Note 8 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended		19 Months Ended
	May 29, 2018	Dec. 31, 2019	Dec. 31, 2018	May 29, 2018	Oct. 25, 2016
Treasury Stock, Value, Acquired, Cost Method		$ 9,767	$ 5,248
The 2016 Stock Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount					$ 25,000
Treasury Stock, Shares, Acquired			437,000	1,279,000
Treasury Stock Acquired, Average Cost Per Share			$ 12.01	$ 14.59
Treasury Stock, Value, Acquired, Cost Method			$ 5,200	$ 18,700
The 2018 Stock Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount	$ 25,000			$ 25,000
Stock Repurchase Program, Period in Force	2 years
Treasury Stock, Shares, Acquired		785,000	0
Treasury Stock Acquired, Average Cost Per Share		$ 12.43
Treasury Stock, Value, Acquired, Cost Method		$ 9,800
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 15,200