Segment Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Statements of Operations Data:
Net income (loss)	$ 5,070	$ (7,088)
Provision for foreign income taxes	681	416
Depreciation and amortization	1,162	1,440
Interest expense, net	5,994	6,100
Curtailment of bargaining unit plan		1,527
Other income, net	(270)	(131)
Adjusted EBITDA	12,745	2,372
Sciens Management LLC
Statements of Operations Data:
Sciens Management fees and expenses	$ 108	$ 108