Business Segments - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI	$ 139,700	$ 277,800	$ 91,900	$ 214,300	$ 220,600	$ 574,100	$ 409,500	$ (65,500)	$ 723,681	$ 1,138,719	$ 47,528
Revenues from external customers									3,460,147	3,932,662	2,299,281
Interest and other income (loss)									(8,587)	14,310	(16,771)
Interest expense, net of capitalization									(112,373)	(150,759)	(221,773)
Income tax expense (benefit)									195,921	309,464	(5,862)
Impairment of assets									0	0	196,296
Depreciation, depletion and amortization									861,602	776,817	795,105
Accretion of asset retirement obligations									46,059	46,243	46,613
Amortization of undeveloped leases									10,925	13,300	18,925
Deferred and noncurrent income taxes									179,823	286,079	(4,146)
Additions to property, plant, equipment									914,800	1,063,300	585,300
Total assets at year-end	9,766,697				10,308,952				9,766,697	10,308,952	10,304,900
Minimum
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers									3,460,200
Income tax expense (benefit)									196,000
Depreciation, depletion and amortization									861,500
Total assets at year-end	9,766,600								9,766,600
Discontinued Operations
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI									(1,500)	(2,100)	(1,200)
Revenues from external customers									0	0	0
Interest and other income (loss)									0	0	0
Interest expense, net of capitalization									0	0	0
Income tax expense (benefit)									0	0	0
Impairment of assets											0
Depreciation, depletion and amortization									0	0	0
Accretion of asset retirement obligations									0	0	0
Amortization of undeveloped leases									0	0	0
Deferred and noncurrent income taxes									0	0	0
Additions to property, plant, equipment									0	0	0
Total assets at year-end	800				800				800	800	800
Corporate and Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI									(156,000)	(438,300)	(668,000)
Revenues from external customers									3,400	(314,400)	(519,400)
Interest and other income (loss)									(3,000)	23,300	(6,500)
Interest expense, net of capitalization									(111,900)	(150,400)	(221,600)
Income tax expense (benefit)									(41,800)	(107,800)	(178,600)
Impairment of assets											7,000
Depreciation, depletion and amortization									11,000	12,900	13,000
Accretion of asset retirement obligations									100	0	0
Amortization of undeveloped leases									0	0	0
Deferred and noncurrent income taxes									(50,600)	(112,000)	(170,500)
Additions to property, plant, equipment									24,200	21,900	0
Total assets at year-end	365,500				1,034,600				365,500	1,034,600	1,220,800
Exploration and Production | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI									881,200	1,579,100	716,700
Revenues from external customers									3,456,800	4,247,100	2,818,700
Interest and other income (loss)									(5,600)	(9,000)	(10,300)
Interest expense, net of capitalization									(500)	(400)	(200)
Income tax expense (benefit)									237,800	417,300	172,700
Impairment of assets											189,300
Depreciation, depletion and amortization									850,500	763,900	782,100
Accretion of asset retirement obligations									46,000	46,200	46,600
Amortization of undeveloped leases									10,900	13,300	18,900
Deferred and noncurrent income taxes									230,400	398,100	166,400
Additions to property, plant, equipment									890,600	1,041,400	585,300
Total assets at year-end	9,400,200				9,273,600				9,400,200	9,273,600	9,083,300
Exploration and Production | Operating Segments | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI									905,100	1,521,900	766,300
Revenues from external customers									2,928,300	3,461,200	2,337,500
Interest and other income (loss)									(3,900)	(6,600)	(11,600)
Interest expense, net of capitalization									(100)	(100)	0
Income tax expense (benefit)									232,700	370,800	183,900
Impairment of assets											0
Depreciation, depletion and amortization									706,000	617,000	616,500
Accretion of asset retirement obligations									37,800	36,500	36,900
Amortization of undeveloped leases									8,100	8,700	11,100
Deferred and noncurrent income taxes									229,600	362,700	176,300
Additions to property, plant, equipment									671,300	838,600	519,500
Total assets at year-end	7,107,000				6,930,600				7,107,000	6,930,600	6,591,600
Exploration and Production | Operating Segments | Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI									41,600	134,200	(16,100)
Revenues from external customers									517,500	762,900	476,300
Interest and other income (loss)									(1,100)	(1,900)	(1,900)
Interest expense, net of capitalization									(200)	0	0
Income tax expense (benefit)									11,200	43,600	(1,700)
Impairment of assets											171,300
Depreciation, depletion and amortization									142,200	141,500	163,800
Accretion of asset retirement obligations									7,800	9,600	9,700
Amortization of undeveloped leases									100	200	200
Deferred and noncurrent income taxes									7,500	34,800	(1,900)
Additions to property, plant, equipment									206,200	208,500	52,700
Total assets at year-end	2,080,000				2,125,600				2,080,000	2,125,600	2,231,900
Exploration and Production | Operating Segments | Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Segment income (loss) - including NCI									(65,500)	(77,000)	(33,500)
Revenues from external customers									11,000	23,000	4,900
Interest and other income (loss)									(600)	(500)	3,200
Interest expense, net of capitalization									(200)	(300)	(200)
Income tax expense (benefit)									(6,100)	2,900	(9,500)
Impairment of assets											18,000
Depreciation, depletion and amortization									2,300	5,400	1,800
Accretion of asset retirement obligations									400	100	0
Amortization of undeveloped leases									2,700	4,400	7,600
Deferred and noncurrent income taxes									(6,700)	600	(8,000)
Additions to property, plant, equipment									13,100	(5,700)	13,100
Total assets at year-end	$ 213,300				$ 217,400				$ 213,300	$ 217,400	$ 259,800