Note 6 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	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	119,533		119,533
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term			3 years
Share-based Payment Arrangement, Expense	$ 0.1	$ 0.1	$ 0.2	$ 0.2
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 0.5		$ 0.5
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			2 years 146 days
Share-based Payment Arrangement, 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, Ending Balance	20,000		20,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 0.1		$ 0.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	20,000		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, Options, Outstanding, Number, Ending Balance	260,008		260,008
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross				0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 1.5		$ 1.5
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			110,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 5.53
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			47,494
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period			0
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	2.2		$ 2.2
Portion Relating to RSU Grants Not Expected to be Awarded [Member] | The 2012 Stock Incentive Plan [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 1.7		$ 1.7
Minimum [Member] | Share-based Payment Arrangement, 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] | Share-based Payment Arrangement, 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