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

Unobservable Inputs [Abstract]

No definition available.

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=35744584&loc=d3e6927-128479

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.