Earnings Per Share - Schedule of Potentially Issuable Common Shares not Included in Computation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	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 common stock instruments outstanding (shares)	9,127	8,109	9,127	8,109
Shares issuable upon the release of restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common stock instruments outstanding (shares)	25	16	25	16
Shares issuable upon exercise of stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common stock instruments outstanding (shares)	9,102	8,093	9,102	8,093