Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2011	Jun. 30, 2012 Retail Finance Receivables [Member]	Jun. 30, 2012 Variable Interest Entities Securitized Assets [Member]	Mar. 31, 2012 Variable Interest Entities Securitized Assets [Member]	Jun. 30, 2012 Variable Interest Entities Securitized Assets [Member] Retail Finance Receivables [Member]	Mar. 31, 2012 Variable Interest Entities Securitized Assets [Member] Retail Finance Receivables [Member]	Jun. 30, 2012 Variable Interest Entities Securitized Assets [Member] Investments In Operating Leases, Net [Member]	Mar. 31, 2012 Variable Interest Entities Securitized Assets [Member] Investments In Operating Leases, Net [Member]	Jun. 30, 2012 Related Liabilities [Member]	Mar. 31, 2012 Related Liabilities [Member]	Jun. 30, 2012 Related Liabilities [Member] Retail Finance Receivables [Member]	Mar. 31, 2012 Related Liabilities [Member] Retail Finance Receivables [Member]	Jun. 30, 2012 Related Liabilities [Member] Investments In Operating Leases, Net [Member]	Mar. 31, 2012 Related Liabilities [Member] Investments In Operating Leases, Net [Member]
Variable Interest Entity [Line Items]
Restricted Cash				$ 663	$ 682	$ 639	$ 682	$ 24	$ 0
Gross Securitized Assets				11,181	10,726	10,286	10,726	895	0
Net Securitized Assets				10,788	10,530	10,126	10,530	662	0
Debt										9,484	9,789	9,008	9,789	476	0
Other Liabilities			2							2	2		2	0	0
Securities retained by TMCC	$ 660	$ 381