Share Based Payments - Schedule of Fair Value of Employee and Director Stock Options Granted Estimated Using Black-Scholes Option Pricing Model With Following Weighted Average Assumptions (Details) - Employee and Director Stock Options - $ / shares	9 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock price	$ 6.95	$ 10.40
Exercise price	$ 6.95	$ 10.85
Expected term	2 years 6 months	6 years 3 months
Expected volatility	77.92%	90.84%
Risk-free interest rate	0.49%	1.06%
Dividend rate	0.00%	0.00%