Inventories - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Amounts credited to the allowance for obsolete inventory	$ 0.5	$ 0.3	$ 0.5
Items charged to the allowance for inventory write-offs	$ 0.1	$ 0.1	$ 0.3