Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 03, 2020	Sep. 28, 2019
Components of net periodic pension costs
Service cost	$ 3,938	$ 3,786
Interest cost	3,976	5,638
Expected return on plan assets	(12,420)	(12,668)
Amortization of prior service cost	75	534
Recognized net actuarial loss	5,151	3,637
Net periodic pension cost	720	927
Selling, General and Administrative Expenses
Components of net periodic pension costs
Net periodic pension cost	3,938	3,786
Other Income, net
Components of net periodic pension costs
Net periodic pension cost	(3,218)	$ (2,859)
Plan
Components of net periodic pension costs
Contributions	8,000
Estimated future employer pension plan contributions	$ 8,000