Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 04, 2015	Sep. 28, 2014	Oct. 04, 2015	Sep. 28, 2014	Dec. 31, 2014	Oct. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business combination, contingent consideration reduced amount			$ (2,600)	$ (630)
Contingent consideration	$ 14,447		14,447		$ 895
Avionics Interface Technologies, LLC
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business combination, contingent consideration reduced amount	(1,000)		(1,000)
Contingent consideration						$ 1,800
ZTEC Instruments, Inc.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business combination, contingent consideration reduced amount		$ (600)	(1,600)	$ (600)
Contingent consideration	$ 0		$ 0