Note 9 - Line of Credit (Details Textual) - USD ($) $ in Thousands	Mar. 08, 2017	Sep. 30, 2017	Dec. 31, 2016
Long-term Line of Credit, Noncurrent		$ 9,451	$ 14,311
Letters of Credit Outstanding, Amount		800	800
Line of Credit Facility, Remaining Borrowing Capacity		24,700
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 35,000
Line of Credit, Loan Covenants, Waiver Granted, Amount of Legal Settlement and Office Closure Expenses Excluded	$ 1,300
Debt Instrument, Interest Rate, Effective Percentage		2.60%
Long-term Line of Credit, Noncurrent		$ 9,500	$ 14,300
Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 5,000