Note 3 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Millions | 6 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | Sep. 05, 2012 |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | | | 500,000 |
The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant | 284,600 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term | 5 years | | |
Allocated Share-based Compensation Expense | $ 0.2 | $ 0.2 | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $ 0.2 | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | 2 years | | |
The 2012 Stock Incentive Plan [Member] | Total Unrecognized Compensation Including Portion Relating to Grants Not Expected to Be Awarded [Member] | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $ 1.6 | | |
The 2012 Stock Incentive Plan [Member] | Portion Relating to RSU Grants Not Expected to be Awarded [Member] | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $ 1.4 | | |
Employee Stock Option [Member] | The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period | 10 years | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | 20,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | 0 | 0 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $ 0.1 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number | 20,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period | 0 | | |
Restricted Stock Units (RSUs) [Member] | The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number | 153,235 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $ 1.3 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | 14,400 | | |
Minimum [Member] | Employee Stock Option [Member] | The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 1 year | | |
Minimum [Member] | Restricted Stock Units (RSUs) [Member] | The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 1 year | | |
Maximum [Member] | Employee Stock Option [Member] | The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 3 years | | |
Maximum [Member] | Restricted Stock Units (RSUs) [Member] | The 2012 Stock Incentive Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 3 years | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 62,000 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 7.22 | | |