Related Party Transactions - Related Party Transactions Included in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2018	Mar. 31, 2018
Cash and cash equivalents
Cash and cash equivalents	$ 5,581	$ 3,540
Finance receivables, net
Accounts receivable	197	191
Deferred retail subvention income	(1,332)	(1,279)
Investments in operating leases, net
Investments in operating leases, net	38,748	38,697
Deferred lease subvention income	(1,833)	(1,682)
Other assets
Notes receivable from affiliates	56	68
Other receivables, net	174	310
Other liabilities
Unearned insurance premiums and contract revenues	2,522	2,271
Other payables, net	59	74
Notes payable	24	18
Commercial paper [Member]
Cash and cash equivalents
Cash and cash equivalents	0	255
TMCC-affiliated companies [Member]
Investments in marketable securities
Commercial paper	0	52
Investments in operating leases, net
Investments in operating leases, net	6	6
Other liabilities
Unearned insurance premiums and contract revenues	$ 344	$ 328

Amount of deferred operating lease subvention revenue from related parties.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Unsecured short-term debt instrument issued by corporations which are highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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Amount receivable from related parties classified as other.

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Amount payable to related parties classified as other.

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The amount of property, by major property class, net of accumulated depreciation, subject to or available for lease as of the balance sheet date.

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Carrying amount of premiums written on insurance contracts that have not been earned as of the balance sheet date.

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