Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 30, 2018	Jul. 03, 2021
Components of net periodic pension costs
Service cost	$ 15,145	$ 14,631	$ 15,834
Interest cost	22,552	26,354	23,732
Expected return on plan assets	(50,671)	(53,518)	(54,686)
Amortization of prior service cost (credit)	2,137	(1,571)	(1,573)
Recognized net actuarial loss	14,629	9,251	14,404
Net periodic pension cost (benefit)	3,792	(4,853)	(2,289)
Contributions	8,000	8,000
Selling, General and Administrative Expenses
Components of net periodic pension costs
Net periodic pension cost (benefit)	15,145	14,631	15,834
Other Income, net
Components of net periodic pension costs
Net periodic pension cost (benefit)	$ (11,353)	$ (19,484)	$ (18,123)
Forecast
Components of net periodic pension costs
Estimated future employer pension plan contributions				$ 16,000