Name:	ment_AccruedSpecialCharges
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of cash paid or adjustments made in the period to fully or partially settle a specified, previously accrued cost including employee terminations, expenses related to certain litigation, expenses incurred related to acquisitions, excess facility costs, and other asset related charges.

No definition available.

Name:	ment_AccruedSpecialChargesSettled
Namespace Prefix:	ment_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The charge against earnings in the period, comprised of costs associated with restructuring activities not otherwise defined in the taxonomy, excluding a discounted operation as defined by generally accepted accounting principles.

No definition available.

Name:	ment_OtherCharges
Namespace Prefix:	ment_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The charge against earnings in the period related to litigation, comprised of costs not otherwise defined in the taxonomy, excluding a discounted operation as defined by generally accepted accounting principles.

No definition available.

Name:	ment_OtherChargesLitigation
Namespace Prefix:	ment_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of expenses associated with special charges including employee terminations, expenses related to certain litigation, expenses incurred related to acquisitions, excess facility costs, and other asset related charges. Excludes expenses related to a discontinued operation or an asset retirement obligation.

No definition available.

Name:	ment_SpecialCharges
Namespace Prefix:	ment_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RestructuringCostAndReserveLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RestructuringReserveRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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

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