Business Segments (Details) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Revenue from contracts with customers	$ 672,730,000	$ 794,848,000
Gain on sales of assets and other operating income	(7,000,000.0)	1,600,000
Total revenues and other income	665,711,000	796,412,000
Lease operating expenses and taxes other than income	145,900,000	167,100,000
Repair and maintenance	11,800,000	11,600,000
Workovers	47,400,000	55,600,000
Total lease operating expenses	205,079,000	234,264,000
Severance and ad valorem taxes	8,650,000	10,086,000
Transportation, gathering and processing	48,851,000	56,553,000
Costs of purchased natural gas	0	160,000
Selling and general expenses	30,900,000	31,100,000
Geological and geophysical	3,500,000	1,400,000
Dry holes and previously suspended exploration costs	200,000	32,400,000
Other exploratory costs, including undeveloped lease amortization and delay lease rentals	10,800,000	10,600,000
Total exploration expenses	14,488,000	44,429,000
Depreciation, depletion and amortization	194,200,000	211,100,000
Impairment of assets	0	34,528,000
Accretion of asset retirement obligations	14,045,000	12,774,000
Other operating expenses	5,600,000	7,300,000
Interest Income	(3,700,000)	(3,600,000)
Interest (expense), net of capitalization	23,523,000	20,021,000
Current income tax expense	16,300,000	10,700,000
Deferred income tax expense (benefit)	16,400,000	19,400,000
Total income tax expense	32,700,000	30,100,000
Other segment items	1,900,000	(7,200,000)
Net income including noncontrolling interest	89,418,000	114,658,000
Additions to property, plant, equipment	412,000,000.0	229,600,000
Total assets at quarter-end	9,820,323,000	9,668,700,000	$ 9,667,479,000
Revenue from production
Segment Reporting Information [Line Items]
Revenue from contracts with customers	672,730,000	794,603,000
Sales of purchased natural gas
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	245,000
Operating Segments
Segment Reporting Information [Line Items]
Gain on sales of assets and other operating income	2,500,000	1,600,000
Total revenues and other income	675,200,000	796,400,000
Lease operating expenses and taxes other than income	145,900,000	167,100,000
Repair and maintenance	11,800,000	11,600,000
Workovers	47,400,000	55,600,000
Total lease operating expenses	205,100,000	234,300,000
Severance and ad valorem taxes	8,700,000	10,100,000
Transportation, gathering and processing	48,900,000	56,500,000
Costs of purchased natural gas	0	200,000
Selling and general expenses	9,900,000	6,100,000
Geological and geophysical	3,500,000	1,400,000
Dry holes and previously suspended exploration costs	200,000	32,400,000
Other exploratory costs, including undeveloped lease amortization and delay lease rentals	10,800,000	10,600,000
Total exploration expenses	14,500,000	44,400,000
Depreciation, depletion and amortization	191,900,000	208,300,000
Impairment of assets		34,500,000
Accretion of asset retirement obligations	14,000,000.0	12,800,000
Other operating expenses	3,600,000	7,300,000
Interest Income	(400,000)	(700,000)
Interest (expense), net of capitalization	0	100,000
Current income tax expense	14,200,000	6,800,000
Deferred income tax expense (benefit)	25,100,000	30,600,000
Total income tax expense	39,300,000	37,400,000
Other segment items	1,500,000	2,000,000.0
Net income including noncontrolling interest	138,200,000	143,100,000
Additions to property, plant, equipment	407,800,000	225,400,000
Total assets at quarter-end	9,355,400,000	9,300,000,000
Operating Segments | United States
Segment Reporting Information [Line Items]
Gain on sales of assets and other operating income	2,100,000	1,200,000
Total revenues and other income	509,500,000	659,600,000
Lease operating expenses and taxes other than income	100,300,000	120,200,000
Repair and maintenance	10,200,000	11,000,000.0
Workovers	47,100,000	55,400,000
Total lease operating expenses	157,600,000	186,600,000
Severance and ad valorem taxes	8,400,000	9,800,000
Transportation, gathering and processing	28,700,000	36,600,000
Costs of purchased natural gas	0	0
Selling and general expenses	2,000,000.0	(200,000)
Geological and geophysical	3,200,000	600,000
Dry holes and previously suspended exploration costs	200,000	31,200,000
Other exploratory costs, including undeveloped lease amortization and delay lease rentals	2,700,000	3,400,000
Total exploration expenses	6,100,000	35,200,000
Depreciation, depletion and amortization	159,400,000	174,000,000.0
Impairment of assets		34,500,000
Accretion of asset retirement obligations	11,300,000	10,400,000
Other operating expenses	2,600,000	6,300,000
Interest Income	(400,000)	(700,000)
Interest (expense), net of capitalization	0	0
Current income tax expense	500,000	1,000,000.0
Deferred income tax expense (benefit)	24,500,000	29,800,000
Total income tax expense	25,000,000.0	30,800,000
Other segment items	900,000	1,800,000
Net income including noncontrolling interest	107,900,000	134,500,000
Additions to property, plant, equipment	317,100,000	155,300,000
Total assets at quarter-end	7,046,300,000	7,030,700,000
Operating Segments | Canada
Segment Reporting Information [Line Items]
Gain on sales of assets and other operating income	400,000	400,000
Total revenues and other income	165,700,000	136,900,000
Lease operating expenses and taxes other than income	45,200,000	46,700,000
