Note L - Contingencies (Details Textual) - Employee Retention Tax Credit ("ERTC") Refund [Member] - Refundable Tax Credits Claim, ERTC [Member] - USD ($) $ in Thousands	1 Months Ended
Apr. 30, 2025	Jun. 30, 2023
Income Taxes Receivable		$ 3,500
Deferred Tax Assets, Valuation Allowance		$ 0
Tax Year 2021 [Member] \| Subsequent Event [Member]
Proceeds from Income Tax Refund, Federal	$ 2,900

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of income taxes previously overpaid to tax authorities (such as U.S. Federal, state and local tax authorities) representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Also called income tax refund receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash received from federal tax jurisdiction for refund of tax on income. Includes, but is not limited to, national tax received for non-U.S. jurisdiction.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-22

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Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=naii_RefundableTaxCreditsClaimERTCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2021Member
Namespace Prefix:
Data Type:	na
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- Details

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