Consolidated Balance Sheet (Supplemental) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Sep. 30, 2013	Mar. 31, 2013
Statement of Financial Position [Abstract]
Variable Interest Entities Assets Liabilities	The following table presents the assets and liabilities of our consolidated variable interest entities. The assets of any variable interest entity can only be used to settle obligations of that respective variable interest entity, and the creditors (or beneficial interest holders) do not have recourse to us or to our other assets. These assets and liabilities are included in the consolidated balance sheet above.
ASSETS
Finance receivables, net	$ 64,212	$ 62,567
Investments in operating leases, net	22,424	20,384
Other Assets	2,134	1,740
Total assets	98,083	95,302
LIABILITIES
Debt	81,529	78,832
Other liabilities	2,879	2,677
Total liabilities	90,869	87,745
Variable Interest Entity, Primary Beneficiary [Member]
ASSETS
Finance receivables, net	8,209	7,556
Investments in operating leases, net	272	434
Other Assets	11	12
Total assets	8,492	8,002
LIABILITIES
Debt	7,118	7,009
Other liabilities	2	1
Total liabilities	$ 7,120	$ 7,010