Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Schedule of Fair Value of Employee Stock Options Estimated Using Weighted Average Assumptions

The fair value of employee and director stock options was estimated at the date of grant using the Black-Scholes option pricing model with the weighted average assumptions below.

	Year Ended December 31,
	2019
Expected term (in years)	6.1
Expected volatility	45.0	%
Risk-free interest rate	2.39	%
Dividend yield	—	%

The fair value of market based RSUs was estimated at the date of grant using the Monte-Carlo option pricing model with the assumptions below. Additional details on the Company's market based RSUs are included below.

	Year Ended December 31,
	2020
Expected term (in years)	0.74
Expected volatility	63.0	%
Risk-free interest rate	0.17	%
Dividend yield	—	%

Schedule of Stock-Based Compensation Expense Included in Consolidated Statements of Operations and Comprehensive Loss

The following table summarizes the total stock-based compensation expense included in the statements of operations and comprehensive loss for all periods presented (in thousands):

	Year Ended December 31
	2021		2020		2019
Cost of revenue	$	1,896	$	27	$	658
Research and development	5,565		7,727		4,462
Selling, general and administrative	47,066		33,761		21,121
Total stock-based compensation expense	$	54,527	$	41,515	$	26,241