Employee Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 04, 2020	Sep. 29, 2019	Oct. 04, 2020	Sep. 29, 2019
nora Defined Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 274	$ 213	$ 791	$ 646
Interest cost	117	170	338	515
Amortization of net actuarial losses	58	0	168	0
Net periodic benefit cost	449	383	1,297	1,161
Foreign Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer Plan, Contributions by Employer	600		1,900
Service cost	0	181	0	550
Interest cost	907	1,223	2,668	3,770
Expected return on assets	(1,082)	(1,378)	(3,184)	(4,251)
Amortization of prior service cost	27	16	79	48
Amortization of net actuarial losses	335	240	981	742
Net periodic benefit cost	187	282	544	859
United States | Salary Continuation Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	234	288	703	865
Amortization of net actuarial losses	140	94	419	281
Net periodic benefit cost	$ 374	$ 382	$ 1,122	$ 1,146