Basic and Diluted Net Loss Per Share - Schedule of Common Equivalent Shares were Excluded From Diluted Net Loss Per Share Calculation because their Inclusion would have been Anti-Dilutive (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss per share	8,772,088	5,973,473	6,679,809
Convertible Senior Notes
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss per share	6,733,914	3,411,199	3,411,199
Stock-Based Compensation Grants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from diluted net loss per share	2,038,174	2,562,274	3,268,610