Segments and Related Information (Tables)

12 Months Ended

Dec. 31, 2012

Segments and Related Information [Abstract]

Results from Continuing Operations by Reportable Segment

	Regulated		Regulated		All			Reconciling			Consolidated
(Thousands of Dollars)	Electric		Natural Gas		Other			Eliminations			Total
2012
Operating revenues	$	757,565	$	103,100	$	1,177		$	-		$	861,842
Intersegment revenues		355		727		-			(1,082	)		-
Total revenues	$	757,920	$	103,827	$	1,177		$	(1,082	)	$	861,842
Depreciation and amortization	$	59,768	$	9,251	$	215		$	-		$	69,234
Interest charges and financing cost		20,303		2,554		80			-			22,937
Income tax expense		27,164		2,113		281			-			29,558
Net income		45,377		3,094		1,480			-			49,951
2011
Operating revenues	$	755,136	$	119,447	$	1,207		$	-		$	875,790
Intersegment revenues		405		1,581		-			(1,986	)		-
Total revenues	$	755,541	$	121,028	$	1,207		$	(1,986	)	$	875,790
Depreciation and amortization	$	58,800	$	9,599	$	175		$	-		$	68,574
Interest charges and financing cost		21,181		2,675		137			-			23,993
Income tax expense (benefit)		32,656		1,995		(1,037	)		-			33,614
Net income		47,093		2,964		949			-			51,006
2010
Operating revenues	$	708,179	$	118,076	$	1,036		$	-		$	827,291
Intersegment revenues		360		1,122		-			(1,482	)		-
Total revenues	$	708,539	$	119,198	$	1,036		$	(1,482	)	$	827,291
Depreciation and amortization	$	54,414	$	9,037	$	218		$	-		$	63,669
Interest charges and financing cost		20,738		2,597		143			-			23,478
Income tax expense (benefit)		24,819		1,836		(543	)		-			26,112
Net income		37,773		3,325		1,651			-			42,749