Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014 Segment	Jun. 30, 2013
Segment Reporting [Abstract]
Number of reportable segments			2
Segment Reporting Information [Line Items]
Net sales	$ 285,013	$ 145,009	$ 522,894	$ 272,021
Operating (loss) income	7,675	4,003	4,725	2,390
Interest income (expense)-net	92	32	145	64
Other income (expense)-net	(11)	(34)	(64)	(48)
Net loss before provision for income taxes	7,756	4,001	4,806	2,406
North America [Member]
Segment Reporting Information [Line Items]
Operating (loss) income	7,562	3,990	4,614	2,344
United Kingdom [Member]
Segment Reporting Information [Line Items]
Net sales	6,645	3,926	11,323	8,323
Operating (loss) income	113	13	111	46
Segment Reconciling Items [Member] | North America [Member]
Segment Reporting Information [Line Items]
Net sales	280,276	141,842	514,636	266,166
Operating (loss) income	9,470	4,749	7,679	4,812
Segment Reconciling Items [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Net sales	4,737	3,167	8,258	5,855
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(1,908)	(759)	(3,065)	(2,468)
Intersegment Eliminations [Member] | North America [Member]
Segment Reporting Information [Line Items]
Operating (loss) income	(1,908)	(759)	(3,065)	(2,468)
Intersegment Eliminations [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Net sales	1,908	759	3,065	2,468
Reportable Segments [Member]
Segment Reporting Information [Line Items]
Net sales	286,921	145,768	525,959	274,489
Operating (loss) income	$ 7,675	$ 4,003	$ 4,725	$ 2,390