Subsequent Events - Condensed Proforma Statement of Earnings Loss (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Condensed Income Statements, Captions [Line Items]
Revenues	$ 159,563	$ 137,357	$ 460,636	$ 438,620
Net loss	6,819	5,917	(948)	11,501
Loss per common share
Basic	$ 0.20	$ 0.17	$ (0.03)	$ 0.34
Diluted	$ 0.20	$ 0.17	$ (0.03)	$ 0.33
Post EMS Sale [Member]
Condensed Income Statements, Captions [Line Items]
Revenues			307,075
Net loss			$ (1,709)
Loss per common share
Basic			$ (0.05)
Diluted			$ (0.05)