Note 10 - Equity Compensation - Stock Options (Details) - USD ($)	9 Months Ended	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2017	Jun. 30, 2016
Outstanding (in shares)	3,119,688	2,976,490	2,976,490
Outstanding (in dollars per share)	$ 9.12	$ 8.97	$ 8.97
Outstanding (Year)	7 years 73 days	7 years 146 days	7 years 146 days	6 years 219 days
Outstanding	$ 2,837,701	$ 4,546,991	$ 2,332,224	$ 8,338,974
Granted (in shares)	794,537	1,256,623
Granted (in dollars per share)	$ 5.98	$ 10.67
Forfeitures (in shares)	(493,609)	(161,812)
Forfeitures (in dollars per share)	$ 11.34	$ 16.17
Exercised (in shares)	(42,939)	(440,146)
Exercised (in dollars per share)	$ 6.66	$ 7.39
Outstanding (in shares)	3,377,677	3,631,155	3,119,688	2,976,490
Outstanding (in dollars per share)	$ 8.09	$ 9.43	$ 9.12	$ 8.97
Exercisable (in shares)	1,586,881	1,423,528
Exercisable (in dollars per share)	$ 8.20	$ 8.99
Exercisable (Year)	5 years 255 days	5 years 109 days
Exercisable	$ 988,080	$ 2,912,714
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	7 years 73 days	7 years 146 days	7 years 146 days	6 years 219 days
Outstanding	$ 2,837,701	$ 4,546,991	$ 2,332,224	$ 8,338,974
Forfeitures (in shares)	(493,609)	(161,812)
Forfeitures (in dollars per share)	$ 11.34	$ 16.17
Exercised (in shares)	(42,939)	(440,146)
Exercised (in dollars per share)	$ 6.66	$ 7.39

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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