Revenues - Components of Deferred Revenue and Customer Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Deferred Revenue and Customer Liabilities [Line Items]
Deferred revenue and customer liabilities	$ 24,521	$ 26,621
Deferred Revenue and Customer Liabilities [Member]
Schedule of Deferred Revenue and Customer Liabilities [Line Items]
Deferred revenue	3,261	3,012
Customer arrangements with termination rights	13,815	15,024
Estimated refund liabilities	$ 7,445	$ 8,585