Leases - Schedule of Maturities of Lease Obligations (Detail) $ in Millions	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating Leases, 2019	$ 206
Operating Leases, 2020	183
Operating Leases, 2021	70
Operating Leases, 2022	64
Operating Leases, 2023	64
Operating Leases, Remaining years	198
Total lease payments	785
Less: Imputed interest	(77)
Total lease obligations	708
Financing Leases, 2019	18
Financing Leases, 2020	36
Financing Leases, 2021	36
Financing Leases, 2022	36
Financing Leases, 2023	36
Financing Leases, Remaining years	248
Total lease payments	410
Less: Imputed interest	(148)
Total lease obligations	$ 262