Amount potentially available for additional borrowing on the Line of Credit Facility.

No definition available.

Name:	ntap_LineOfCreditFacilityAdditionalExpansionOptionAvailable
Namespace Prefix:	ntap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of extensions potentially available to the borrower under the line of credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	ntap_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

Term of extension period for line of credit facility.

+ References

No definition available.

+ Details

Name:	ntap_LineOfCreditFacilityPotentialTermExtensionPeriod
Namespace Prefix:	ntap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-Paragraph 1
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_ProceedsFromLinesOfCredit
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Weighted average interest rate of short-term debt outstanding calculated at point in time.

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
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Balance Type:
Period Type:

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Name:	us-gaap_DebtInstrumentAxis=ntap_LetterOfCreditSubFacilityMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
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Balance Type:
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Name:	srt_RangeAxis=srt_MinimumMember
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Period Type:

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Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
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Data Type:	na
Balance Type:
Period Type:

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Financing Arrangements - Additional Information (Detail)	1 Months Ended	6 Months Ended	12 Months Ended
	Jul. 28, 2017 USD ($) Extension	Oct. 26, 2018 USD ($)	Apr. 27, 2018 USD ($)
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, amount	$ 1,000,000,000
Credit facility, date expiry	Dec. 10, 2021
Credit facility, increase in facility	$ 300,000,000
Credit facility, number of extensions \| Extension	2
Credit facility, extensions period	1 year
Credit facility, amounts drawn		$ 0
Revolving Credit Facility \| Letter Of Credit Sub Facility
Debt Instrument [Line Items]
Credit facility, amount	$ 50,000,000
Commercial Paper
Debt Instrument [Line Items]
Notes issued, principal amount		$ 250,000,000	$ 385,000,000
Weighted-average interest rate		2.45%	2.29%
Commercial Paper \| Maximum
Debt Instrument [Line Items]
Notes issued, principal amount	$ 1,000,000,000
Debt instrument maturity period	397 days	31 days	32 days
Commercial Paper \| Minimum
Debt Instrument [Line Items]
Debt instrument maturity period		4 days	19 days
Senior Notes
Debt Instrument [Line Items]
Notes issued, principal amount		$ 1,550,000,000	$ 1,550,000,000
Senior Notes \| Due September 2019
Debt Instrument [Line Items]
Notes issued, principal amount		$ 400,000,000	400,000,000
Notes issued, interest rate		2.00%
Senior Notes \| Due June 2021
Debt Instrument [Line Items]
Notes issued, principal amount		$ 500,000,000	500,000,000
Notes issued, interest rate		3.375%
Senior Notes \| Due September 2024
Debt Instrument [Line Items]
Notes issued, principal amount		$ 400,000,000	400,000,000
Notes issued, interest rate		3.30%
Senior Notes \| Due December 2022
Debt Instrument [Line Items]
Notes issued, principal amount		$ 250,000,000	$ 250,000,000
Notes issued, interest rate		3.25%