Condensed Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Shares	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Balance at Dec. 31, 2020	$ 627,505	$ 290,115	$ (51,082)	$ 1,817,649	$ (1,429,177)
Balance (in shares) at Dec. 31, 2020		398,425,000
Balance, Treasury Shares (in shares) at Dec. 31, 2020			(5,886,919)
Exercise of stock options	$ 2,059	$ 536		1,523
Exercise of stock options (in shares)	783,320	783,320
Vesting of restricted stock units	$ (7,252)	$ 1,709	$ (7,252)	(1,709)
Vesting of restricted stock units (in shares)		2,447,405	(1,003,965)
Stock-based compensation	13,925			13,925
Loss for the period	(1,626)				(1,626)
Balance at Mar. 31, 2021	634,611	$ 292,360	$ (58,334)	1,831,388	(1,430,803)
Balance (in shares) at Mar. 31, 2021		401,655,725
Balance, Treasury Shares (in shares) at Mar. 31, 2021			(6,890,884)
Balance at Dec. 31, 2021	$ 667,099	$ 294,027	$ (60,726)	1,855,246	(1,421,448)
Balance (in shares) at Dec. 31, 2021		404,084,775
Balance, Treasury Shares (in shares) at Dec. 31, 2021	7,486,767		(7,486,767)
Exercise of stock options	$ 30	$ 6		24
Exercise of stock options (in shares)	10,602	10,602
Vesting of restricted stock units	$ (535)	$ 331	$ (535)	(331)
Vesting of restricted stock units (in shares)		493,381	(161,083)
Stock-based compensation	6,078			6,078
Loss for the period	(31,563)				(31,563)
Balance at Mar. 31, 2022	$ 641,109	$ 294,364	$ (61,261)	$ 1,861,017	$ (1,453,011)
Balance (in shares) at Mar. 31, 2022		404,588,758
Balance, Treasury Shares (in shares) at Mar. 31, 2022	7,647,850		(7,647,850)