Basis of Presentation, Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Loss Per Share (Details) - shares	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Net Earnings per Share
Securities excluded from diluted loss per share calculation	9,898,322	7,361,001
Employee stock options
Net Earnings per Share
Securities excluded from diluted loss per share calculation	8,289,605	6,881,001
Restricted stock awards
Net Earnings per Share
Securities excluded from diluted loss per share calculation	146,800	480,000
Restricted stock units
Net Earnings per Share
Securities excluded from diluted loss per share calculation	1,461,917

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://www.xbrl.org/2003/role/presentationRef
-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