XML 24 R43.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Contingencies - Additional Information (Detail) | Dec. 22, 2011 Patent
--- | ---
Legal Proceedings [Line Items] |
Number of patents in lawsuit | 3

X
- Details
Name: | naii_LegalProceedingsLineItems
Namespace Prefix: | naii_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Patents In Lawsuit + References No definition available. + Details
Name: | naii_NumberOfPatentsInLawsuit
Namespace Prefix: | naii_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant