment_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

For contingent consideration arrangements recognized in connection with a business combination, this element represents the low end of the range of discount rates used to determine the fair value of the contingent consideration.

No definition available.

Name:	ment_BusinessCombinationContingentConsiderationDiscountRateRangeOfOutcomesValueLow
Namespace Prefix:	ment_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

For contingent consideration arrangements recognized in connection with a business combination, this element represents the high end of the timing of cash flows to be paid under the arrangement.

No definition available.

Name:	ment_BusinessCombinationContingentConsiderationTimingOfCashFlowsRangeOfOutcomesValueHigh
Namespace Prefix:	ment_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

For contingent consideration arrangements recognized in connection with a business combination, this element represents the low end of the timing of cash flows to be paid under the arrangement.

No definition available.

Name:	ment_BusinessCombinationContingentConsiderationTimingOfCashFlowsRangeOfOutcomesValueLow
Namespace Prefix:	ment_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ment_UnobservableInputsAbstract
Namespace Prefix:	ment_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph g

-Clause 3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Name:	us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

For contingent consideration arrangements and indemnification assets recognized in connection with a business combination, this element represents an estimate of the low-end of the potential range (undiscounted) of the consideration which may be paid.