Lease Liabilities Maturity (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months	$ 62
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Two	15
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Three	1
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Four	0
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Five	0
Lessee, Operating Lease, Liability, Payments, Due after Rolling Year Five	0
Lessee, Operating Lease, Liability, Payments, Due, Total	78
Operating Lease, Liability, Current	60	$ 0
Operating Lease, Liability, Noncurrent	16
Operating Lease, Liability, Total	76
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	2
Operating Lease, Right-of-Use Asset	76
Upstream Equipment [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months	44
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Two	5
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Three	0
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Four	0
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Five	0
Lessee, Operating Lease, Liability, Payments, Due after Rolling Year Five	0
Operating Lease, Liability, Current	43
Operating Lease, Liability, Noncurrent	5
Operating Lease, Liability, Total	48
Other Machinery and Equipment [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months	18
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Two	10
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Three	1
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Four	0
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Five	0
Lessee, Operating Lease, Liability, Payments, Due after Rolling Year Five	0
Operating Lease, Liability, Current	17
Operating Lease, Liability, Noncurrent	11
Operating Lease, Liability, Total	$ 28