Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012	Dec. 31, 2012	Mar. 31, 2013 Trapeze [Member]	Dec. 31, 2010 Trapeze [Member]	Apr. 01, 2012 Thermax and Raydex [Member]	Mar. 31, 2013 Standby letters of credit [Member]	Mar. 31, 2013 Bank guaranties [Member]	Mar. 31, 2013 Surety bonds [Member]
Loss Contingencies [Line Items]
Reporting Period	90 days	92 days	91 days
Fair value measurements, transfers between Level 1 and Level 2	$ 0
Original maturity period of cash and cash equivalents	Three months or less
Fair value of cash and cash equivalents based on quoted market prices in active markets Level 1 valuation	195,400,000
Contingency accrual at carrying value							7,000,000	4,500,000	1,700,000
Operating results from discontinued operations						24,700,000
Income before taxes from discontinued operations						6,800,000
Proceeds from the sales of Trapeze					152,100,000
Amount received in cash at the end of transaction					136,900,000
Amount in escrow as partial security for Company's indemnity obligations under transaction's purchase and sale agreement					15,200,000
Receivables, net	301,400,000		300,864,000	4,200,000
Amount collected from escrow				$ 3,800,000