Other Assets - Summary of other assets (Details) - USD ($) $ in Millions	Mar. 31, 2017	Sep. 30, 2016
Other Assets, Noncurrent [Abstract]
Investments in non-consolidated joint ventures	$ 106	$ 100
Asbestos-related recoveries (see Note 21)	46	49
Unamortized revolver debt issuance costs	9	7
Capitalized software costs, net	28	29
Non-current deferred income tax assets, net	401	413
Assets for uncertain tax positions	36	35
Prepaid pension costs	129	123
Other	6	4
Other assets	$ 761	$ 760