XML 20 R43.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Note J - Treasury Stock (Details Textual) (USD $) | 9 Months Ended |  |  |
--- | --- | --- | --- | ---
Mar. 31, 2015 | Mar. 31, 2014 | Feb. 06, 2015 | Jun. 02, 2011 | May 11, 2015
Stock Repurchase Program, Authorized Amount |  |  | $ 3,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1 | $ 2,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1 |
Treasury Stock, Shares, Acquired | 157,539 us-gaap_TreasuryStockSharesAcquired | 5,100 us-gaap_TreasuryStockSharesAcquired |  |  |
Treasury Stock Acquired, Average Cost Per Share | $ 5.57 us-gaap_TreasuryStockAcquiredAverageCostPerShare | $ 4.55 us-gaap_TreasuryStockAcquiredAverageCostPerShare |  |  |
Treasury Stock, Value, Acquired, Cost Method | 878,000 us-gaap_TreasuryStockValueAcquiredCostMethod | 23,000 us-gaap_TreasuryStockValueAcquiredCostMethod |  |  |
2015 Increase [Member] | Subsequent Event [Member] |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  |  | 2,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1 / us-gaap_ShareRepurchaseProgramAxis = naii_Increase2015Member / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
2015 Increase [Member] |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  | 1,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1 / us-gaap_ShareRepurchaseProgramAxis = naii_Increase2015Member |  |
Subsequent Event [Member] |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  |  | $ 5,000,000 us-gaap_StockRepurchaseProgramAuthorizedAmount1 / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total cost of shares repurchased divided by the total number of shares repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 + Details
Name: | us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares that have been repurchased during the period and are being held in treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
Name: | us-gaap_TreasuryStockSharesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 + Details
Name: | us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ShareRepurchaseProgramAxis=naii_Increase2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |