Earnings (Loss) per Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic and diluted loss per share
Net loss for the period	$ (69,484)	$ (82,764)	$ (114,780)
Weighted average number of shares outstanding	12,845,089	7,419,948	5,079,576
Basic and diluted loss per share	$ (5.41)	$ (11.15)	$ (22.60)