Segment Information (Tables)

9 Months Ended

Sep. 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 Sept. 30, 2014
Operating revenues (a)	$	216,289	$	14,484		$	273	$	—		$	231,046
Intersegment revenues	93		425			—		(518		)	—
Total revenues	$	216,382	$	14,909		$	273	$	(518	)	$	231,046
Net income (loss)	$	21,227	$	(2,003	)	$	806	$	—		$	20,030

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas			All Other		Reconciling Eliminations			Consolidated Total
Three Months Ended Sept. 30, 2013
Operating revenues (a)	$	216,545	$	14,266		$	249	$	—		$	231,060
Intersegment revenues	89		962			—		(1,051		)	—
Total revenues	$	216,634	$	15,228		$	249	$	(1,051	)	$	231,060
Net income (loss)	$	22,859	$	(1,726	)	$	880	$	—		$	22,013

^(a)  Operating revenues include $33 million and $36 million of affiliate electric revenue for the three months ended Sept. 30, 2014 and 2013, respectively.

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Nine Months Ended Sept. 30, 2014
Operating revenues (a)	$	625,663	$	117,814	$	825	$	—		$	744,302
Intersegment revenues	308		4,191		—		(4,499		)	—
Total revenues	$	625,971	$	122,005	$	825	$	(4,499	)	$	744,302
Net income	$	48,092	$	5,565	$	2,630	$	—		$	56,287

(Thousands of Dollars)	Regulated Electric		Regulated Natural Gas		All Other		Reconciling Eliminations			Consolidated Total
Nine Months Ended Sept. 30, 2013
Operating revenues (a)	$	592,730	$	89,178	$	742	$	—		$	682,650
Intersegment revenues	250		1,549		—		(1,799		)	—
Total revenues	$	592,980	$	90,727	$	742	$	(1,799	)	$	682,650
Net income	$	46,530	$	4,100	$	1,612	$	—		$	52,242

^(a)  Operating revenues include $97 million and $101 million of affiliate electric revenue for the nine months ended Sept. 30, 2014 and 2013, respectively.