Pro Forma Results Under Acquisition (Detail) - Mobile Industrial Robots (MiR) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares
Business Acquisition [Line Items]
Revenue | $	$ 2,303,737
Net income | $	$ 464,602
Net income per common share, basic | $ / shares	$ 2.73
Net income per common share, diluted | $ / shares	$ 2.59