Revenue from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 871,374	$ 592,527
Loss on crude contracts	(320,777)	(214,385)
Gain on sale of assets and other income	2,364	1,843
Total revenues and other income	552,961	379,985
Revenue from production
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	834,528	592,527
Net crude oil and condensate revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	702,846	490,796
Net natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	35,531	21,569
Net natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	96,151	80,162
Sales of purchased natural gas
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	36,846	0
United States | Net crude oil and condensate revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	171,696	114,490
United States | Net natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	16,685	7,528
United States | Net natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11,369	6,443
United States Offshore | Net crude oil and condensate revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	465,621	328,341
United States Offshore | Net natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	13,979	10,054
United States Offshore | Net natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	26,201	22,138
Canada     | Net crude oil and condensate revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	36,697	29,903
Canada     | Net natural gas liquids revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4,867	3,987
Canada     | Net natural gas revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	58,581	51,581
Canada Offshore | Net crude oil and condensate revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 28,832	$ 18,062