Fair Value Measurements (Fair Value Measurements Using Significant Unobservable Inputs (Level 3)) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended				12 Months Ended		6 Months Ended	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) Contingent Consideration		Mar. 31, 2012 Significant Unobservable Inputs (Level 3) Contingent Consideration		Sep. 30, 2012 Contingent Consideration Total Payment In Excess of Initial Valuation	Mar. 31, 2012 Playfish Entity [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance			$ 112		$ 51
Additions					100
Change in fair value			(20)	[1]	11	[1]
Payments	26	0	(4)	[2]	(25)	[2]	(4)	(25)
Reclassifications					(25)	[3]		(25)
Ending Balance			$ 88		$ 112

[1] The change in fair value is reported as acquisition-related contingent consideration in our Condensed Consolidated Statements of Operations.

[2] During the six months ended September 30, 2012, we made a payment of $4 million to settle certain performance milestones achieved in connection with one of our acquisitions. During the fourth quarter of fiscal year 2012, we made a payment of $25 million to settle certain performance milestones achieved through December 31, 2011 in connection with our acquisition of Playfish Limited (“Playfish”).

[3] During the fourth quarter of fiscal year 2012, we reclassified $25 million of contingent consideration in connection with our acquisition of Playfish to other current liabilities in our Condensed Consolidated Balance Sheet as the contingency was settled. This amount was paid during the second quarter of fiscal 2013.