Shareholders' equity - Change in accumulated other comprehensive income, net of tax (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2022	Mar. 28, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 3,754,748	$ 3,336,457
Other comprehensive income (loss) before reclassifications	(23,026)	(24,725)
Amounts reclassified from accumulated other comprehensive income	1,740	2,288
Net current-period other comprehensive income (loss)	(21,286)	(22,437)
Ending Balance	3,795,534	3,375,791
Accumulated Other Comprehensive (Loss) Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(346,959)	(297,298)
Ending Balance	(368,245)	(319,735)
Cash Flow Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	1,081	(482)
Other comprehensive income (loss) before reclassifications	57	(811)
Amounts reclassified from accumulated other comprehensive income	400	838
Net current-period other comprehensive income (loss)	457	27
Ending Balance	1,538	(455)
Pension and Other Postretirement Benefit Plans
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(138,290)	(150,257)
Other comprehensive income (loss) before reclassifications	246	161
Amounts reclassified from accumulated other comprehensive income	1,340	1,450
Net current-period other comprehensive income (loss)	1,586	1,611
Ending Balance	(136,704)	(148,646)
Foreign Currency Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(209,750)	(146,559)
Other comprehensive income (loss) before reclassifications	(23,329)	(24,075)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income (loss)	(23,329)	(24,075)
Ending Balance	$ (233,079)	$ (170,634)