Accumulated other comprehensive income (loss) (Details) $ in Thousands	6 Months Ended
	Jun. 27, 2020 USD ($)
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	$ 8,126,448
Current period other comprehensive income (loss)	(200,952)
Ending balance	7,924,864
Foreign currency translation adjustments
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	(753,108)
Current period other comprehensive income (loss)	(201,046)
Ending balance	(954,154)
Pensions, net of tax
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	(12,716)
Current period other comprehensive income (loss)	94
Ending balance	(12,622)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	(765,824)
Ending balance	$ (966,776)