Acquisitions 1 (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Mar. 31, 2016	Mar. 31, 2016	Jul. 08, 2015	Mar. 31, 2015	Mar. 31, 2014
Acquisition purchase price allocation
Goodwill		$ 6,086	$ 6,086		$ 5,806	$ 5,922
Estimated useful life
Goodwill, Estimated useful life			Indefinite
Purchased Software | Minimum
Estimated useful life
Finite-lived intangible assets, Estimated useful life (in years)			2 years
Purchased Software | Maximum
Estimated useful life
Finite-lived intangible assets, Estimated useful life (in years)			10 years
Rally
Business Acquisition
Cash acquired from Rally		13
Short-term investments acquired from Rally		48
Acquisition purchase price allocation
Finite-lived intangible assets	[1]	78	$ 78
Goodwill		257	257
Deferred tax liabilities, net		(45)	(45)
Other assets net of other liabilities assumed	[2]	51	51
Purchase price		519	519	$ 519
Rally | Purchased Software
Acquisition purchase price allocation
Finite-lived intangible assets		178	178
Other Fiscal Year 2016 Acquisitions
Acquisition purchase price allocation
Finite-lived intangible assets	[1]	14	14
Goodwill		59	59
Deferred tax liabilities, net		(24)	(24)
Other assets net of other liabilities assumed		2	2
Purchase price		147	147
Other Fiscal Year 2016 Acquisitions | Purchased Software
Acquisition purchase price allocation
Finite-lived intangible assets		$ 96	$ 96
Fiscal Year 2016 Acquisitions | Minimum
Estimated useful life
Finite-lived intangible assets, Estimated useful life (in years)	[1]		1 year
Fiscal Year 2016 Acquisitions | Maximum
Estimated useful life
Finite-lived intangible assets, Estimated useful life (in years)	[1]		15 years
Fiscal Year 2016 Acquisitions | Purchased Software | Minimum
Estimated useful life
Finite-lived intangible assets, Estimated useful life (in years)			5 years
Fiscal Year 2016 Acquisitions | Purchased Software | Maximum
Estimated useful life
Finite-lived intangible assets, Estimated useful life (in years)			7 years

[1] Includes customer relationships and trade names.

[2] Includes approximately $13 million of cash acquired and approximately $48 million of short-term investments acquired relating to Rally.