Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Commitment:
Credit facilities commitments with vehicle and industrial equipment dealers	$ 1,295,000,000	$ 1,106,000,000
Minimum lease commitments	62,000,000	74,000,000
Total commitments	1,357,000,000	1,180,000,000
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	100,000,000	100,000,000
Minimum lease commitments	62,000,000	74,000,000
Total commitments and guarantees	1,457,000,000	1,280,000,000
Future minimum lease payments under non-cancelable operating leases
2015	19,000,000
2016	18,000,000
2017	13,000,000
2018	8,000,000
2019	3,000,000
Thereafter	1,000,000
Total	62,000,000	74,000,000
TMS [Member]
Commitment:
Minimum lease commitments	30,000,000	37,000,000
Guarantor Obligations [Line Items]
Rental expense payments to affiliates	25,000,000	22,000,000	23,000,000
15-year lease agreement between TMCC and TMS	15 years
Minimum lease commitments	30,000,000	37,000,000
Future minimum lease payments under non-cancelable operating leases
Total	30,000,000	37,000,000
Affiliate Pollution Control and Solid Waste Disposal Bonds [Member] | TMCC Affiliates [Member]
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	100,000,000
Guaranty Fee	78,000
Affiliate Pollution Control and Solid Waste Disposal Bonds [Member] | 2028 [Member] | TMCC Affiliates [Member]
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	20,000,000
Affiliate Pollution Control and Solid Waste Disposal Bonds [Member] | 2029 [Member] | TMCC Affiliates [Member]
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	50,000,000
Affiliate Pollution Control and Solid Waste Disposal Bonds [Member] | 2030 [Member] | TMCC Affiliates [Member]
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	10,000,000
Affiliate Pollution Control and Solid Waste Disposal Bonds [Member] | 2031 [Member] | TMCC Affiliates [Member]
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	10,000,000
Affiliate Pollution Control and Solid Waste Disposal Bonds [Member] | 2032 [Member] | TMCC Affiliates [Member]
Guarantor Obligations [Line Items]
Guarantees of affiliate pollution control and solid waste disposal bonds	$ 10,000,000