Note 13 - Stock Repurchase (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Feb. 29, 2016	Dec. 31, 2015	Jul. 31, 2013
Stock Repurchased and Retired During Period, Shares	0	200,000
Stock Repurchase Program, Authorized Amount			$ 50.0		$ 100.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 5.9
Stock Repurchased and Retired During Period, Value		$ 10.4
Repurchase Stock, Average Price Per Share, During Period		$ 51.33