Discontinued Operations - Reconciliation of Consolidated Income (Loss) From Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Income (loss) from discontinued operations attributable to Composites/Marl facility
Income from discontinued operations	$ (7)	$ 31	$ (9)	$ 54
Composites/Marl facility [Member]
Income (loss) from discontinued operations attributable to Composites/Marl facility
Sales	17	284	28	559
Cost of sales	(10)	(217)	(19)	(434)
Selling, general and administrative expense	(2)	(19)	(4)	(41)
Research and development expense		(3)		(6)
Equity and other income			2	3
Pretax operating income of discontinued operations	5	45	7	81
Net interest and other financing expense		(6)		(12)
Pretax income of discontinued operations	5	39	7	69
Income tax expense	(1)	(11)	(3)	(16)
Income from discontinued operations	$ 4	$ 28	$ 4	$ 53

Disposal group, including discontinued operation, equity and other income (expense).

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Disposal group including discontinued operation, interest and other financing income (expense).

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Disposal group including discontinued operation research and development expense.

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Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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Amount of costs of goods sold attributable to disposal group, including, but not limited to, discontinued operation.

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Amount of operating income (loss) attributable to disposal group, including, but not limited to, discontinued operation.

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Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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