Accounts Payable, Accrued Liabilities and Other Liabilities - Components of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Payables And Accruals [Abstract]
Accounts payable	$ 339	$ 259
Accrued employee compensation	51	42
Other accrued liabilities	67	63
Total	$ 457	$ 364