Supplemental Oil and Gas Information (Unaudited) - Schedule of Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property acquisition costs
Unproved	$ 8.0	$ 8.5	$ 1.8
Proved	0.0	27.1	128.5
Total acquisition costs	8.0	35.6	130.3
Exploration costs	145.9	198.1	113.3
Development costs	781.5	880.8	917.7
Total costs incurred	935.4	1,114.5	1,161.3
Charged to expense
Dry hole expense	73.2	169.8	82.1
Geophysical and other costs	50.8	54.1	37.7
Total charged to expense	124.0	223.9	119.8
Property additions	811.4	890.6	1,041.5
United States - Offshore
Property acquisition costs
Unproved	7.8	0.0	1.8
Proved	0.0	12.8	128.5
Total acquisition costs	7.8	12.8	130.3
Exploration costs	85.3	157.8	42.2
Development costs	598.7	667.2	704.9
Total costs incurred	691.8	837.8	877.4
Charged to expense
Dry hole expense	70.9	153.1	23.0
Geophysical and other costs	19.2	13.4	15.8
Total charged to expense	90.1	166.5	38.8
Property additions	601.7	671.3	838.6
Canada
Property acquisition costs
Unproved	0.2	0.0	0.0
Proved	0.0	0.0	0.0
Total acquisition costs	0.2	0.0	0.0
Exploration costs	0.4	0.4	0.8
Development costs	137.7	206.2	208.5
Total costs incurred	138.3	206.6	209.3
Charged to expense
Dry hole expense	0.0	0.0	0.0
Geophysical and other costs	0.4	0.4	0.8
Total charged to expense	0.4	0.4	0.8
Property additions	137.9	206.2	208.5
Other
Property acquisition costs
Unproved	0.0	8.5	0.0
Proved	0.0	14.3	0.0
Total acquisition costs	0.0	22.8	0.0
Exploration costs	60.2	39.9	70.3
Development costs	45.1	7.4	4.3
Total costs incurred	105.3	70.1	74.6
Charged to expense
Dry hole expense	2.3	16.7	59.1
Geophysical and other costs	31.2	40.3	21.1
Total charged to expense	33.5	57.0	80.2
Property additions	$ 71.8	$ 13.1	$ (5.6)