Note F - Defined Benefit Pension Plan (Details)	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Number Of Years Compensation Used For Benefit Obligation Assumptions	5 years

Number Of Years Compensation Used For Benefit Obligation Assumptions

No definition available.

Name:	naii_NumberOfYearsCompensationUsedForBenefitObligationAssumptions
Namespace Prefix:	naii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant