Debt and Other Obligations - Schedule of Future Years Payment (Detail) $ in Millions	Sep. 30, 2017 USD ($)
Debt Disclosure [Abstract]
2018	$ 255
2019	30
2022	365
Thereafter	258
Total	908
2018	3
2019	2
2020	2
2021	2
2022	2
Thereafter	9
Less: Interest	(7)
Total	13
2018	258
2019	32
2020	2
2021	2
2022	367
Thereafter	267
Total	$ 921