Pension plan (Details ) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Dec. 31, 2011	Jan. 01, 2011
Components of net periodic pension costs
Service cost	$ 7,095	$ 7,275	$ 14,190	$ 14,550
Interest cost	3,731	3,600	7,462	7,200
Expected return on plan assets	(6,734)	(6,975)	(13,468)	(13,950)
Recognized net actuarial loss	2,420	2,325	4,840	4,650
Amortization of prior service credit	(469)	(475)	(938)	(950)
Net periodic pension cost	6,043	5,750	12,086	11,500
Pension plan (Textuals) [Abstract]
Company's net contribution in pension plans			$ 0