Segments and Related Information (Tables)

12 Months Ended

Dec. 31, 2020

Segment Reporting [Abstract]

Results from Operations by Reportable Segment

(Millions of Dollars)	2020		2019		2018
Regulated Electric
Operating revenues - external (a)	$	855	$	845	$	879
Intersegment revenue	1		—		—
Total revenues	$	856	$	845	$	879
Depreciation and amortization	108		109		98
Interest charges and financing costs	34		34		32
Income tax expense	12		13		28
Net income	98		68		85
Regulated Natural Gas
Total revenues	$	119	$	136	$	142
Depreciation and amortization	48		29		28
Interest charges and financing costs	4		4		3
Income tax (benefit) expense	(20)		2		5
Net income	7		10		13
All Other
Total revenues (a)	$	—	$	—	$	1
Income tax expense (benefit)	1		1		(1)
Net income	2		1		—
Consolidated Total
Total revenues (a)	$	975	$	981	$	1,022
Reconciling eliminations	(1)		—		—
Total operating revenues	$	974	$	981	$	1,022
Depreciation and amortization	156		138		126
Interest charges and financing costs	38		38		35
Income tax (benefit) expense	(7)		16		32
Net income	107		79		98

(a)    Operating revenues include $168 million, $177 million and $158 million of intercompany revenue for the years ended Dec. 31, 2020, 2019 and 2018, respectively. See Note 12 for further information.