Note 6 - Stockholders' Equity (Details Textual) - USD ($) $ in Thousands			3 Months Ended		12 Months Ended	29 Months Ended
	May 02, 2018	May 04, 2016	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2018
Stock Repurchase Program, Period in Force	2 years	2 years
Stock Repurchase Program, Authorized Amount		$ 10,000
Treasury Stock, Shares, Acquired			0			199,543
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 8,300
Stock Issued During Period, Shares, Treasury Stock Reissued for Equity-based Compensation Obligations			18,928	1,226	62,646
Stock Issued During Period, Value, Treasury Stock Reissued for Equity-based Compensation Obligations			$ 100	$ 100	$ 600
Treasury Stock, Shares, Ending Balance			117,969		136,897	136,897
Treasury Stock, Value, Ending Balance			$ 896		$ 1,040	$ 1,040
Common Stock Outstanding [Member]
Treasury Stock, Shares, Acquired				101,573