Stock-based Compensation - Summary of Total Stock-based Compensation Cost from Stock Options, RSUs, ESPP, RSAs, and Sales of Stock (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 227,161	$ 43,960	$ 19,238
Stock-based compensation capitalized for software development	5,247	575	1,253
Total stock-based compensation cost	232,408	44,535	20,491
Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	8,094	1,722	1,095
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	68,755	13,385	7,463
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	85,040	12,930	6,584
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 65,272	$ 15,923	$ 4,096