Weighted Average Shares Outstanding and Net Loss Per Share - Summary of Reconciliation of Weighted Average Shares Outstanding in Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net loss allocated to common shareholders for basic calculation	$ (34,574)	$ (11,423)
Weighted average common shares outstanding, basic	46,699	39,908
Dilutive effect of RSUs	0	0
Weighted average common shares outstanding, diluted	46,699	39,908
Net loss per share, basic	$ (0.74)	$ (0.29)
Net loss per share, diluted	$ (0.74)	$ (0.29)