Financial Guarantees and Warranties (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2014
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 4
Guarantor obligations, maximum exposure	272
Guarantee obligations, expiring in 2015	154
Guarantee obligations, expiring in 2016	31
Guarantee obligations, expiring in 2017	17
Guarantee obligations, expiring in 2018	21
Guarantee obligations, expiring in 2019	37
Guarantee obligations, expiring after 2019	216
Financial Guarantee [Member] | Minimum [Member]
Guarantor Obligations [Line Items]
Number of years for which agreements or guarantees extend	P1Y
Financial Guarantee [Member] | Maximum [Member]
Guarantor Obligations [Line Items]
Number of years for which agreements or guarantees extend	P2Y
Guarantee Obligations Customers Debt [Member] | Minimum [Member]
Guarantor Obligations [Line Items]
Number of years for which agreements or guarantees extend	P1Y
Guarantee Obligations Customers Debt [Member] | Maximum [Member]
Guarantor Obligations [Line Items]
Number of years for which agreements or guarantees extend	P15Y
Guarantee Obligations Inventory Repurchase Guarantees [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure	204
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure	161
Commitment to investee building and equipment construction [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure	$ 40