Note I - Treasury Stock	9 Months Ended
Mar. 31, 2018
Notes to Financial Statements
Treasury Stock [Text Block]	I. Treasury Stock On June 2, 2011, the Board of Directors authorized the repurchase of up to $2.0 million of our common stock. On February 6, 2015, the Board of Directors authorized a $1.0 million increase to our stock repurchase plan bringing the total authorized repurchase amount to $3.0 million. On May 11, 2015, the Board of Directors authorized a $2.0 million increase to our stock repurchase plan bringing the total authorized repurchase amount to $5.0 million. On March 28, 2017, the Board of Directors authorized a $2.0 million increase to our stock repurchase plan bringing the total authorized repurchase amount to $7.0 million. Under the repurchase plan, we may, from time to time, purchase shares of our common stock, depending upon market conditions. Purchase of the shares of our common stock may be in open market or privately negotiated transactions. During the three and nine months ended March 31, 2018, we did not repurchase any shares under this repurchase plan. During the nine months ended March 31, 2017, we repurchased 39,547 shares under this plan at a weighted average cost of $8.74 per share and a total cost of $345,000 including commissions and fees. During the three months ended March 31, 2018, we acquired 35,203 shares in connection with restricted stock shares that vested during that period at a weighted average cost of $11.90 per share and a total cost of $419,000. During the nine months ended March 31, 2018, we acquired 43,201 shares in connection with restricted stock shares that vested during that period at a weighted average cost of $11.69 per share and a total cost of $505,000. During the three months ended March 31, 2017, we acquired 32,325 shares from employees in connection with restricted stock shares that vested during the period at a weighted average cost of $8.75 per share and a total cost of $283,000. During the nine months ended March 31, 2017, we acquired 38,729 shares from employees in connection with restricted stock shares that vested during the period at a weighted average cost of $9.47 per share and a total cost of $367,000. These shares were returned to NAI by the related employees and in return NAI paid each employee’s required tax withholding required as a result of the income recognized upon vesting of the restricted shares. The valuation of the shares acquired and thereby the number of shares returned to NAI was calculated based on the closing share price on the date the restricted shares vested.

I. Treasury Stock

June

2011,

the Board of Directors authorized the repurchase of up to

$2.0

million of our common stock. On

February 6, 2015,

the Board of Directors authorized a

$1.0

million increase to our stock repurchase plan bringing the total authorized repurchase amount to

$3.0

million. On

May 11, 2015,

the Board of Directors authorized a

$2.0

million increase to our stock repurchase plan bringing the total authorized repurchase amount to

$5.0

million. On

March 28, 2017,

the Board of Directors authorized a

$2.0

million increase to our stock repurchase plan bringing the total authorized repurchase amount to

$7.0

million. Under the repurchase plan, we

may,

from time to time, purchase shares of our common stock, depending upon market conditions. Purchase of the shares of our common stock

may

be in open market or privately negotiated transactions.

During the

three

and

nine

months ended

March 31, 2018,

we did

not

repurchase any shares under this repurchase plan. During the

nine

months ended

March 31, 2017,

we repurchased

39,547

shares under this plan at a weighted average cost of

$8.74

per share and a total cost of

$345,000

including commissions and fees.

During the

three

months ended

March 31, 2018,

we acquired

35,203

shares in connection with restricted stock shares that vested during that period at a weighted average cost of

$11.90

per share and a total cost of

$419,000.

During the

nine

months ended

March 31, 2018,

we acquired

43,201

shares in connection with restricted stock shares that vested during that period at a weighted average cost of

$11.69

per share and a total cost of

$505,000.

During the

three

months ended

March 31, 2017,

we acquired

32,325

shares from employees in connection with restricted stock shares that vested during the period at a weighted average cost of

$8.75

per share and a total cost of

$283,000.

During the

nine

months ended

March 31, 2017,

we acquired

38,729

shares from employees in connection with restricted stock shares that vested during the period at a weighted average cost of

$9.47

per share and a total cost of

$367,000.

These shares were returned to NAI by the related employees and in return NAI paid each employee’s required tax withholding required as a result of the income recognized upon vesting of the restricted shares. The valuation of the shares acquired and thereby the number of shares returned to NAI was calculated based on the closing share price on the date the restricted shares vested.