Financial Instruments and Derivatives - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Apr. 05, 2015	Mar. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2014
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized loss	$ 0	$ 0
Available-for-sale securities, realized gain	500,000	300,000
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	319,060,000		583,076,000
Fair market value of investments with unrealized losses greater than one year	300,000		2,300,000
Fair market value of investments with unrealized losses less than one year	318,800,000		580,800,000
Gains (losses) on foreign currency transactions	4,300,000	600,000
Realized (losses) gains on foreign currency contracts	(3,400,000)	(700,000)
Offsetting foreign exchange contracts	0		0
ZTEC Instruments, Inc. | Maximum
Financial Instruments and Fair Value [Line Items]
Contingent consideration				5,000,000
AIT | Maximum
Financial Instruments and Fair Value [Line Items]
Contingent consideration					2,100,000
Foreign Currency Forward Contracts
Financial Instruments and Fair Value [Line Items]
Notional amount of foreign currency forward contracts	96,200,000		73,000,000
Gains (losses) on foreign currency transactions	$ 0		$ (100,000)