Note 2 - Summary of Significant Accounting Policies - Concentration Risk (Details) - USD ($)	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Revenue, related parties	$ 23,926,065	$ 23,551,395
Accounts receivable, related parties	1,762,271	2,124,104
Wainwright [Member]
Revenue, related parties	23,900,000	23,600,000
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Wainwright [Member]
Revenue, related parties	$ 23,926,065	$ 23,551,395
Revenue, related parties, concentration risk percentage	100.00%	100.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Wainwright [Member] | Customers Related to the USO Fund [Member]
Revenue, related parties	$ 13,761,317	$ 14,020,971
Revenue, related parties, concentration risk percentage	58.00%	59.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Wainwright [Member] | Customers Related to the USCI Fund [Member]
Revenue, related parties	$ 4,865,171	$ 4,244,613
Revenue, related parties, concentration risk percentage	20.00%	18.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Wainwright [Member] | Customers Related to the UNG Fund [Member]
Revenue, related parties	$ 3,118,432	$ 3,242,502
Revenue, related parties, concentration risk percentage	13.00%	14.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Wainwright [Member] | All Other Customers [Member]
Revenue, related parties	$ 2,181,145	$ 2,043,309
Revenue, related parties, concentration risk percentage	9.00%	9.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Wainwright [Member]
Revenue, related parties, concentration risk percentage	100.00%	100.00%
Accounts receivable, related parties	$ 1,762,271	$ 2,124,105
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Wainwright [Member] | Customers Related to the USO Fund [Member]
Revenue, related parties, concentration risk percentage	60.00%	59.00%
Accounts receivable, related parties	$ 1,060,421	$ 1,245,396
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Wainwright [Member] | Customers Related to the USCI Fund [Member]
Revenue, related parties, concentration risk percentage	18.00%	19.00%
Accounts receivable, related parties	$ 317,032	$ 400,258
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Wainwright [Member] | Customers Related to the UNG Fund [Member]
Revenue, related parties, concentration risk percentage	12.00%	13.00%
Accounts receivable, related parties	$ 217,760	$ 280,431
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Wainwright [Member] | All Other Customers [Member]
Revenue, related parties, concentration risk percentage	10.00%	9.00%
Accounts receivable, related parties	$ 167,058	$ 198,020