Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Summary of activity for the Company's restricted shares

Restricted Stock Units	Shares	Weighted- Average Grant-Date Fair Value
Unvested at December 31, 2020	5,393	$	6.70
Granted	13,641	9.80
Vested	(3,684)	12.92
Forfeited	(1,533)	7.68
Unvested at December 31, 2021	13,817	$	7.99

Summary of activity for performance-based restricted stock units

The activity for performance-based restricted stock units in the year ended December 31, 2021 was as follows (in thousands, except weighted-average grant-date fair value amounts):

Performance-Based Restricted Stock Units	Shares	Weighted- Average Grant-Date Fair Value
Unvested at Unvested at December 31, 2020	1,004	$	15.58
Granted	10,034	4.03
Vested	—	—
Forfeited	—	—
Unvested at Unvested at December 31, 2021	11,038	$	5.08

Summary of Stock-Based Compensation Expense by Consolidated Statements of Operations Line Item

The following table summarizes the Company’s total stock-based compensation expense by line item for the years ended presented in the consolidated statements of operations (in thousands):

	Year ended December 31,
	2021		2020
Research and development	$	25,768	$	59,410
Selling, general and administrative	82,592		24,870
Total	$	108,360	$	84,280