Note 10 - Accrued Pension Liabilities - Assumptions Used in the Measurement of the Pension Expense and Benefit Obligation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Discount rate	1.90%	1.80%	1.70%
Expected return on plan assets			4.59%
Rate of compensation increase	2.50%	2.50%	2.50%