Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts Payable And Accrued Liabilities Current [Abstract]
Accrued compensation	$ 3,111	$ 5,801
Accrued content fees and other costs of revenue	110	342
Accrued taxes	227	206
Other	1,162	1,500
Total	$ 4,610	$ 7,849