Condensed Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net revenue:
Net revenue	$ 1,286	$ 959	$ 2,423	$ 2,408
Cost of revenue:
Total cost of revenue	418	389	633	543
Gross profit	868	570	1,790	1,865
Operating expenses:
Research and development	339	331	701	656
Marketing and sales	146	160	286	281
General and administrative	117	118	231	223
Acquisition-related contingent consideration	2	0	2	0
Amortization of intangibles	6	2	12	3
Total operating expenses	610	611	1,232	1,163
Operating income (loss)	258	(41)	558	702
Interest and other income (expense), net	18	3	37	9
Income (loss) before provision for (benefit from) income taxes	276	(38)	595	711
Provision for (benefit from) income taxes	21	(16)	47	89
Net income (loss)	$ 255	$ (22)	$ 548	$ 622
Earnings (loss) per share:
Earnings Per Share, Basic	$ 0.84	$ (0.07)	$ 1.80	$ 2.01
Earnings Per Share, Diluted	$ 0.83	$ (0.07)	$ 1.77	$ 1.99
Number of shares used in computation:
Basic	305	309	305	309
Diluted	307	309	309	313
Product [Member]
Net revenue:
Net revenue	$ 623	$ 454	$ 825	$ 1,282
Cost of revenue:
Total cost of revenue	222	300	290	364
Service [Member]
Net revenue:
Net revenue	663	505	1,598	1,126
Cost of revenue:
Total cost of revenue	$ 196	$ 89	$ 343	$ 179