Shareholders' equity - Change in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2025	Jun. 30, 2024
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 4,278,140	$ 4,440,988
Other comprehensive (loss) income before reclassifications	56,918	(42,946)
Amounts reclassified from accumulated other comprehensive income	1,097	78,146
Net current-period other comprehensive (loss) income	58,015	35,200
Ending balance	4,242,868	4,558,719
Cash Flow Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,839	1,396
Other comprehensive (loss) income before reclassifications	(9,210)	(780)
Amounts reclassified from accumulated other comprehensive income	464	(2,095)
Net current-period other comprehensive (loss) income	(8,746)	(2,875)
Ending balance	(6,907)	(1,479)
Pension and Other Postretirement Benefit Plans
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,838	(88,049)
Other comprehensive (loss) income before reclassifications	(2,090)	8,735
Amounts reclassified from accumulated other comprehensive income	633	80,241
Net current-period other comprehensive (loss) income	(1,457)	88,976
Ending balance	381	927
Foreign Currency Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(320,346)	(227,752)
Other comprehensive (loss) income before reclassifications	68,218	(50,901)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive (loss) income	68,218	(50,901)
Ending balance	(252,128)	(278,653)
Accumulated Other Comprehensive (Loss) Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(316,669)	(314,405)
Ending balance	$ (258,654)	$ (279,205)