Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Components of net periodic pension costs
Service cost	$ 3,734	$ 3,868
Interest cost	6,614	5,783
Expected return on plan assets	(13,301)	(13,757)
Amortization of prior service credits	(393)	(393)
Recognized net actuarial loss	2,535	3,746
Net periodic pension benefit	(811)	(753)
Selling, General and Administrative Expenses
Components of net periodic pension costs
Net periodic pension benefit	3,734	3,868
Other Income (Expense), net
Components of net periodic pension costs
Net periodic pension benefit	(4,545)	$ (4,621)
Plan
Components of net periodic pension costs
Contributions	8,000
Estimated future employer pension plan contributions	$ 8,000