v3.26.1
PROPERTY, PLANT AND EQUIPMENT (Details)
$ in Millions
6 Months Ended
Jun. 30, 2026
USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Beginning Balance $ 3,712
Accretion Expense 87
Liabilities Incurred 3
Liabilities Settled (43)
Revisions in Cash Flow Estimates 42
Ending Balance 3,801
PUBLIC SERVICE COMPANY OF OKLAHOMA  
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Beginning Balance 143
Accretion Expense 4
Liabilities Incurred 0
Liabilities Settled (3)
Revisions in Cash Flow Estimates 19
Ending Balance $ 163