Segment Reporting - Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue by geographic area
Total revenue	$ 23,462	$ 30,033	$ 48,847	$ 50,573	$ 33,862	$ 29,218	$ 23,315	$ 28,222	$ 152,915	$ 114,617	$ 1,193,323
United States | Reportable Geographical Components
Revenue by geographic area
Total revenue									64,966	27,093	1,090,794
Non-US | Reportable Geographical Components
Revenue by geographic area
Total revenue									$ 87,949	$ 87,524	$ 102,529