Segment Information (Tables)

6 Months Ended

Jun. 30, 2015

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, 2015
Operating revenues (a)	$	199,621	$	16,889		$	303		$	—		$	216,813
Intersegment revenues	98		73			—			(171		)	—
Total revenues	$	199,719	$	16,962		$	303		$	(171	)	$	216,813
Net income (loss)	$	13,787	$	(1,074	)	$	(201	)	$	—		$	12,512

(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

^(a)  Operating revenues include $33 million of affiliate electric revenue for the three months ended June 30, 2015 and 2014.

(Thousands of Dollars)	Regulated Electric			Regulated Natural Gas		All Other			Reconciling Eliminations			Consolidated Total
Six Months Ended June 30, 2015
Operating revenues (a)	$	409,905		$	80,185	$	683		$	—		$	490,773
Intersegment revenues	207			298		—			(505		)	—
Total revenues	$	410,112		$	80,483	$	683		$	(505	)	$	490,773
Net income (loss)	$	29,301	(b)	$	5,707	$	(229	)	$	—		$	34,779

(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

^(a)  Operating revenues include $78 million and $63 million of affiliate electric revenue for the six months ended June 30, 2015 and 2014, respectively.

^(b)  Includes a net of tax charge related to the Monticello LCM/EPU project.  See Note 5.