Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 27, 2025	Dec. 28, 2024	Dec. 27, 2025	Dec. 28, 2024
Components of net periodic pension costs
Service cost within selling, general and administrative expenses	$ 2,719	$ 2,870	$ 5,437	$ 5,740
Interest cost	5,741	6,183	11,483	12,366
Expected return on plan assets	(10,553)	(10,439)	(21,106)	(20,877)
Recognized net actuarial loss and other	2,841	1,287	5,682	2,573
Net periodic pension cost (benefit)	748	(99)	1,496	(198)
Other Income, net
Components of net periodic pension costs
Net periodic pension cost (benefit)	(1,971)	$ (2,969)	(3,941)	$ (5,938)
Plan
Components of net periodic pension costs
Contributions			4,000
Estimated future employer pension plan contributions	$ 4,000		$ 4,000