Other Current Liabilities - Summary of other current liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016
Other Current Liabilities Disclosure [Abstract]
Compensation and benefits	$ 95	$ 115
Income taxes	3	8
Taxes other than income taxes	21	21
Accrued interest	14	14
Product warranties	16	18	$ 19
Environmental reserves (see Note 21)	7	7
Restructuring (see Note 7)	11	14	$ 6
Asbestos-related liabilities (see Note 21)	18	18
Indemnity obligations (see Note 21)	2	2
Other	58	51
Other current liabilities	$ 245	$ 268