Note 9 - Pensions - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014
United States Pension Plan of US Entity [Member]
Service cost	$ 250	$ 150	$ 750	$ 450
Interest cost	1,032	971	3,094	2,913
Expected return on plan assets	(917)	(1,412)	(2,749)	(4,234)
Amortization of net loss	290	137	870	411
Total cost (credit) of the plan	655	(154)	1,965	(460)
Net periodic benefit cost (credit)	655	$ (154)	1,965	$ (460)
Settlement charge	30,194		30,194
Total pension cost (credit)	30,849	$ (154)	32,159	$ (460)
Foreign Pension Plan [Member]
Service cost	314	311	944	933
Interest cost	512	591	1,538	1,774
Expected return on plan assets	(599)	(572)	(1,800)	(1,718)
Amortization of net loss	62	47	185	142
Total cost (credit) of the plan	289	377	867	1,131
Net periodic benefit cost (credit)	$ 289	$ 377	$ 867	$ 1,131
Settlement charge
Total pension cost (credit)	$ 289	$ 377	$ 867	$ 1,131
Settlement charge	$ 30,194		$ 30,194