Segment Information (Tables)

6 Months Ended

Jun. 30, 2019

Segment Reporting Information [Line Items]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

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

Three Months Ended
June 30, 2019	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	219,659		$	51,060		$	—		$	—	$	270,719
Cost of sales	42,661			13,083			—			—		55,744
Gross margin	176,998			37,977			—			—		214,975
Operating, general and administrative	59,328			20,965			533			—		80,826
Property and other taxes	34,834			9,474			2			—		44,310
Depreciation and depletion	33,720			7,296			—			—		41,016
Operating income (loss)	49,116			242			(535		)	—		48,823
Interest expense	(19,285		)	(1,501		)	(2,725		)	—		(23,511		)
Other (expense) income	(220		)	(53		)	397			—		124
Income tax (expense) benefit	(1,713		)	(354		)	24,293			—		22,226
Net income (loss)	$	27,898		$	(1,666	)	$	21,430		$	—	$	47,662
Total assets	$	4,568,469		$	1,147,330		$	4,636		$	—	$	5,720,435
Capital expenditures	$	63,785		$	17,665		$	—		$	—	$	81,450

Three Months Ended
June 30, 2018	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	209,755		$	52,062		$	—		$	—	$	261,817
Cost of sales	19,613			12,577			—			—		32,190
Gross margin	190,142			39,485			—			—		229,627
Operating, general and administrative	52,894			19,650			1,290			—		73,834
Property and other taxes	33,880			9,160			2			—		43,042
Depreciation and depletion	36,139			7,394			8			—		43,541
Operating income (loss)	67,229			3,281			(1,300		)	—		69,210
Interest expense	(20,318		)	(1,161		)	(1,718		)	—		(23,197		)
Other (expense) income	(52		)	(191		)	1,119			—		876
Income tax (expense) benefit	(2,649		)	492			(945		)	—		(3,102		)
Net income (loss)	$	44,210		$	2,421		$	(2,844	)	$	—	$	43,787
Total assets	$	4,351,359		$	1,072,173		$	15,442		$	—	$	5,438,974
Capital expenditures	$	52,844		$	11,607		$	—		$	—	$	64,451

Six Months Ended
June 30, 2019	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	492,696		$	162,243		$	—		$	—	$	654,939
Cost of sales	119,655			51,824			—			—		171,479
Gross margin	373,041			110,419			—			—		483,460
Operating, general and administrative	117,111			41,973			2,834			—		161,918
Property and other taxes	69,881			19,214			4			—		89,099
Depreciation and depletion	71,771			14,829			—			—		86,600
Operating income (loss)	114,278			34,403			(2,838		)	—		145,843
Interest expense	(38,820		)	(3,011		)	(5,470		)	—		(47,301		)
Other (expense) income	(781		)	(530		)	2,584			—		1,273
Income tax (expense) benefit	(3,522		)	725			23,450			—		20,653
Net income	$	71,155		$	31,587		$	17,726		$	—	$	120,468
Total assets	4,568,469			1,147,330			4,636			—		5,720,435
Capital expenditures	116,092			30,935			—			—		147,027

Six Months Ended
June 30, 2018	Electric			Gas			Other			Eliminations		Total
Operating revenues	$	448,097		$	155,222		$	—		$	—	$	603,319
Cost of sales	76,886			51,381			—			—		128,267
Gross margin	371,211			103,841			—			—		475,052
Operating, general and administrative	107,542			40,869			(232		)	—		148,179
Property and other taxes	67,373			18,478			4			—		85,855
Depreciation and depletion	72,292			14,988			16			—		87,296
Operating income	124,004			29,506			212			—		153,722
Interest expense	(39,838		)	(3,015		)	(3,314		)	—		(46,167		)
Other income (expense)	438			(83		)	(608		)	—		(253		)
Income tax expense	(3,147		)	(1,734		)	(135		)	—		(5,016		)
Net income (loss)	$	81,457		$	24,674		$	(3,845	)	$	—	$	102,286
Total assets	$	4,351,359		$	1,072,173		$	15,442		$	—	5,438,974
Capital expenditures	$	95,742		$	20,714		$	—		$	—	116,456