Leases - Balance sheet (Detail) $ in Millions	Mar. 31, 2019 USD ($)
Assets
Operating leases	$ 388
Operating right of use asset extensible list	us-gaap:OtherAssetsCurrent
Financing lease	$ 228
Financing Lease, right of use asset extensible list	us-gaap:PropertyPlantAndEquipmentNet
Total leased assets	$ 616
Liabilities
Operating, current	$ 85
Operating Lease, Liability current extensible list	us-gaap:AccruedLiabilitiesCurrent
Financing, current	$ 22
Financing Lease, Liability current extensible list	us-gaap:DebtCurrent
Operating, non current	$ 303
Operating lease, liability noncurrent extensible list	us-gaap:OtherLiabilitiesNoncurrent
Financing, non current	$ 185
Financing lease, liability noncurrent extensible list	us-gaap:LongTermDebtAndCapitalLeaseObligations
Total lease liabilities	$ 595