Net Loss Per Share - Antidilutive (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	19,284,802	19,614,385
Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	2,672,864	3,744,631
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	14,372,988	14,904,876
Performance Stock Units (PSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	1,005,000
ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	519,358	491,151
Stock-settled bonus shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	714,592	473,727