Revenues - Summary of Changes in Certain Contract Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Accounts receivable	$ 38,115	$ 43,673
Short-term deferred revenue and customer prepayments	(5,507)	(5,069)
Long-term deferred revenue	(1,054)	(232)
Deferred expenses	1,897	501
Sales allowances	(741)	$ (548)
Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Accounts receivable	(5,558)
Short-term deferred revenue and customer prepayments	(438)
Long-term deferred revenue	(822)
Deferred expenses	1,396
Sales allowances	$ (193)