Note 7 - Employee Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Foreign Plan [Member]
Service cost	$ 187	$ 384
Interest cost	1,353	1,334
Expected return on assets	(1,602)	(1,586)
Amortization of prior service costs	7	0
Recognized net actuarial (gains)/losses	288	309
Net periodic benefit cost	233	441
UNITED STATES | Salary Continuation Plan [Member]
Service cost	0	0
Interest cost	270	313
Amortization of prior service costs	0	0
Net periodic benefit cost	386	404
Amortization of (gain)/loss	$ 116	$ 91