Income Tax Provision - Additional Information (Details) (USD $)	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Operating Loss Carryforwards [Line Items]
Lease Related Charge-Offs Reclassified From Provision for Credit and Residual Value Losses to Lease Transactions		$ 18,000,000
Deferred Tax Assets, Tax Credit Carryforwards, Federal and State	96,000,000	80,000,000
Valuation Allowance	20,000,000	18,000,000
Income taxes paid (received), net	143,000,000	(30,000,000)	21,000,000
Unremitted earnings in foreign subsidiary	196,000,000
Income Taxes Receivable	174,000,000	0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		1,000,000	1,000,000
Amounts Remaining in Unrecognized Tax Benefits		0
Decrease in Unrecognized Tax Benefits	0	1,000,000	0
Interest on Income Taxes Accrued, Maximum	1,000,000	1,000,000	1,000,000
Income Tax Penalties Accrued	0	0	0
TMCC-affiliated companies [Member]
Operating Loss Carryforwards [Line Items]
Income Taxes Receivable	5,000,000	1,000,000
Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	1,435,000,000	591,000,000
State [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	71,000,000	56,000,000
Income Tax Payable		11,000,000
Income Taxes Receivable	13,000,000
Expiration Beginning Date [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Expiration Dates	Mar. 31, 2029
Expiration Beginning Date [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Expiration Dates	Mar. 31, 2016	Mar. 31, 2015
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	1,000,000
Amounts Remaining in Unrecognized Tax Benefits	0
Decrease in Unrecognized Tax Benefits	$ 1,000,000
Maximum [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Expiration Dates	Mar. 31, 2035
Maximum [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Expiration Dates	Mar. 31, 2035	Mar. 31, 2034