Segment, Geographic, And Significant Customer Information (Schedule Of Total Cash, Cash Equivalents, Restricted Cash And Investments) (Details) (USD $) In Millions, unless otherwise specified	Apr. 27, 2012	Apr. 29, 2011
Segment, Geographic, And Significant Customer Information [Abstract]
United States	$ 2,697.6	$ 3,037.5
International	2,763.8	2,211.8
Total	$ 5,461.4	$ 5,249.3

Entity wide disclosure on geographic areas cash and cash equivalents and short term investments in entities country of domicile.

No definition available.

Name:	ntap_EntityWideDisclosureOnGeographicAreasCashCashEquivalentsAndShortTermInvestmentsInEntitiesCountryOfDomicile
Namespace Prefix:	ntap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant