Comprehensive Income - Schedule of Accumulated Other Comprehensive Loss (Detail) $ in Millions	3 Months Ended
	Dec. 31, 2019 USD ($)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ (269)
Other comprehensive income	10
Ending balance	(169)
Foreign Currency Translation Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(218)
Other comprehensive income	7
Ending balance	(211)
Minimum Pension Liability Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(14)
Other comprehensive income	0
Ending balance	(14)
Deferred Gains (Losses) On Derivative Financial Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(8)
Other comprehensive income	3
Ending balance	(5)
Accumulated Other Comprehensive Loss, net
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(240)
Ending balance	$ (230)