Fair value of financial instruments - Narrative (Details) $ in Millions, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 26, 2025 USD ($) contract	Dec. 27, 2024 USD ($)	Dec. 26, 2025 USD ($) contract	Dec. 27, 2024 USD ($)	Jun. 27, 2025 USD ($) contract	Dec. 26, 2025 CAD ($) contract	Jun. 27, 2025 CAD ($) contract
Foreign Currency Fair Value Hedge Derivative [Line Items]
Unrealized gain (loss) on derivatives	$ 1.2	$ (5.1)	$ (0.1)	$ (1.0)
Foreign currency forward contracts
Foreign Currency Fair Value Hedge Derivative [Line Items]
Derivative liabilities, notional amount	$ 11.0		11.0		$ 35.0
Gain/(loss) from accumulated other comprehensive income expected to be reclassified			$ 4.3		$ 1.5
Foreign currency forward contracts | Designated as hedging instrument | Thailand, baht
Foreign Currency Fair Value Hedge Derivative [Line Items]
Number of forward contracts outstanding | contract	200		200		165	200	165
Derivative, notional amount	$ 200.0		$ 200.0		$ 165.0
Foreign currency forward contracts | Designated as hedging instrument | Canada, dollars
Foreign Currency Fair Value Hedge Derivative [Line Items]
Number of forward contracts outstanding | contract	1		1		1	1	1
Derivative liabilities, notional amount						$ 0.4	$ 0.5