Segment and Related Information

12 Months Ended

Dec. 31, 2014

Segment Reporting [Abstract]

Segment and Related Information

   Segment and Related Information

Our reportable business segments are primarily engaged in the electric and natural gas business. The remainder of our operations are presented as other, which primarily consists of unallocated corporate costs.

We evaluate the performance of these segments based on gross margin. The accounting policies of the operating segments are the same as the parent except that the parent allocates some of its operating expenses to the operating segments according to a methodology designed by management for internal reporting purposes and involves estimates and assumptions.

Financial data for the business segments are as follows (in thousands):

December 31, 2014	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	877,967		326,896			$	—		$	—	$	1,204,863
Cost of sales	348,640			133,951			—			—		482,591
Gross margin	529,327			192,945			—			—		722,272
Operating, general and administrative	200,186			91,437			14,263			—		305,886
Property and other taxes	84,759			29,821			12			—		114,592
Depreciation	94,813			28,930			33			—		123,776
Operating income (loss)	149,569			42,757			(14,308		)	—		178,018
Interest expense	(60,424		)	(10,618		)	(6,760		)	—		(77,802		)
Other income	4,758			1,324			4,116			—		10,198
Income tax (expense) benefit	(1,490		)	(7,463		)	19,225			—		10,272
Net income	$	92,413		$	26,000		$	2,273		$	—	$	120,686
Total assets	$	3,442,659		$	1,522,902		$	8,382		$	—	$	4,973,943
Capital expenditures	$	233,538		$	36,846		$	—		$	—	$	270,384

December 31, 2013	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	865,239		$	287,605		$	1,675		$	—	$	1,154,519
Cost of sales	358,688			120,858			—			—		479,546
Gross margin	506,551			166,747			1,675			—		674,973
Operating, general and administrative	195,100			78,822			11,647			—		285,569
Property and other taxes	78,536			26,993			11			—		105,540
Depreciation	89,728			23,070			33			—		112,831
Operating income (loss)	143,187			37,862			(10,016		)	—		171,033
Interest expense	(57,920		)	(9,993		)	(2,573		)	—		(70,486		)
Other income	4,061			1,239			2,437			—		7,737
Income tax (expense) benefit	(13,905		)	(4,134		)	3,738			—		(14,301		)
Net income (loss)	$	75,423		$	24,974		$	(6,414	)	$	—	$	93,983
Total assets	$	2,583,554		$	1,117,861		$	13,845		—		$	3,715,260
Capital expenditures	$	198,032		$	32,422		$	—		—		$	230,454

December 31, 2012	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	805,554		$	263,394		$	1,394		$	—	$	1,070,342
Cost of sales	277,826			117,608			—			—		395,434
Gross margin	527,728			145,786			1,394			—		674,908
Operating, general and administrative	187,599			75,971			6,396			—		269,966
MSTI impairment	24,039			—			—			—		24,039
Property and other taxes	72,755			24,907			12			—		97,674
Depreciation	86,559			19,452			33			—		106,044
Operating income (loss)	156,776			25,456			(5,047		)	—		177,185
Interest expense	(55,118		)	(9,063		)	(881		)	—		(65,062		)
Other income	2,630			1,633			109			—		4,372
Income tax (expense) benefit	(22,298		)	(692		)	4,901			—		(18,089		)
Net income	$	81,990		$	17,334		$	(918	)	$	—	$	98,406
Total assets	2,442,602			$	1,032,259		$	10,672		$	—	$	3,485,533
Capital expenditures	178,325			$	40,909		$	—		$	—	$	219,234