CONSOLIDATED BALANCE SHEETS (Parentheticals) - $ / shares	Dec. 31, 2018	Jun. 30, 2018
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	16,000,000	16,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	20,220,534	19,992,204
Common stock, shares outstanding	20,220,534	19,992,204
Class B common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	20,166,034	20,365,504
Common stock, shares outstanding	20,166,034	20,365,504