Stock-Based Compensation - Restricted Stock Units (Details) - Restricted stock units shares in Thousands	9 Months Ended
	Sep. 30, 2021 $ / shares shares
Shares
Balance (in shares) | shares	4,188
Granted (in shares) | shares	1,528
Vested (in shares) | shares	(1,707)
Canceled/Forfeited (in shares) | shares	(227)
Balance (in shares) | shares	3,782
Weighted Average Grant Date Fair Value
Balance (in dollars per share) | $ / shares	$ 34.02
Granted (in dollars per share) | $ / shares	104.48
Vested (in dollars per share) | $ / shares	25.83
Canceled/Forfeited (in dollars per share) | $ / shares	49.39
Balance (in dollars per share) | $ / shares	$ 64.78