Note 7 - Common Stock (Details Textual) - USD ($)			1 Months Ended					3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 20, 2016	Jun. 17, 2016	Aug. 30, 2016	Jul. 31, 2016	May 31, 2016	Apr. 30, 2016	May 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Jun. 30, 2016	Sep. 30, 2014
June 2016 Issuance Related to 2016 Loan Agreement [Member]
Amortization of Debt Discount (Premium)								$ 35,000		$ 35,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	100,402							100,402		100,402
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 4.98							$ 4.98		$ 4.98
Warrant Term	10 years
Fair Value Assumptions, Expected Dividend Rate	0.00%
Fair Value Assumptions, Expected Volatility Rate	63.00%
Fair Value Assumptions, Risk Free Interest Rate	1.67%
Warrants and Rights Outstanding	$ 350,000
Unamortized Debt Issuance Expense								$ 405,000		$ 405,000
September 2014 Issuance Related to 2014 Loan Agreement [Member]
Amortization of Debt Discount (Premium)								$ 0	$ 47,000	$ 387,000	$ 141,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights														58,962
Class of Warrant or Right, Exercise Price of Warrants or Rights														$ 4.24
Stock Issued During Period, Shares, Exercise of Warrants			17,295
Warrant Term							10 years
May 2015 Issuance Related to 2014 Loan Agreement [Member]
Amortization of Debt Discount (Premium)									2,000		10,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights							3,125
Class of Warrant or Right, Exercise Price of Warrants or Rights							$ 2.96
Stock Issued During Period, Shares, Exercise of Warrants				885
Distributor Warrants, March 2016 Issuance [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights						25,000		25,000		25,000
Class of Warrant or Right, Exercise Price of Warrants or Rights						$ 6.08		$ 6.08		$ 6.08
Warrant Term						10 years
Fair Value Assumptions, Expected Dividend Rate						0.00%
Fair Value Assumptions, Expected Volatility Rate						72.10%
Fair Value Assumptions, Risk Free Interest Rate						1.78%
Allocated Share-based Compensation Expense								$ 0	16,000	$ 162,000	396,000
Contractor Warrants, May 2016 Issuance [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					5,000			5,000		5,000
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 7.74			$ 7.74		$ 7.74
Warrant Term					5 years
Fair Value Assumptions, Expected Dividend Rate					0.00%
Fair Value Assumptions, Expected Volatility Rate					61.60%
Fair Value Assumptions, Risk Free Interest Rate					1.20%
Vendors and Contractors Warrants, October and November 2014 Issuance [Member]
Class of Warrant or Right Number of Securities Called by Warrants or Rights Cancelled In Period										1,094		5,157
June 2016 Offering [Member]
Stock Issued During Period, Shares, New Issues		3,105,000
Share Price		$ 5
Proceeds from Issuance of Common Stock		$ 15,525,000
Proceeds From Issuance of Common Stock, Net		$ 13,886,000
The 2016 Loan Agreement [Member]
Debt Issuance Costs, Net													$ 90,000
Proceeds from Issuance of Common Stock										$ 13,886,000	11,040,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights								425,274		425,274
Class of Warrants or Rights, Exercises in Period										25,268		735
Allocated Share-based Compensation Expense								$ 272,000	$ 55,000	$ 662,000	$ 145,000