Accumulated other comprehensive income (loss) (Details) $ in Thousands	6 Months Ended
	Jun. 29, 2019 USD ($)
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	$ 7,440,059
Ending balance	7,821,591
Foreign currency translation adjustments
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	(782,102)
Current period other comprehensive income	59,020
Ending balance	(723,082)
Pensions, net of tax
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	(9,506)
Current period other comprehensive income	67
Ending balance	(9,439)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Rollforward [Roll Forward]
Beginning balance	(791,608)
Current period other comprehensive income	59,087
Ending balance	$ (732,521)