Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Cost	$ 20,585,703	$ 19,724,343
Net	8,127,852	8,269,038
Exploration and Production
Property, Plant and Equipment [Line Items]
Cost	20,440,568	19,583,682
Net	8,098,396	8,232,191
Corporate and other
Property, Plant and Equipment [Line Items]
Cost	145,135	140,661
Net	29,456	36,847
Mineral Rights
Property, Plant and Equipment [Line Items]
Cost	615,724	649,704
Net	131,107	530,194
Administrative Assets and Support Equipment
Property, Plant and Equipment [Line Items]
Net	$ 22,543	$ 22,940