Stock-Based Compensation - Summary of RSU Activity (Details) - RSUs shares in Thousands	9 Months Ended
	Sep. 30, 2021 $ / shares shares
Number of Share Units
Share Units, Outstanding as of December 31, 2020 | shares	4,061
Share Units, Granted | shares	1,626
Share Units, Vested and delivered | shares	(1,578)
Share Units, Forfeited | shares	(275)
Share Units, Outstanding as of September 30, 2021 | shares	3,834	[1]
Weighted-Average Grant Date Fair Value
Weighted-Average Grant Date Fair Value, Outstanding as of December 31, 2020 | $ / shares	$ 8.31
Weighted-Average Grant Date Fair Value, Granted | $ / shares	14.98
Weighted-Average Grant Date Fair Value, Vested and delivered | $ / shares	8.46
Weighted-Average Grant Date Fair Value, Forfeited | $ / shares	9.65
Weighted-Average Grant Date Fair Value, Outstanding as of September 30, 2021 | $ / shares	$ 10.98	[1]

[1] Included in “Outstanding as of September 30, 2021” are 63 RSUs that were vested, but not yet delivered.