Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Allocation (Details Textual) - USD ($) $ in Millions	1 Months Ended		11 Months Ended	12 Months Ended
Allocation (Details Textual) - USD ($) $ in Millions	Jun. 30, 2017	Jun. 26, 2017	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Allocated Share-based Compensation Expense			$ 0.1	$ 0.2	$ 0.3
Share Based Compensation Allocation Percentage	100.00%
IPO [Member]
Allocated Share-based Compensation Expense		$ 0.6
Research and Development Expense [Member]
Share Based Compensation Allocation Percentage				50.00%
General and Administrative Expense [Member]
Share Based Compensation Allocation Percentage				50.00%