SUPPLEMENTAL OIL AND GAS DISCLOSURES (UNAUDITED) - Standardized Measure of Discounted Future Net Cash Flows (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2019
Standardized Measure of Discounted Future Net Cash Flows
Future cash inflows	$ 4,282.3	$ 8,856.0	$ 5,178.0
Production	(2,007.6)	(2,895.0)	(2,062.0)
Development and abandonment	(1,052.3)	(990.0)	(976.0)
Income taxes	(210.3)	(1,006.0)	(359.0)
Future net cash inflows	1,012.1	3,965.0	1,781.0
10% annual discount factor	(328.9)	(1,702.0)	(625.0)
Total	$ 683.2	$ 2,263.0	$ 1,156.0	$ 493.7