Leases - Schedule of Consolidated Balance Sheet Related To Leases (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Assets
Operating lease assets, net	$ 530	$ 615	$ 664
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Finance lease assets, net	$ 10	$ 15
Total lease assets	$ 540	$ 630
Current
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating lease, current liabilities	$ 129	$ 132
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:DebtCurrent	us-gaap:DebtCurrent
Finance lease, current liabilities	$ 3	$ 3
Noncurrent
Operating lease, noncurrent liabilities	$ 472	$ 541
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtNoncurrent	us-gaap:LongTermDebtNoncurrent
Finance lease, noncurrent liabilities	$ 5	$ 10
Total lease liabilities	$ 609	$ 686