COMMITMENTS, GUARANTEES AND CONTINGENCIES - Narrative (Details)	3 Months Ended	9 Months Ended
	Jun. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) unit a uncommittedFacility
Other Commitments [Line Items]
Number of uncommitted facilities | uncommittedFacility		6
Liabilities Incurred		$ 21,200,000
Area of land closed, noncompliant with CCR rule | a		300
Cook Plant | I&M
Other Commitments [Line Items]
Nuclear contingencies, number of units | unit		2
CCR Rule Revision
Other Commitments [Line Items]
Liabilities Incurred	$ 674,000,000
Line of Credit | Revolving Credit Facility | Revolving Credit Facility, Due March 2029
Other Commitments [Line Items]
Line of credit facility, borrowing capacity		$ 5,000,000,000
Line of Credit | Revolving Credit Facility | Revolving Credit Facility, Due March 2027
Other Commitments [Line Items]
Line of credit facility, borrowing capacity		1,000,000,000
Line of Credit | Letter of Credit
Other Commitments [Line Items]
Debt instrument, face amount		450,000,000
Line of Credit | Letter of Credit | Subsidiaries
Other Commitments [Line Items]
Line of credit facility, borrowing capacity		1,200,000,000
Line of Credit | Letter of Credit | Revolving Credit Facility, Due March 2029
Other Commitments [Line Items]
Line of credit facility, borrowing capacity		0
Line of Credit | Letter of Credit | Revolving Credit Facility, Due March 2027
Other Commitments [Line Items]
Line of credit facility, borrowing capacity		$ 0