XML 16 R33.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Note F - Defined Benefit Pension Plan (Details) | Dec. 31, 2013
--- | ---
Compensation and Retirement Disclosure [Abstract] |
Number Of Years Compensation Used For Benefit Obligation Assumptions | 5 years

X
- Definition Number Of Years Compensation Used For Benefit Obligation Assumptions + References No definition available. + Details
Name: | naii_NumberOfYearsCompensationUsedForBenefitObligationAssumptions
Namespace Prefix: | naii_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration