Other Financial Data Other Financial Data (Other Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Sep. 30, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Pension assets	$ 591	$ 197
Asbestos-related insurance receivables	124	133
Deferred income taxes	$ 74	$ 86