Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2022	Jan. 01, 2022	Dec. 31, 2022	Jan. 01, 2022
Components of net periodic pension costs
Service cost	$ 3,004	$ 3,751	$ 6,008	$ 7,503
Interest cost	6,683	3,947	13,365	7,894
Expected return on plan assets	(12,215)	(12,284)	(24,430)	(24,568)
Amortization of prior service cost	1	1	2	2
Recognized net actuarial loss	618	4,086	1,235	8,172
Net periodic pension benefit	(1,909)	(499)	(3,820)	(997)
Selling, General and Administrative Expenses
Components of net periodic pension costs
Net periodic pension benefit	3,004	3,751	6,008	7,503
Other Income, net
Components of net periodic pension costs
Net periodic pension benefit	(4,913)	$ (4,250)	(9,828)	$ (8,500)
Plan
Components of net periodic pension costs
Contributions			4,000
Estimated future employer pension plan contributions	$ 4,000		$ 4,000