Other Assets - Summary of Other Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2018	Sep. 30, 2018
Other Assets, Noncurrent [Abstract]
Investments in non-consolidated joint ventures	$ 112	$ 102
Asbestos-related recoveries (see Note 21)	60	76
Unamortized revolver debt issuance costs	6	7
Capitalized software costs, net	24	26
Deferred income tax assets, net	137	140
Assets for uncertain tax positions	51	53
Prepaid pension costs	154	152
Intangible assets	17	18
Other	33	22
Other assets	594	596
Finite-Lived Intangible Assets [Line Items]
Intangible assets	17	18
Customer Relationships
Other Assets, Noncurrent [Abstract]
Intangible assets	22	22
Finite-Lived Intangible Assets [Line Items]
Intangible assets	22	22
Accumulated amortization	$ 5	$ 4
Weighted average amortization period	19 years