Repair and maintenance	1,600,000	600,000
Workovers	300,000	200,000
Total lease operating expenses	47,100,000	47,500,000
Severance and ad valorem taxes	300,000	300,000
Transportation, gathering and processing	20,200,000	19,900,000
Costs of purchased natural gas	0	200,000
Selling and general expenses	6,000,000.0	5,100,000
Geological and geophysical	0	0
Dry holes and previously suspended exploration costs	0	0
Other exploratory costs, including undeveloped lease amortization and delay lease rentals	100,000	100,000
Total exploration expenses	100,000	100,000
Depreciation, depletion and amortization	32,400,000	34,300,000
Impairment of assets		0
Accretion of asset retirement obligations	2,500,000	2,100,000
Other operating expenses	900,000	900,000
Interest Income	0	0
Interest (expense), net of capitalization	0	100,000
Current income tax expense	13,700,000	5,800,000
Deferred income tax expense (benefit)	600,000	1,100,000
Total income tax expense	14,300,000	6,900,000
Other segment items	400,000	100,000
Net income including noncontrolling interest	41,500,000	19,400,000
Additions to property, plant, equipment	55,400,000	67,200,000
Total assets at quarter-end	1,963,400,000	2,059,100,000
Operating Segments | Other
Segment Reporting Information [Line Items]
Gain on sales of assets and other operating income	0	0
Total revenues and other income	0	(100,000)
Lease operating expenses and taxes other than income	400,000	200,000
Repair and maintenance	0	0
Workovers	0	0
Total lease operating expenses	400,000	200,000
Severance and ad valorem taxes	0	0
Transportation, gathering and processing	0	0
Costs of purchased natural gas	0	0
Selling and general expenses	1,900,000	1,200,000
Geological and geophysical	300,000	800,000
Dry holes and previously suspended exploration costs	0	1,200,000
Other exploratory costs, including undeveloped lease amortization and delay lease rentals	8,000,000.0	7,100,000
Total exploration expenses	8,300,000	9,100,000
Depreciation, depletion and amortization	100,000	0
Impairment of assets		0
Accretion of asset retirement obligations	200,000	300,000
Other operating expenses	100,000	100,000
Interest Income	0	0
Interest (expense), net of capitalization	0	0
Current income tax expense	0	0
Deferred income tax expense (benefit)	0	(300,000)
Total income tax expense	0	(300,000)
Other segment items	200,000	100,000
Net income including noncontrolling interest	(11,200,000)	(10,800,000)
Additions to property, plant, equipment	35,300,000	2,900,000
Total assets at quarter-end	345,700,000	210,200,000
Operating Segments | Revenue from production
Segment Reporting Information [Line Items]
Revenue from contracts with customers	672,700,000	794,600,000
Operating Segments | Revenue from production | United States
Segment Reporting Information [Line Items]
Revenue from contracts with customers	507,400,000	658,400,000
Operating Segments | Revenue from production | Canada
Segment Reporting Information [Line Items]
Revenue from contracts with customers	165,300,000	136,300,000
Operating Segments | Revenue from production | Other
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	(100,000)
Operating Segments | Sales of purchased natural gas
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	200,000
Operating Segments | Sales of purchased natural gas | United States
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	0
Operating Segments | Sales of purchased natural gas | Canada
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	200,000
Operating Segments | Sales of purchased natural gas | Other
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	0
Corporate, Other, and Discontinued Operations
Segment Reporting Information [Line Items]
Gain on sales of assets and other operating income	(9,500,000)	0
Total revenues and other income	(9,500,000)	0
Lease operating expenses and taxes other than income	0	0
Repair and maintenance	0	0
Workovers	0	0
Total lease operating expenses	0	0
Severance and ad valorem taxes	0	0
Transportation, gathering and processing	0	100,000
Costs of purchased natural gas	0	0
Selling and general expenses	21,000,000.0	25,000,000.0
Geological and geophysical	0	0
Dry holes and previously suspended exploration costs	0	0
Other exploratory costs, including undeveloped lease amortization and delay lease rentals	0	0
Total exploration expenses	0	0
Depreciation, depletion and amortization	2,300,000	2,800,000
Impairment of assets		0
Accretion of asset retirement obligations	0	0
Other operating expenses	2,000,000.0	0
Interest Income	(3,300,000)	(2,900,000)
Interest (expense), net of capitalization	23,500,000	19,900,000
Current income tax expense	2,100,000	3,900,000
Deferred income tax expense (benefit)	(8,700,000)	(11,200,000)
Total income tax expense	(6,600,000)	(7,300,000)
Other segment items	400,000	(9,200,000)
Net income including noncontrolling interest	(48,800,000)	(28,400,000)
Additions to property, plant, equipment	4,200,000	4,200,000
Total assets at quarter-end	464,900,000	368,700,000
Corporate, Other, and Discontinued Operations | Revenue from production
Segment Reporting Information [Line Items]
Revenue from contracts with customers	0	0
Corporate, Other, and Discontinued Operations | Sales of purchased natural gas
Segment Reporting Information [Line Items]
Revenue from contracts with customers	$ 0	$ 0