Other Assets and Other Liabilities - Other Assets and Other Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2015	Mar. 31, 2015
Other assets:
Notes receivable from affiliates	$ 1,007	$ 1,184
Used vehicles held for sale	225	188
Deferred charges	121	122
Income taxes receivable	5	174
Derivative assets	51	53
Finance receivables, held-for-sale	2,127	0
Other assets	698	561
Total other assets	4,234	2,282
Other liabilities:
Unearned insurance premiums and contract revenues	1,921	1,825
Derivative liabilities	55	90
Accounts payable and accrued expenses	899	855
Deferred income	441	405
Liabilities held-for-sale	13	0
Other liabilities	174	180
Total other liabilities	$ 3,503	$ 3,355