Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2013	Jun. 29, 2012	Jun. 28, 2013	Jun. 29, 2012
U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 16	$ 19	$ 32	$ 38
Interest cost	130	128	260	256
Expected return on assets	(156)	(144)	(312)	(288)
Recognized actuarial net loss	71	62	144	124
Total defined benefit net periodic pension cost	61	65	124	130
Multiemployer benefit expense	295	298	547	576
Net periodic pension cost	356	363	671	706
UK Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	524	599	1,055	1,180
Expected return on assets	(408)	(424)	(822)	(836)
Recognized actuarial net loss	10	23	21	46
Total defined benefit net periodic pension cost	126	198	254	390
Multiemployer benefit expense	0	0	0	0
Net periodic pension cost	$ 126	$ 198	$ 254	$ 390