Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Accrued other long-term liabilities	$ 6.3		$ 6.3
Estimated sales and marketing expense	0.4	$ 0.3	1.1	$ 1.0
Freezing amount in cash resulted from court pending legal action issued		$ 0.5		$ 0.5
Accruals related court pending legal dispute	$ 1.3		$ 1.3