Note 2 - Significant Accounting Policies - Earnings Per Share, Basic and Diluted (Details) - shares	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Shares issued – beginning of period (in shares)	27,795,695		27,795,695		27,121,371	25,939,892	25,011,939	24,748,213
Shares held by subsidiaries (Note 7) (in shares)					(704,309)	(704,309)	(704,309)	(704,309)
Shares outstanding – beginning of period (in shares)	27,091,386		27,091,386		26,417,062	25,235,583	24,307,630	24,043,904
Weighted average shares issued during the period (in shares)	425,714	158,184	1,055,514	209,903
Diluted weighted average shares – end of period (in shares)	26,842,776	24,465,814	26,291,097	24,253,807