Related Party Transactions - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2020	Mar. 31, 2020
Related Party Transactions [Abstract]
Subvention support receivable	$ 227	$ 113

For an unclassified balance sheet, amounts of subvention support due from parties associated with the reporting entity.

No definition available.

Name:	tmcc_SubventionSupportReceivableRelatedParties
Namespace Prefix:	tmcc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant