Financial Instruments and Derivatives - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 04, 2015	Sep. 28, 2014	Oct. 04, 2015	Sep. 28, 2014	Dec. 31, 2014	Jun. 11, 2015	Oct. 31, 2014	Dec. 31, 2013
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized loss		$ 0	$ 200,000	$ 0
Available-for-sale securities, realized gain	$ 400,000	1,000,000	1,400,000	1,700,000
Contingent consideration	14,447,000		14,447,000		$ 895,000
Contingent consideration adjustment			(2,600,000)	(630,000)
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	73,034,000		73,034,000		583,076,000
Fair market value of investments with unrealized losses greater than one year	300,000		300,000		2,300,000
Fair market value of investments with unrealized losses less than one year	72,700,000		72,700,000		580,800,000
Available-for-sale marketable securities, Unrealized (Loss)	(1,921,000)		(1,921,000)		(867,000)
Gains (losses) on foreign currency transactions	100,000	(400,000)	2,300,000	900,000
Realized gain(loss) on foreign currency contracts	(800,000)	$ 200,000	(2,700,000)	$ (1,600,000)
AIT | Maximum
Financial Instruments and Fair Value [Line Items]
Contingent consideration							$ 2,100,000
Universal Robots
Financial Instruments and Fair Value [Line Items]
Contingent consideration						$ 33,800,000
Universal Robots | Maximum
Financial Instruments and Fair Value [Line Items]
Contingent consideration								$ 65,000,000
Avionics Interface Technologies, LLC
Financial Instruments and Fair Value [Line Items]
Contingent consideration							$ 1,800,000
Contingent consideration adjustment	(1,000,000)		(1,000,000)
Foreign Currency Forward Contracts
Financial Instruments and Fair Value [Line Items]
Notional amount of foreign currency forward contracts	$ 91,500,000		91,500,000		73,000,000
Gains (losses) on foreign currency transactions			$ 0		$ (100,000)