Financial instruments - Additional Information (Details) € in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2021 USD ($)	Jun. 28, 2020 USD ($)	Jun. 27, 2021 USD ($)	Jun. 28, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) Financial_Institution_Counterparty	Dec. 31, 2019 EUR (€) Financial_Institution_Counterparty	Dec. 31, 2018 USD ($) Financial_Institution_Counterparty	Dec. 31, 2018 EUR (€) Financial_Institution_Counterparty
Derivatives Fair Value [Line Items]
Allowance for credit losses	$ 12,100,000		$ 12,100,000		$ 12,900,000
Allowance for credit losses, current	7,100,000		7,100,000		8,100,000
Cash flow hedging
Derivatives Fair Value [Line Items]
Ineffectiveness related to derivatives	0	$ 0	0	$ 0
Foreign exchange contract | Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Gain related to currency forward contracts	700,000			$ 800,000
Loss related to currency forward contracts		$ 800,000	2,500,000
Total notional amount for all open foreign currency forward contracts	189,200,000		$ 189,200,000		163,500,000
Derivative, term of contract			12 months
Foreign exchange contract | Designated as Hedging Instrument | Cash flow hedging
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts	$ 137,000,000.0		$ 137,000,000.0		$ 129,500,000
Cross-currency interest rate swaps | Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Total notional amount for all open foreign currency forward contracts						$ 250,000,000	€ 219.2	$ 500,000,000	€ 433.9
Derivative, number of instruments held | Financial_Institution_Counterparty						5	5	6	6
Derivative, fixed interest rate						4.875%	4.875%	4.625%	4.625%
Derivative, annual interest rate						2.4595%	2.4595%	1.942%	1.942%