Supplemental Guarantor Condensed Consolidating Financial Statements (Details 3) (USD $) In Millions, unless otherwise specified	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014
CASH FLOWS PROVIDED BY (USED FOR) OPERATING ACTIVITIES	$ 29	$ 18
INVESTING ACTIVITIES
Capital expenditures	(23)	(25)
Net investing cash flows provided by discontinued operations	4	3
CASH USED FOR INVESTING ACTIVITIES	(19)	(22)
FINANCING ACTIVITIES
Repayment of notes and term loan	(16)us-gaap_RepaymentsOfNotesPayable	(308)us-gaap_RepaymentsOfNotesPayable
Proceeds from debt issuance	0	225
Debt issuance costs	0us-gaap_PaymentsOfDebtIssuanceCosts	(9)us-gaap_PaymentsOfDebtIssuanceCosts
Repurchase of common stock	(16)	0
Debt issuance costs	0mtor_IntercompanyAdvances	0mtor_IntercompanyAdvances
Other financing activities	(6)	13
CASH USED FOR FINANCING ACTIVITIES	(38)	(79)
EFFECT OF CHANGES IN FOREIGN CURRENCY EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	(12)	(2)
CHANGE IN CASH AND CASH EQUIVALENTS	(40)	(85)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	247	318
CASH AND CASH EQUIVALENTS AT END OF PERIOD	207	233
Parent
CASH FLOWS PROVIDED BY (USED FOR) OPERATING ACTIVITIES	7	(30)
INVESTING ACTIVITIES
Capital expenditures	(1)	(2)
Net investing cash flows provided by discontinued operations	0	0
CASH USED FOR INVESTING ACTIVITIES	(1)	(2)
FINANCING ACTIVITIES
Repayment of notes and term loan	(16)	(308)
Proceeds from debt issuance		225
Debt issuance costs		(9)
Repurchase of common stock	(16)
Debt issuance costs	54	92
Other financing activities	0	0
CASH USED FOR FINANCING ACTIVITIES	22	0
EFFECT OF CHANGES IN FOREIGN CURRENCY EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	0	0
CHANGE IN CASH AND CASH EQUIVALENTS	28	(32)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	71	144
CASH AND CASH EQUIVALENTS AT END OF PERIOD	99	112
Guarantors
CASH FLOWS PROVIDED BY (USED FOR) OPERATING ACTIVITIES	10	8
INVESTING ACTIVITIES
Capital expenditures	(10)	(11)
Net investing cash flows provided by discontinued operations	1	0
CASH USED FOR INVESTING ACTIVITIES	(9)	(11)
FINANCING ACTIVITIES
Repayment of notes and term loan	0	0
Proceeds from debt issuance		0
Debt issuance costs		0
Debt issuance costs	0	0
Other financing activities	(2)	0
CASH USED FOR FINANCING ACTIVITIES	(2)	0
EFFECT OF CHANGES IN FOREIGN CURRENCY EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	0	0
CHANGE IN CASH AND CASH EQUIVALENTS	(1)	(3)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	5	6
CASH AND CASH EQUIVALENTS AT END OF PERIOD	4	3
Non-Guarantors
CASH FLOWS PROVIDED BY (USED FOR) OPERATING ACTIVITIES	12	40
INVESTING ACTIVITIES
Capital expenditures	(12)	(12)
Net investing cash flows provided by discontinued operations	3	3
CASH USED FOR INVESTING ACTIVITIES	(9)	(9)
FINANCING ACTIVITIES
Repayment of notes and term loan	0	0
Proceeds from debt issuance		0
Debt issuance costs		0
Debt issuance costs	(54)	(92)
Other financing activities	(4)	13
CASH USED FOR FINANCING ACTIVITIES	(58)	(79)
EFFECT OF CHANGES IN FOREIGN CURRENCY EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	(12)	(2)
CHANGE IN CASH AND CASH EQUIVALENTS	(67)	(50)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	171	168
CASH AND CASH EQUIVALENTS AT END OF PERIOD	104	118
Elims
CASH FLOWS PROVIDED BY (USED FOR) OPERATING ACTIVITIES	0	0
INVESTING ACTIVITIES
Capital expenditures	0	0
Net investing cash flows provided by discontinued operations	0	0
CASH USED FOR INVESTING ACTIVITIES	0	0
FINANCING ACTIVITIES
Repayment of notes and term loan	0	0
Proceeds from debt issuance		0
Debt issuance costs		0
Debt issuance costs	0	0
Other financing activities	0	0
CASH USED FOR FINANCING ACTIVITIES	0	0
EFFECT OF CHANGES IN FOREIGN CURRENCY EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	0	0
CHANGE IN CASH AND CASH EQUIVALENTS	0	0
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	0	0
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 0	$ 0

The cash inflow (outflow) associated with intercompany transactions.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.

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Amount of cash inflow (outflow) of investing activities of discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Amount of increase (decrease) from the effect of exchange rate changes on cash and cash equivalent balances held in foreign currencies.

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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The cash outflow to reacquire common stock during the period.

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The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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The net cash inflow or outflow from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.

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The cash outflow for a borrowing supported by a written promise to pay an obligation.

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