Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 846us-gaap_NetIncomeLoss	$ 914us-gaap_NetIncomeLoss	$ 955us-gaap_NetIncomeLoss
Other comprehensive loss:
Foreign currency translation adjustments	(247)	(16)	(47)
Total other comprehensive loss	(247)	(16)	(47)
Comprehensive income	$ 599us-gaap_ComprehensiveIncomeNetOfTax	$ 898us-gaap_ComprehensiveIncomeNetOfTax	$ 908us-gaap_ComprehensiveIncomeNetOfTax

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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