Segment Information (Tables)

6 Months Ended

Jun. 30, 2014

Segment Reporting [Abstract]

Results by Reportable Segment

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas			All Other		Reconciling Eliminations			Consolidated Total
Three Months Ended June 30, 2014
Operating revenues (a)	$	198,277	$	29,539		$	298	$	—		$	228,114
Intersegment revenues	123		849			—		(972		)	—
Total revenues	$	198,400	$	30,388		$	298	$	(972	)	$	228,114
Net income (loss)	$	11,799	$	(141	)	$	364	$	—		$	12,022

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Three Months Ended June 30, 2013
Operating revenues (a)	$	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

^(a)  Operating revenues include $33 million of affiliate electric revenue for the three months ended June 30, 2014 and 2013.

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Six Months Ended June 30, 2014
Operating revenues (a)	$	409,374	$	103,330	$	552	$	—		$	513,256
Intersegment revenues	215		3,766		—		(3,981		)	—
Total revenues	$	409,589	$	107,096	$	552	$	(3,981	)	$	513,256
Net income	$	26,865	$	7,568	$	1,824	$	—		$	36,257

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Six Months Ended June 30, 2013
Operating revenues (a)	$	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

^(a)  Operating revenues include $63 million and $65 million of affiliate electric revenue for the six months ended June 30, 2014 and 2013, respectively.