Finance Receivables - Delinquency (Details) (Consumer Finance Receivables [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2015 Rate	Mar. 31, 2014 Rate
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 days	$ 880	$ 717
Greater than 60 days	357	336
Greater than 30 days past due	1,237	1,053
In repossession	42	38
Past Due	1,279	1,091
31 - 60 days, Percent of contractual amount due	3.40%	3.10%
Greater than 60 days, Percent of contractual amount due	1.40%	1.40%
Greater than 30 days past due, Percent of contractual amount due	4.80%	4.50%
In repossession, Percent of contractual amount due	0.20%	0.10%
Percent of contractual amount due	5.00%	4.60%
North America Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 days	767	579
Greater than 60 days	259	210
Greater than 30 days past due	1,026	789
In repossession	34	33
Past Due	1,060	822
International Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
31-60 days	113	138
Greater than 60 days	98	126
Greater than 30 days past due	211	264
In repossession	8	5
Past Due	$ 219	$ 269