CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net income	$ 136	$ 125	$ 108
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	173	159	148
Deferred income taxes	(12)	(2)	9
Allowance for equity funds used during construction	(10)	(7)	(5)
Provision for bad debts	4	4	4
Changes in operating assets and liabilities:
Accounts receivable	(4)	(13)	(5)
Accrued unbilled revenues	11	(5)	(16)
Inventories	(6)	(14)	(12)
Other current assets	21	(20)	(4)
Accounts payable	(6)	5	8
Net regulatory assets and liabilities	44	18	(41)
Other current liabilities	2	16	2
Pension and other employee benefit obligations	0	(4)	(9)
Other, net	4	(5)	(1)
Net cash provided by operating activities	357	257	186
Investing activities
Capital/construction expenditures	(456)	(353)	(264)
Investments In Utility Money Pool Arrangement	(153)	(100)	(71)
Repayments From Utility Money Pool Arrangement	153	100	71
Net cash used in investing activities	(456)	(353)	(264)
Financing activities
Proceeds from (repayments of) short-term borrowings, net	13	(35)	64
Borrowings under money pool arrangement	163	591	358
Repayments under money pool arrangement	(163)	(591)	(358)
Proceeds from issuance of long-term debt	124	99	99
Repayments of long-term debt	0	0	(19)
Capital contributions from parent	75	114	46
Dividends paid to parent	(109)	(91)	(103)
Net cash provided by financing activities	103	87	87
Net change in cash, cash equivalents and restricted cash	4	(9)	9
Cash, cash equivalents and restricted cash at beginning of period	2	11	2
Cash, cash equivalents and restricted cash at end of period	6	2	11
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(47)	(39)	(38)
Cash paid for income taxes, net	(40)	(32)	(22)
Other Noncash Investing and Financing Items [Abstract]
Supplemental disclosure of non-cash investing and financing transactions:	31	54	43
Inventory transfers to plant, property and equipment	17	1	1
Allowance for Funds Used During Construction, Investing Activities	$ 10	$ 7	$ 5