CONDENSED STATEMENTS OF CASH FLOWS - PSO - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities:
Depreciation and Amortization	$ 907	$ 833
Deferred Income Taxes	188	165
Allowance for Equity Funds Used During Construction	(70)	(57)
Mark-to-Market of Risk Management Contracts	100	(15)
Property Taxes	(108)	(88)
Deferred Fuel Over/Under-Recovery, Net	(122)	(75)
Change in Other Noncurrent Assets	(351)	(131)
Change in Other Noncurrent Liabilities	433	142
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(36)	(2)
Fuel, Materials and Supplies	(39)	139
Accounts Payable	108	6
Accrued Taxes, Net	(244)	(153)
Other Current Assets	(115)	(23)
Other Current Liabilities	(66)	(93)
Net Cash Flows from Operating Activities	1,519	1,450
INVESTING ACTIVITIES
Construction Expenditures	(2,830)	(2,100)
Other Investing Activities	(1)	(5)
Net Cash Flows Used for Investing Activities	(3,569)	(2,102)
FINANCING ACTIVITIES
Retirement of Long-term Debt	(678)	(229)
Principal Payments for Finance Lease Obligations	(24)	(13)
Other Financing Activities	(29)	(18)
Net Cash Flows from (Used for) Financing Activities	2,121	698
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	71	46
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	268	246
Cash, Cash Equivalents and Restricted Cash at End of Period	339	292
SUPPLEMENTARY INFORMATION
Cash Paid for Interest, Net of Capitalized Amounts	450	350
Noncash Acquisitions Under Finance Leases	24	8
Construction Expenditures Included in Current Liabilities as of March 31,	1,434	1,041
PUBLIC SERVICE COMPANY OF OKLAHOMA
OPERATING ACTIVITIES
Net Income	15	28
Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities:
Depreciation and Amortization	73	69
Deferred Income Taxes	6	40
Allowance for Equity Funds Used During Construction	(3)	(3)
Mark-to-Market of Risk Management Contracts	28	(17)
Property Taxes	(58)	(45)
Deferred Fuel Over/Under-Recovery, Net	(21)	(76)
Change in Other Noncurrent Assets	(17)	(9)
Change in Other Noncurrent Liabilities	138	19
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(46)	2
Fuel, Materials and Supplies	(6)	5
Accounts Payable	(13)	(10)
Accrued Taxes, Net	(20)	(1)
Other Current Assets	(3)	(2)
Other Current Liabilities	(58)	(30)
Net Cash Flows from Operating Activities	15	(30)
INVESTING ACTIVITIES
Construction Expenditures	(331)	(168)
Change in Advances to Affiliates, Net	0	232
Other Investing Activities	1	1
Net Cash Flows Used for Investing Activities	(330)	65
FINANCING ACTIVITIES
Change in Advances from Affiliates, Net	316	91
Retirement of Long-term Debt	0	(125)
Principal Payments for Finance Lease Obligations	(1)	(1)
Other Financing Activities	0	1
Net Cash Flows from (Used for) Financing Activities	315	(34)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	0	1
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	2	2
Cash, Cash Equivalents and Restricted Cash at End of Period	2	3
SUPPLEMENTARY INFORMATION
Cash Paid for Interest, Net of Capitalized Amounts	69	34
Noncash Acquisitions Under Finance Leases	1	1
Construction Expenditures Included in Current Liabilities as of March 31,	$ 131	$ 73