Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013 Thermax and Raydex [Member]	Dec. 31, 2012 Thermax and Raydex [Member]	Sep. 29, 2013 Cooper Industries [Member]	Dec. 31, 2012 Cooper Industries [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense (benefit)	$ 5,700,000	$ (21,887,000)	$ 18,123,000	$ (15,024,000)
Effective tax rate	16.40%		18.30%
Applicable Statutory United States Tax Rate			35.00%
Tax benefit due to the impact of tax law changes			5,200,000
Income tax expense for uncertain tax position liability			3,700,000
Income tax benefit, reduction in deferred tax asset valuation allowance, foreign net operating loss				5,200,000
Significant tax items settlement payment					41,800,000		30,000,000
Pre-tax gain on sale of business						211,600,000
Tax benefit recognized								$ 21,000,000