Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract liability revenue recognized	$ 0.2		$ 7.7
Impairment losses on Contract Assets	0.0	$ 0.0	0.0	$ 0.0
Transaction price allocated to uncompleted contracts	$ 71.3		$ 71.3
Expected time of revenue recognition			over the next 18 months
Performance obligation, description of timing			one year or less