Business Combinations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		1 Months Ended	12 Months Ended	1 Months Ended
	Mar. 31, 2013	Mar. 31, 2014	Aug. 31, 2011 PopCap [Member]	Mar. 31, 2012 Series Of Individually Immaterial Business Acquisitions [Member]	Aug. 31, 2011 Maximum [Member] PopCap [Member]	Aug. 31, 2011 In-Process Research And Development Projects Acquired [Member] PopCap [Member]
Business Acquisition [Line Items]
Date of purchase agreement			Aug. 31, 2011
Aggregate purchase price in cash			$ 645	$ 55
Acquisition-related contingent consideration payment			87
Maximum period in years to grant long-term equity retention awards					4 years
Maximum value of restricted stock unit awards and options to be granted			50
Contingent consideration maximum payment	566	10	550
Contingent consideration, fair value			95
Aggregated fair value of in process research and development projects acquired			15
Average weighted average cost of capital						13.00%
Assigned fair value of acquired IPR&D projects						4
Estimated costs to complete acquired IPR&D projects						2
Aggregate cost to complete acquired IPR&D projects						$ 5
Weighted-average estimated percentage completion of in-process research and development projects						36.00%
Number of businesses acquired	1			4