Summary of Significant Accounting Policies - Summary of reconciliation of shares used to determine net (loss) income per share (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies
Net income (loss)	$ (25,940)	$ (55,659)
Weighted average number of shares - basic	42,613,478	42,484,972
Weighted average number of shares outstanding - diluted	42,613,478	42,484,972