Fair Value Measurements (Details 1) (Level 3 Derivative Instruments [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
	Sep. 30, 2014
Level 3 Derivative Instruments [Member]
Reconciliation of fair value activity for Level 3 derivative contracts
Balance as of March 31, 2012	$ (19)	[1]
Realized/unrealized gain included in earnings	7	[1],[2]
Settlements	(3)	[1]
Balance as of September 30, 2012	$ (15)	[1]

[1] Represents net derivative liabilities.

[2] Included in “Other expense (income), net.”