Acquisitions (Details) (USD $) In Millions, unless otherwise specified			5 Months Ended	9 Months Ended		9 Months Ended							6 Months Ended		6 Months Ended
	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2011 ITKO [Member]	Dec. 31, 2011 ITKO [Member]	Aug. 31, 2011 ITKO [Member]	Dec. 31, 2011 ITKO [Member] Purchased software products [Member] Year	Dec. 31, 2011 ITKO [Member] Minimum [Member] Year	Dec. 31, 2011 ITKO [Member] Maximum [Member] Year	Dec. 31, 2011 Other Fiscal 2012 Acquisitions [Member]	Dec. 31, 2011 Other Fiscal 2012 Acquisitions [Member] Purchased software products [Member] Year	Dec. 31, 2011 Other Fiscal 2012 Acquisitions [Member] Minimum [Member] Year	Dec. 31, 2011 Other Fiscal 2012 Acquisitions [Member] Maximum [Member] Year	Sep. 30, 2011 Arcot [Member]	Dec. 31, 2010 Arcot [Member]	Sep. 30, 2011 Arcot [Member] Purchased software products [Member] Year	Sep. 30, 2011 Arcot [Member] Minimum [Member] Year	Sep. 30, 2011 Arcot [Member] Maximum [Member] Year
Allocation of purchase price and estimated useful lives
Business acquisition, percentage of voting interests acquired					100.00%									100.00%
Finite-lived intangible assets			$ 16	$ 16					$ 11				$ 39
Purchase software			190	190					8				86
Goodwill			160	160					20				62
Deferred tax assets/(liabilities)			(70)	(70)					(3)				(3)
Other assets net of other liabilities assumed			20	20					3				13
Purchase Price			316	316					39				197
Cash acquired from acquisition			20
Estimated Useful Life
Finite-lived intangible assets, estimated useful life						7	3	15		7	3	15			10	2	5
Goodwill, estimated useful life				Indefinite					Indefinite				Indefinite
Acquisitions (Textual)
Accrued acquisition-related costs relative to amounts withheld subject to indemnification protections	$ 39	$ 77