Accrued Liabilities - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued traffic acquisition costs	$ 11,337	$ 22,667
Other accrued liabilities	1,883	2,010
Total accrued liabilities	$ 13,220	$ 24,677

Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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