Derivative instruments (Details Textual) (USD $)	6 Months Ended		12 Months Ended
	Dec. 29, 2013 Contract	Jun. 30, 2013 Contract	Jun. 30, 2013 Currency Buy Sell Under Contract One	Jun. 30, 2013 Currency Buy Sell Under Contract Two
Derivative Instruments (Textual) [Abstract]
Mexican peso contract: contract end date			Jun. 28, 2013	Jun. 28, 2013
Mexican Peso Option Contract - Contractual Exchange Rate			12.40	13.40
Premiums to be paid and received under the weekly Mexican peso currency option contracts net	$ 0
Number of Mexican peso currency option contracts outstanding	0	0