Net Income (Loss) Per Share - Anti-dilutive Securities (Details) - shares	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Net Loss Per Share
Anti-dilutive securities (in shares)	10,920,123	14,770,633
Stock options
Net Loss Per Share
Anti-dilutive securities (in shares)	7,536,325	10,300,404
Convertibles notes
Net Loss Per Share
Anti-dilutive securities (in shares)	3,164,557	3,164,557
Restricted stock units
Net Loss Per Share
Anti-dilutive securities (in shares)	219,241	1,305,672

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration