Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Summary of Dilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	5,764,407	9,933,787	5,218,791	9,933,787
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	2,876,703	5,081,890	2,700,275	5,081,890
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	2,741,221	3,805,547	2,372,049	3,805,547
Unvested PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	146,483	1,046,350	146,467	1,046,350