Restructuring (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended	21 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Dec. 27, 2014	Sep. 26, 2015
Restructuring Reserve [Roll Forward]
Beginning Balance			$ 997	$ 0	$ 0	$ 0
Charges	$ 0	$ 1,715	56	1,715	2,300
Cash Payments			(712)	(432)
Ending Balance	341	1,283	341	1,283	997	341
Employee severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance			383	0	0	0
Charges			45	560		1,100
Cash Payments			(428)	(152)
Ending Balance	0	408	0	408	383	0
Facility termination costs [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance			583	0	0	0
Charges			0	846		900
Cash Payments			(249)	0
Ending Balance	334	846	334	846	583	334
Other [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance			31	0	0	0
Charges			11	309		400
Cash Payments			(35)	(280)
Ending Balance	$ 7	$ 29	$ 7	$ 29	$ 31	$ 7