Pension plan (Details ) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 29, 2012	Dec. 31, 2011
Components of net periodic pension costs
Service cost	$ 9,230	$ 7,095	$ 18,460	$ 14,190
Interest cost	3,663	3,731	7,326	7,462
Expected return on plan assets	(6,976)	(6,734)	(13,952)	(13,468)
Recognized net actuarial loss	3,724	2,420	7,448	4,840
Amortization of prior service credit	(393)	(469)	(786)	(938)
Net periodic pension cost	$ 9,248	$ 6,043	$ 18,496	$ 12,086