Net Income/(Loss) Per Share - Antidilutive Shares (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	22,923	6,941	22,923	6,941
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	1,125		1,125
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	12,751	579	12,751	579
Restricted stock units ("RSUs")
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	5,889	8	5,889	8
Performance stock options ("PSOs")
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	2,800	3,382	2,800	3,382
Performance stock units ("PSUs")
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share		2,972		2,972
Employee stock purchase plan ("ESPP")
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	358		358