Stockholders' Equity - Schedule of Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Net of Tax	$ 172	$ (1,989)	$ 83
Foreign Currency Translation Adjustments, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	113	(1,845)	9
Amounts reclassified to earnings	0	(10)	44
Other Comprehensive Income (Loss), Net of Tax	113	(1,855)	53
Tax expense (benefit)	(23)	0	0
Reclassification, tax expense	0	0	24
Unrealized Losses on Cash Flow Hedges, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	6	(13)	(6)
Amounts reclassified to earnings	3	3	0
Other Comprehensive Income (Loss), Net of Tax	9	(10)	(6)
Tax expense (benefit)	0	0	0
Reclassification, tax expense	0	0	0
Changes in Retirement-Related Benefit Plans, Net Actuarial Gain (Loss) and Prior Service Credit (Cost)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	23	(140)	17
Amounts reclassified to earnings	30	11	22
Tax expense (benefit)	13	(66)	16
Reclassification, tax expense	18	6	12
Changes in Retirement-Related Benefit Plans, Foreign Currency Translation Adjustments and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	(3)	4	(4)
Amounts reclassified to earnings	0	1	1
Tax expense (benefit)	0	0	0
Reclassification, tax expense	$ 0	$ 0	$ 1