Severance and Retention - Summary of Severance and Retention Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost And Reserve [Line Items]
Severance and retention expense	$ 1,403	$ 1,423
Cost of Revenues [Member]
Restructuring Cost And Reserve [Line Items]
Severance and retention expense	301	8
General and Administrative [Member]
Restructuring Cost And Reserve [Line Items]
Severance and retention expense	567	799
Sales and Marketing [Member]
Restructuring Cost And Reserve [Line Items]
Severance and retention expense	516	$ 616
Research and Development [Member]
Restructuring Cost And Reserve [Line Items]
Severance and retention expense	$ 19