Note 8 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leases, Rent Expense, Net	$ 2.5	$ 2.8	$ 3.0
Notional Value of Letters of Credit Performance Bonds and Other Guarantees	$ 1.2	$ 1.8