In the following tables, revenue is classified by the type of goods/services rendered and market/customer type. The tables also reconcile revenue to the reportable segments.



	Three Months Ended Sept. 30, 2018
(Thousands of Dollars)	Electric		Natural Gas		All Other		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	67,919	$	7,021	$	12	$	74,952
Commercial and industrial (C&I)	127,936		6,818		24		134,778
Other	1,325		—		262		1,587
Total retail	197,180		13,839		298		211,317
Interchange	39,993		—		—		39,993
Other	363		940		—		1,303
Total revenue from contracts with customers	237,536		14,779		298		252,613
Alternative revenue and other	2,808		576		—		3,384
Total revenues	$	240,344	$	15,355	$	298	$	255,997



	Three Months Ended Sept. 30, 2017
(Thousands of Dollars)	Electric		Natural Gas		All Other		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	62,025	$	6,428	$	48	$	68,501
C&I	119,495		6,441		23		125,959
Other	1,329		—		244		1,573
Total retail	182,849		12,869		315		196,033
Interchange	45,916		—		—		45,916
Other	1,157		1,011		—		2,168
Total revenue from contracts with customers	229,922		13,880		315		244,117
Alternative revenue and other	2,880		514		—		3,394
Total revenues	$	232,802	$	14,394	$	315	$	247,511



	Nine Months Ended Sept. 30, 2018
(Thousands of Dollars)	Electric		Natural Gas		All Other		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	194,456	$	48,259	$	38	$	242,753
Commercial and industrial (C&I)	339,120		40,775		74		379,969
Other	4,713		—		735		5,448
Total retail	538,289		89,034		847		628,170
Interchange	116,037		—		—		116,037
Other	3,227		3,016		—		6,243
Total revenue from contracts with customers	657,553		92,050		847		750,450
Alternative revenue and other	8,659		1,786		—		10,445
Total revenues	$	666,212	$	93,836	$	847	$	760,895



	Nine Months Ended Sept. 30, 2017
(Thousands of Dollars)	Electric		Natural Gas		All Other		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	182,822	$	42,071	$	68	$	224,961
C&I	329,774		35,276		74		365,124
Other	4,527		—		705		5,232
Total retail	517,123		77,347		847		595,317
Interchange	131,259		—		—		131,259
Other	2,649		2,829		—		5,478
Total revenue from contracts with customers	651,031		80,176		847		732,054
Alternative revenue and other	8,822		1,592		—		10,414
Total revenues	$	659,853	$	81,768	$	847	$	742,468