Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2025

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

Segment information:

	Three Months Ended March 31
	2025		2024
(Millions of Dollars)	Regulated electric utility		Regulated electric utility
Operating revenues	$	521	$	428
Electric fuel and purchased power	216		160
O&M expenses	88		72
Depreciation and amortization	112		99
Other segment expenses, net	24		24
Interest charges and financing costs	43		35
Income tax benefit	(21)		(19)
Net income	$	59	$	57