Pension and retirement plans (Periodic Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 31, 2016	Jan. 02, 2016
Components of net periodic pension costs
Service cost	$ 10,848	$ 9,935	$ 21,696	$ 20,421
Interest cost	3,774	5,328	7,548	10,656
Expected return on plan assets	(10,588)	(10,071)	(21,176)	(20,142)
Recognized net actuarial loss	3,851	3,183	7,702	6,366
Amortization of prior service credits	(393)	(393)	(786)	(786)
Net periodic pension cost	$ 7,492	$ 7,982	$ 14,984	$ 16,515