Note 5 - Prepaid Expenses, Deposits and Other (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Deposits and Other Assets Noncurrent	$ 1,820	$ 1,865
Prepaid Royalties [Member]
Deposits and Other Assets Noncurrent	$ 1,700	$ 1,800	$ 1,600