CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating activities
Net income	$ 134	$ 136	$ 125
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	189	173	159
Deferred income taxes	0	(12)	(2)
Allowance for equity funds used during construction	(16)	(10)	(7)
Provision for bad debts	2	4	4
Changes in operating assets and liabilities:
Accounts receivable	(27)	(4)	(13)
Accrued unbilled revenues	2	11	(5)
Inventories	(12)	(6)	(14)
Other current assets	(7)	21	(20)
Accounts payable	(2)	(6)	5
Net regulatory assets and liabilities	25	44	18
Other current liabilities	3	2	16
Pension and other employee benefit obligations	(8)	0	(4)
Other, net	2	4	(5)
Net cash provided by operating activities	285	357	257
Investing activities
Capital/construction expenditures	(550)	(456)	(353)
Investments In Utility Money Pool Arrangement	(15)	(153)	(100)
Repayments From Utility Money Pool Arrangement	0	153	100
Net cash used in investing activities	(565)	(456)	(353)
Financing activities
(Repayments of) proceeds from short-term borrowings, net	(25)	13	(35)
Borrowings under money pool arrangement	170	163	591
Repayments under money pool arrangement	(170)	(163)	(591)
Proceeds from issuance of long-term debt	394	124	99
Repayments of long-term debt	(200)	0	0
Capital contributions from parent	211	75	114
Dividends paid to parent	(98)	(109)	(91)
Net cash provided by financing activities	282	103	87
Net change in cash, cash equivalents and restricted cash	2	4	(9)
Cash, cash equivalents and restricted cash at beginning of period	6	2	11
Cash, cash equivalents and restricted cash at end of period	8	6	2
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(55)	(47)	(39)
Cash paid for income taxes, net	(36)	(40)	(32)
Other Noncash Investing and Financing Items [Abstract]
Supplemental disclosure of non-cash investing and financing transactions:	36	31	54
Inventory transfers to plant, property and equipment	13	17	1
Allowance for Funds Used During Construction, Investing Activities	$ 16	$ 10	$ 7