Changes in accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2022	Apr. 03, 2021
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period	$ (359,084)	$ (488,428)
Other comprehensive income before reclassification	7,556	(7,195)
Amounts reclassified from accumulated other comprehensive income	3,961	5,023
Net current-period other comprehensive income	11,517	(2,172)
End of Period	(347,567)	(490,600)
Accumulated Other Comprehensive (income) Loss, Defined Benefit Plan, Tax	(38,500)	(90,000)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Tax	6,400	(8,800)
Accumulated Other Comprehensive Income (Loss), Unrealized Gain (Loss) Certain Investments, tax	900
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax	1,000	(900)
Unrealized gain on interest rate swap, tax	10,892	4,327
Other Comprehensive Income (Loss), Unrealized Gain (loss) Certain Investments, Tax	500
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period	(97,654)	(49,961)
Other comprehensive income before reclassification	(27,191)	(10,614)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income	(27,191)	(10,614)
End of Period	(124,845)	(60,575)
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period	(249,696)	(400,919)
Other comprehensive income before reclassification	(6,244)	3,970
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income	6,244	(3,970)
End of Period	(243,452)	(404,889)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent | Interest Rate Swap
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period	(13,064)	(37,548)
Other comprehensive income before reclassification	27,155	7,389
Amounts reclassified from accumulated other comprehensive income	3,961	5,023
Net current-period other comprehensive income	31,116	12,412
End of Period	18,052	(25,136)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent
Accumulated Other Comprehensive Income [Roll Forward]
Beginning of Period	1,330	0
Other comprehensive income before reclassification	1,348	0
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income	1,348	0
End of Period	$ 2,678	$ 0