Taxes - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Jun. 29, 2014	Sep. 28, 2014	Sep. 29, 2013	Dec. 31, 2013	Jun. 30, 2013 Research and Development Tax Credit
Tax Credit Carryforward [Line Items]
Unrecognized Tax Benefits, Increase/Decrease Resulting from Prior Period Tax Positions	$ 674,000	$ 267,000
Income Tax Reconciliation Reductions Resulting From Lapse Of Applicable Statute Of Limitations	217,000	1,790,000
Income Tax Examination, Increase (Decrease) in Liability from Prior Year			553,000
Increase (decrease) in liability for release of tax reserve			296,000
Effective Income Tax Rate Continuing Operations	19.00%				19.00%
Tax credit carryforward							555,000
Provision for effective tax rate	18.00%	13.00%		18.00%	16.00%
Increase (decrease) in liabilities, net of deferred tax benefit, for uncertain tax positions	(217,000)			47,000
Increase (decrease) in interest and penalties	13,000			74,000
Unrecognized tax benefit shown as a reduction to noncurrent deferred tax assets	1,028,000			1,028,000
Liability For Uncertain Tax Positions	4,970,000			4,970,000
Reserve for income taxes, total	3,942,000			3,942,000		4,765,000
Interest and penalties, gross	468,000			468,000
Reserve for income taxes to be recorded in additional paid in capital				557,000
Minimum decrease in income tax expense due to release in reserves				300,000
Maximum decrease in income tax expense due to release in reserves				$ 400,000
Tax years open to examination by Internal Revenue Service				2012 through 2013
Tax years open to examination by various taxing authorities				2011 through 2013
Tax years open to examination by various taxing authorities for other entities				2010 through 2013