Net Income/(Loss) Per Share - Antidilutive Shares (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities excluded from computation of diluted net loss per share	24,776	6,479
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
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	13,641	277
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	6,338
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	3,244	3,244
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	428