Condensed Consolidated Statements Of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Condensed Consolidated Statements Of Operations [Abstract]
Net revenue	$ 1,061	$ 1,053	$ 2,775	$ 2,499
Cost of goods sold	552	586	1,224	1,171
Gross profit	509	467	1,551	1,328
Operating expenses:
Marketing and sales	269	253	631	553
General and administrative	98	75	260	226
Research and development	325	273	928	825
Amortization of intangibles	11	14	37	44
Acquisition-related contingent consideration	(11)	1	8	(25)
Restructuring and other charges		154	17	162
Total operating expenses	692	770	1,881	1,785
Operating loss	(183)	(303)	(330)	(457)
Gain on strategic investments, net				23
Interest and other income (expense), net	(10)		(13)	6
Loss before provision for (benefit from) income taxes	(193)	(303)	(343)	(428)
Provision for (benefit from) income taxes	12	19	(19)	(1)
Net loss	$ (205)	$ (322)	$ (324)	$ (427)
Net loss per share:
Basic and Diluted	$ (0.62)	$ (0.97)	$ (0.98)	$ (1.29)
Number of shares used in computation:
Basic and Diluted	332	332	331	330