Note 5 - Share Repurchase Program (Details Textual) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Nov. 04, 2015	Dec. 31, 2007
Stock Repurchase Program, Number of Shares Authorized to be Repurchased					2,000,000	1,000,000
Stock Repurchase Program, Authorized Amount					$ 40,000
Stock Repurchased and Retired During Period, Shares	0	455,581	941,024	0
Stock Repurchased and Retired During Period, Value		$ 7,513	$ 16,200