Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018	Dec. 31, 2018
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized gain	$ 500,000	$ 200,000	$ 700,000	$ 600,000
Available-for-sale securities, realized loss			200,000	1,600,000
Available-for-sale marketable securities, Fair Market Value of Investments in debt securities with Unrealized Losses	60,747,000		60,747,000		$ 191,978,000
Fair market value of investments with unrealized losses greater than one year	4,900,000		4,900,000		28,500,000
Aggregate loss of investments with unrealized losses greater than one year	100,000		100,000		1,600,000
Fair market value of investments with unrealized losses less than one year	55,800,000		55,800,000		163,500,000
Aggregate loss of investments with unrealized losses less than one year	100,000		100,000		1,400,000
Unrealized Gain (loss) on contracts	1,500,000	3,700,000	3,400,000	1,200,000
Equity securities unrealized gain loss		$ 1,000,000.0		$ 1,400,000
Equity securities unrealized gain	100,000		3,800,000
Equity securities unrealized loss	200,000		200,000
Debt Mutual Funds
Financial Instruments and Fair Value [Line Items]
Available for sale securities with out contractual maturity date	4,000,000.0		4,000,000.0
Mobile Industrial Robots (MiR)
Financial Instruments and Fair Value [Line Items]
Maximum amount of contingent consideration paid for acquisition	$ 81,000,000.0		81,000,000.0
Foreign Exchange Contracts
Financial Instruments and Fair Value [Line Items]
Unrealized Gain (loss) on contracts			$ 114,900,000		$ 163,100,000