Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Components of net periodic pension costs
Service cost	$ 3,786	$ 3,734
Interest cost	5,638	6,614
Expected return on plan assets	(12,668)	(13,301)
Amortization of prior service cost (credit)	534	(393)
Recognized net actuarial loss	3,637	2,535
Net periodic pension cost (benefit)	927	(811)
Contributions	0
Selling, General and Administrative Expenses
Components of net periodic pension costs
Net periodic pension cost (benefit)	3,786	3,734
Other Income, net
Components of net periodic pension costs
Net periodic pension cost (benefit)	(2,859)	$ (4,545)
Plan
Components of net periodic pension costs
Estimated future employer pension plan contributions	$ 8,000