Note 11 - Retirement Plans - Components of Net Periodic Benefit Cost (Income) for the Domestic and International Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
United States Pension Plan of US Entity [Member]
Components of net periodic benefit cost
Interest cost	$ 597	$ 608	$ 1,792	$ 1,823
Expected return on plan assets	(662)	(718)	(1,986)	(2,153)
Recognized actuarial loss	194	202	582	608
Net periodic benefit cost	129	92	388	278
Foreign Pension Plan [Member]
Components of net periodic benefit cost
Interest cost	186	146	560	442
Recognized actuarial loss	49	83	147	249
Net periodic benefit cost	420	420	1,265	1,271
Service cost	186	193	561	585
Amortization of prior service benefit	$ (1)	$ (2)	$ (3)	$ (5)