Allowance for Credit Losses - Additional Information (Details) - Finance Receivables, Net [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: Collectively evaluated for impairment	$ 70,140	$ 69,526
Retail and Commercial Loan [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impaired finance receivables aggregated and collectively evaluated for impairment	225	222
Dealer Products [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: Collectively evaluated for impairment	16,148	16,634
TMNA [Member] | Financial Guarantee [Member] | Dealer Products [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: Collectively evaluated for impairment	1,063	1,089
Private Toyota Distributors [Member] | Financial Guarantee [Member] | Dealer Products [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Ending balance: Collectively evaluated for impairment	$ 135	$ 165