RELATED PARTY TRANSACTIONS (Summary of Related Party Transactions) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Transactions under commercial agreements:
Sales	$ 12,132.8	$ 7,651.1	$ 31,715.4	$ 22,192.8
St. Bernard Renewables LLC \| Equity Method Investment, Nonconsolidated Investee or Group of Investees
Transactions under commercial agreements:
Sales	53.9	10.8	108.3	41.1
Purchases	(378.2)	(132.2)	(788.7)	(313.8)
St. Bernard Renewables LLC \| Equity Method Investment, Nonconsolidated Investee or Group of Investees \| General and Administrative Expense \| Operating agreement
Reimbursements under related party agreements:
Transactions with related party	31.1	30.2	133.0	104.6
St. Bernard Renewables LLC \| Equity Method Investment, Nonconsolidated Investee or Group of Investees \| General and Administrative Expense \| Omnibus agreement
Reimbursements under related party agreements:
Transactions with related party	1.1	1.0	3.0	2.9
St. Bernard Renewables LLC \| Equity Method Investment, Nonconsolidated Investee or Group of Investees \| General and Administrative Expense \| Common asset use and servitude agreement
Reimbursements under related party agreements:
Transactions with related party	1.9	1.9	5.6	5.9
St. Bernard Renewables LLC \| Equity Method Investment, Nonconsolidated Investee or Group of Investees \| Cost of Sales \| Lease Agreements
Reimbursements under related party agreements:
Transactions with related party	$ 0.0	$ 0.0	$ 0.0	$ (8.1)