Commitments and contingencies Litigation settlement (Details Textuals 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Dec. 27, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Litigation Settlement [Abstract]
Gain on legal settlement	$ 0	$ 3,000	$ 0	$ 19,137	$ 0	$ 19,137

Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration