Share-Based Compensation - Valuation Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock options
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)	0.50%	0.30%	1.60%
Risk-free interest rate, maximum (as a percent)	1.20%	1.70%	2.50%
Expected term (in years)			6 years
Expected volatility, minimum (as a percent)	52.00%	50.00%	51.00%
Expected volatility, maximum (as a percent)	53.00%	53.00%	53.00%
Weighted-average estimated fair value (in dollars per share)	$ 9.25	$ 11.03	$ 10.20
Minimum | Stock options
Weighted-average assumptions
Expected term (in years)	5 years 3 months 18 days	5 years 2 months 12 days
Maximum | Stock options
Weighted-average assumptions
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days
2013 Employee Share Purchase Plan
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)	0.03%	0.10%	1.50%
Risk-free interest rate, maximum (as a percent)	0.20%	0.20%	2.40%
Expected volatility, minimum (as a percent)	40.00%	53.00%	40.00%
Expected volatility, maximum (as a percent)	79.00%	76.00%	48.00%
Weighted-average estimated fair value (in dollars per share)	$ 3.52	$ 8.04	$ 6.17
2013 Employee Share Purchase Plan | Minimum
Weighted-average assumptions
Expected term (in years)	6 months	6 months	6 months
2013 Employee Share Purchase Plan | Maximum
Weighted-average assumptions
Expected term (in years)	2 years	2 years	2 years