Note 17 - Benefit obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
United States Pension Plan of US Entity [Member]
Benefit obligation, beginning of year	$ 64,825	$ 70,709
Interest cost	2,430	3,310	$ 3,057
Actuarial (gain)/loss	(5,263)	11,813
Benefits paid	(3,436)	(3,160)
Settlements		(17,847)
Benefit obligation, end of year	58,556	64,825	70,709
Supplemental Employee Retirement Plan [Member]
Benefit obligation, beginning of year	2,389	3,086
Interest cost	24	33	41
Actuarial (gain)/loss	(4)	2
Benefits paid	(609)	(732)
Benefit obligation, end of year	1,800	2,389	3,086
Foreign Pension Plan [Member]
Benefit obligation, beginning of year	26,700	25,627
Service cost	778	674	743
Interest cost	589	884	658
Actuarial (gain)/loss	(2,397)	5,319
Benefits paid	(697)	(763)
Currency translation effect	(2,225)	(5,041)
Benefit obligation, end of year	$ 22,748	$ 26,700	$ 25,627