GOODWILL (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
Nov. 12, 2012	Sep. 30, 2014 segment	Sep. 30, 2013 segment
Goodwill [Line Items]
Number of reportable segments	2	2	2
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 434	$ 433
Segment reorganization			0
Foreign currency translation		(3)	1
Goodwill, ending balance		431	434
Commercial Truck & Industrial [Member]
Goodwill [Line Items]
Number of reporting units		2
Goodwill [Roll Forward]
Goodwill, beginning balance		262	0
Segment reorganization			262
Foreign currency translation		(1)	0
Goodwill, ending balance		261	262
Commercial Truck & Industrial [Member] \| Defense Reporting Unit [Member]
Goodwill [Roll Forward]
Goodwill, ending balance		20
Aftermarket & Trailer [Member]
Goodwill [Line Items]
Number of reporting units		1
Goodwill [Roll Forward]
Goodwill, beginning balance		172	171
Segment reorganization			0
Foreign currency translation		(2)	1
Goodwill, ending balance		170	172
Commercial Truck [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		0	153
Segment reorganization			(153)
Foreign currency translation		0	0
Goodwill, ending balance		0	0
Industrial [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		0	109
Segment reorganization			(109)
Foreign currency translation		0	0
Goodwill, ending balance		$ 0	$ 0

The increase (decrease) to the recorded value of goodwill for due to Segment Reorganization.

No definition available.

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Namespace Prefix:	mtor_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

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Period Type:	instant

- Details

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- Details

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- Definition

Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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