Contingent Liabilities - Additional Information (Detail) Vehicle in Millions, $ in Millions	Jun. 29, 2016 Vehicle	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Loss Contingencies [Line Items]
Product liability accrual		$ 103	$ 328	$ 341	$ 58	$ 54	$ 72
Damages from Product Defects
Loss Contingencies [Line Items]
Number of vehicles recalled | Vehicle	1.4
Toyota Recall | Damages from Product Defects
Loss Contingencies [Line Items]
Product liability accrual				25
Product liability insurance receivable		$ 26
Unannounced Recall | Damages from Product Defects
Loss Contingencies [Line Items]
Product liability accrual				$ 26