Acquisitions - Additional Information (Detail) - USD ($)			2 Months Ended	3 Months Ended		6 Months Ended
	Apr. 25, 2018	Feb. 26, 2018	Jul. 01, 2018	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
Revenues			$ 4,500,000
Income (loss) before income taxes			(1,500,000)
Goodwill			388,625,000	$ 388,625,000		$ 388,625,000		$ 252,011,000
Mobile Industrial Robots (MiR)
Business Acquisition [Line Items]
Total preliminary purchase price	$ 196,630,000
Cash paid to acquire outstanding common and preferred stock	145,200,000
Contingent consideration	51,400,000
Arrangement range of outcomes value high			$ 117,000,000	117,000,000		117,000,000
Goodwill, not deductible for tax purposes	135,700,000
Net income				101,780,000	$ 172,238,000	186,787,000	$ 251,728,000
Goodwill	$ 135,747,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 years 4 months 24 days
Mobile Industrial Robots (MiR) | Fair Value Adjustment to Inventory
Business Acquisition [Line Items]
Net income				400,000		400,000	400,000
Mobile Industrial Robots (MiR) | Acquisition Related Costs
Business Acquisition [Line Items]
Net income				$ 2,300,000		$ 2,900,000	$ 2,900,000
Energid Technologies Corporation
Business Acquisition [Line Items]
Total preliminary purchase price		$ 27,600,000
Goodwill		14,400,000
Acquired value of intangible assets		$ 12,300,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		7 years 8 months 12 days
Net tangible assets		$ 1,000,000