Organization, Business and Summary of Significant Accounting Policies - Summary of Revenue from Contracts with Customers (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenues	$ 289,545	$ 312,054
eDiscovery Services [Member]
Disaggregation Of Revenue [Line Items]
Revenues	197,300	215,560
Managed Review [Member]
Disaggregation Of Revenue [Line Items]
Revenues	49,985	50,290
Legal Technology Services [Member]
Disaggregation Of Revenue [Line Items]
Revenues	247,285	265,850
Data Recovery [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 42,260	$ 46,204