Stock-Based Compensation - Summary of Stock-Based Compensation Expense for Employees and Nonemployees (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 9,160,000	$ 1,925,000	$ 43,390,000	$ 3,329,000
Share-based payment arrangement, amount capitalized	300,000	0	300,000	0
Marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	772,000	367,000	2,618,000	658,000
Selling, general, and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 8,388,000	$ 1,558,000	$ 40,772,000	$ 2,671,000