Note 8 - Summary of Stock Options (Details Textual) - USD ($)		1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 22, 2016	Sep. 30, 2016	Aug. 31, 2016	Jan. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Aug. 21, 2016
Two Thousand Five Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance		1,892			1,892		1,892
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		1,892			1,892		1,892
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price		$ 116.29			$ 116.29		$ 116.29
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term							357 days
The 2006 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		38,378			38,378		38,378
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price		$ 10.49			$ 10.49		$ 10.49
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term							6 years 47 days
Conversion of Stock Exchange Ratio							0.0080497
Conversion of Stock, Post Revenue Stock Split Basis, Ratio							0.0010062
The 2013 Plan [Member] | Holdings Greater Than 10 Percent of Shares Outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period							5 years
The 2013 Plan [Member] | Quarterly [Member] | Restricted Stock [Member] | Consultant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
The 2013 Plan [Member] | Restricted Stock [Member] | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				39,494
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 6.24
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period		89
The 2013 Plan [Member] | Restricted Stock [Member] | Board Members [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			5,998
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 7.89
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value			$ 47,000
The 2013 Plan [Member] | Restricted Stock [Member] | Consultant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		25,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 7.58
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		25,000			25,000		25,000
The 2013 Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		64,405			64,405		64,405
The 2013 Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance		610,736			610,736		610,736
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		1,275,538			1,275,538		1,275,538
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price		$ 6.35			$ 6.35		$ 6.35
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term							9 years 10 days
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period							10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period							4 years
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum							10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent							110.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Period Increase (Decrease)	737,500
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	2,000,000									1,262,500
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Percentage Increase of Outstanding Common Stock	4.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross					220,915	43,375	378,932	135,250
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value					$ 3.58	$ 4.08	$ 3.54	$ 2.56
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		1,315,808			1,315,808		1,315,808		1,022,195
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price		$ 6.63			$ 6.63		$ 6.63		$ 6.47
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term							8 years 339 days		9 years 135 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross							378,932
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value							$ 5,000	$ 0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options		$ 2,874,000			$ 2,874,000		$ 2,874,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition							3 years 76 days