Changes in accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2024	Jul. 01, 2023	Jun. 29, 2024	Jul. 01, 2023
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period			$ (223,198)	$ (278,472)
Other comprehensive income before reclassification			(20,025)	38,918
Amounts reclassified from accumulated other comprehensive income			(13,415)	(14,158)
Net current-period other comprehensive income			(33,440)	24,760
End of Period	$ (256,638)	$ (253,712)	(256,638)	(253,712)
Accumulated Other Comprehensive (income) Loss, Defined Benefit Plan, Tax	4,300	(1,900)	4,300	(1,900)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Tax	10,300	16,100	10,300	16,100
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax			300	100
Unrealized gain on interest rate swap, tax	748	2,172	(856)	(738)
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period			(145,490)	(205,345)
Other comprehensive income before reclassification			(36,014)	31,851
Amounts reclassified from accumulated other comprehensive income			0	0
Net current-period other comprehensive income			(36,014)	31,851
End of Period	(181,504)	(173,494)	(181,504)	(173,494)
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period			(109,713)	(121,701)
Other comprehensive income before reclassification			(565)	6,106
Amounts reclassified from accumulated other comprehensive income			1,010	1,126
Net current-period other comprehensive income			1,575	(4,980)
End of Period	(108,138)	(126,681)	(108,138)	(126,681)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent | Interest Rate Swap
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period			32,005	48,574
Other comprehensive income before reclassification			15,424	13,173
Amounts reclassified from accumulated other comprehensive income			(14,425)	(15,284)
Net current-period other comprehensive income			999	(2,111)
End of Period	$ 33,004	$ 46,463	$ 33,004	$ 46,463