Lease Obligations - Schedule of Lease Cost (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Finance lease cost
Net lease cost	$ 148
SG&A expenses [Member]
Lessee Lease Description [Line Items]
Operating lease cost	52	[1]
Cost of operations [Member]
Lessee Lease Description [Line Items]
Operating lease cost	89	[1]
Finance lease cost
Amortization of leased assets	3
Net interest expense [Member]
Finance lease cost
Interest on lease liabilities	$ 4

[1] Includes short-term leases and immaterial variable lease costs.