Pension plan (Details Textuals) (USD $)	3 Months Ended	6 Months Ended
Dec. 29, 2012	Dec. 29, 2012
Compensation and Retirement Disclosure [Abstract]
Company's net contribution in pension plans	$ 10,000,000	$ 20,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year, Description	The Company currently expects to make additional contributions to the Plan of $10,000,000 in each of the remaining quarters of the fiscal year.

The increase in the fair value of plan assets from contributions made by the employer.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration