Interim Financial Data (Policies)	6 Months Ended
Interim Financial Data (Policies)	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The information furnished in these unaudited interim consolidated financial statements as of and for the three and six months ended September 30, 2017 and 2016 has been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”). In the opinion of management, the unaudited consolidated financial information reflects all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the results for the interim periods presented. The results of operations for the three and six months ended September 30, 2017 do not necessarily indicate the results which may be expected for the full fiscal year ending March 31, 2018 (“fiscal 2018”). These financial statements should be read in conjunction with the Consolidated Financial Statements, significant accounting policies, and other Notes to Consolidated Financial Statements included in Toyota Motor Credit Corporation’s Annual Report on Form 10-K (“Form 10-K”) for the fiscal year ended March 31, 2017 (“fiscal 2017”), which was filed with the Securities and Exchange Commission on June 1, 2017. References herein to “TMCC” denote Toyota Motor Credit Corporation, and references herein to “we”, “our”, and “us” denote Toyota Motor Credit Corporation and its consolidated subsidiaries. Related party transactions are disclosed in Note 14 – Related Party Transactions.
New Accounting Guidance	New Accounting Guidance In May 2014, the Financial Accounting Standards Board ("FASB") issued new guidance on the recognition of revenue from contracts with customers. This comprehensive standard will supersede virtually all existing revenue recognition guidance. In August 2015, the FASB issued a one-year deferral of the effective date, with early adoption as of the original effective date permitted. The FASB also subsequently issued guidance amending and clarifying various aspects of the new revenue recognition standard. We plan to adopt the new revenue guidance effective April 1, 2018 with a cumulative-effect adjustment to the current period opening balance of retained earnings. We do not expect the adoption of this standard to have a material impact on our operating lease, retail and dealer financing revenues as the majority of those revenues are outside the scope of the standard. However, certain products within our insurance operations fall within the scope of this guidance. Based on our evaluation of contracts related to those products, we expect the application of this guidance will result in changes to both the timing of recognition and the classification of revenues and expenses. While our assessment is not complete, we do not expect these changes to have a material impact on our income before taxes. We continue to assess the impact of this guidance on our consolidated financial statements and related disclosures. In January 2016, the FASB issued new guidance that addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments and will require entities to measure equity investments at fair value and recognize any changes in fair value in earnings. We will adopt this new guidance effective April 1, 2018 with a cumulative-effect adjustment to the current period opening balance of retained earnings. This guidance also requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from changes in instrument-specific credit risk for instruments where the entity has elected the fair value option. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements. In February 2016, the FASB issued new guidance that introduces a lessee model that brings most leases on the balance sheet and aligns many of the underlying principles of the new lessor model with those in the new revenue recognition standard. The new leasing standard represents a wholesale change to lease accounting for lessees. Upon adoption, we expect to recognize lease liabilities and right-of-use assets (at their present value) in our Consolidated Balance Sheets related to predominantly all of the future minimum lease payments as disclosed in Note 12 – Commitments and Contingencies. This accounting guidance is effective for us on April 1, 2019. We continue to evaluate the other potential impacts of this guidance on our consolidated financial statements and related disclosures. In June 2016, the FASB issued new guidance that introduces a new impairment model based on expected losses rather than incurred losses for certain types of financial instruments. It also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. We expect this new guidance will result in an increase in our allowance for credit losses; the magnitude of which is under evaluation. This accounting guidance is effective for us on April 1, 2020. We are currently evaluating the other potential impacts of this guidance on our consolidated financial statements. In August 2016, the FASB issued new guidance that is intended to reduce diversity in practice in the classification of certain items in the statement of cash flows. This accounting guidance is effective for us on April 1, 2018. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements and related disclosures. In November 2016, the FASB issued new guidance that clarifies how restricted cash and cash equivalents should be classified and presented in the statement of cash flows and requires new disclosures related to restricted cash and cash equivalents. This guidance was intended to reduce diversity in practice in the classification of restricted cash and cash equivalents on the statement of cash flows. This accounting guidance is effective for us on April 1, 2018 at which time we will no longer report the change in restricted cash and cash equivalents in the operating or investing sections in our Consolidated Statements of Cash Flows, and cash and cash equivalents at the beginning and end of the period will include restricted cash and cash equivalents. These changes will be applied using a retrospective transition method to each period presented. In March 2017, the FASB issued new guidance that requires certain premiums on callable debt securities to be amortized to the earliest call date. This accounting guidance is effective for us on April 1, 2019. We are currently evaluating the potential impact of this guidance on our consolidated financial statements. Note 1 – Interim Financial Data (Continued) In August 2017, the FASB issued new guidance that makes targeted improvements to accounting for hedging activities. This guidance eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires, for qualifying hedges, the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. The guidance provides new alternatives for applying hedge accounting and measuring the hedged item in fair value hedges of interest rate risk. The guidance also modifies the accounting for components excluded from the assessment of hedge effectiveness, eases documentation and assessment requirements and modifies certain disclosure requirements. This accounting guidance is effective for us on April 1, 2019. We are currently evaluating the potential impact of this guidance on our consolidated financial statements and disclosures.
Recently Adopted Accounting Guidance	Recently Adopted Accounting Guidance In April 2017, we adopted new FASB accounting guidance which clarifies that a change in the counterparty to a designated derivative hedging instrument does not, in and of itself, require de-designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The adoption of this guidance did not have an impact on our consolidated financial statements. In April 2017, we adopted new FASB accounting guidance which clarifies whether an embedded contingent put or call option is clearly and closely related to the debt host when bifurcating an embedded derivative. The adoption of this guidance did not have an impact on our consolidated financial statements. In April 2017, we adopted new FASB accounting guidance that further amends the analysis a reporting entity must perform to determine whether it should consolidate certain legal entities. This guidance specifically addresses interests held through related parties that are under common control. The adoption of this guidance did not change our consolidation conclusions and therefore did not have an impact on our consolidated financial statements.