Final Allocation of Purchase Price (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Nov. 14, 2019	Dec. 31, 2018	Apr. 25, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 416,431		$ 381,850		$ 252,011
Autoguide LLC [Member]
Business Acquisition [Line Items]
Goodwill		$ 41,372
Intangible assets		37,660
Other current assets		3,661
Non-current assets		1,227
Accounts payable and current liabilities		(1,223)
Long-term deferred tax liabilities		(949)
Total purchase price		$ 81,748
Mobile Industrial Robots (MiR)
Business Acquisition [Line Items]
Goodwill				$ 135,976
Intangible assets				80,670
Other current assets				6,039
Non-current assets				1,336
Accounts payable and current liabilities				(7,336)
Long-term deferred tax liabilities				(18,007)
Other long-term liabilities				(900)
Total purchase price				$ 197,778