Segment Information (Tables)

6 Months Ended

Jun. 30, 2013

Segment Reporting [Abstract]

Results from Continuing Operations by Reportable Segment

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Three Months Ended June 30, 2013
Operating revenues	$	185,374	$	24,555	$	246	$	—		$	210,175
Intersegment revenues	83		278		—		(361		)	—
Total revenues	$	185,457	$	24,833	$	246	$	(361	)	$	210,175
Net income	$	10,068	$	201	$	275	$	—		$	10,544

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas			All Other		Reconciling Eliminations			Consolidated Total
Three Months Ended June 30, 2012
Operating revenues	$	179,105	$	14,830		$	238	$	—		$	194,173
Intersegment revenues	109		61			—		(170		)	—
Total revenues	$	179,214	$	14,891		$	238	$	(170	)	$	194,173
Net income (loss)	$	6,127	$	(947	)	$	562	$	—		$	5,742

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Six Months Ended June 30, 2013
Operating revenues	$	376,185	$	74,912	$	493	$	—		$	451,590
Intersegment revenues	161		586		—		(747		)	—
Total revenues	$	376,346	$	75,498	$	493	$	(747	)	$	451,590
Net income	$	23,671	$	5,825	$	733	$	—		$	30,229

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Six Months Ended June 30, 2012
Operating revenues	$	361,106	$	56,322	$	544	$	—		$	417,972
Intersegment revenues	196		264		—		(460		)	—
Total revenues	$	361,302	$	56,586	$	544	$	(460	)	$	417,972
Net income	$	17,375	$	2,453	$	792	$	—		$	20,620