Business segment data

6 Months Ended

Jun. 30, 2016

Segment Reporting [Abstract]

Business segment data

Business segment data

The Company's reportable segments are those that are based on the Company's method of internal reporting, which generally segregates the strategic business units due to differences in products, services and regulation. The internal reporting of these operating segments is defined based on the reporting and review process used by the Company's chief executive officer. The vast majority of the Company's operations are located within the United States.

The electric segment generates, transmits and distributes electricity in Montana, North Dakota, South Dakota and Wyoming. The natural gas distribution segment distributes natural gas in those states as well as in Idaho, Minnesota, Oregon and Washington. These operations also supply related value-added services.

The pipeline and midstream segment provides natural gas transportation, underground storage, gathering and processing services, as well as oil gathering, through regulated and nonregulated pipeline systems and processing facilities primarily in the Rocky Mountain and northern Great Plains regions of the United States.

The construction materials and contracting segment mines aggregates and markets crushed stone, sand, gravel and related construction materials, including ready-mixed concrete, cement, asphalt, liquid asphalt and other value-added products. It also performs integrated contracting services. This segment operates in the central, southern and western United States and Alaska and Hawaii.

The construction services segment provides utility construction services specializing in constructing and maintaining electric and communications lines, gas pipelines, fire suppression systems, and external lighting and traffic signalization. This segment also provides utility excavation and inside electrical and mechanical services, and manufactures and distributes transmission line construction equipment and other supplies.

The Other category includes the activities of Centennial Capital, which insures various types of risks as a captive insurer for certain of the Company's subsidiaries. The function of the captive insurer is to fund the deductible layers of the insured companies' general liability, automobile liability and pollution liability coverages. Centennial Capital also owns certain real and personal property. The Other category also includes certain general and administrative costs (reflected in operation and maintenance expense) and interest expense which were previously allocated to the refining business and Fidelity and do not meet the criteria for income (loss) from discontinued operations. The Other category also includes Centennial Resources' former investment in the Brazilian Transmission Lines.

Discontinued operations includes the results of Dakota Prairie Refining and Fidelity other than certain general and administrative costs and interest expense as described above. Dakota Prairie Refining refined crude oil and produced and sold diesel fuel, naphtha, ATBs and other by-products of the production process. In the second quarter of 2016, the Company sold all of the outstanding membership interests in Dakota Prairie Refining. Fidelity engaged in oil and natural gas development and production activities in the Rocky Mountain and Mid-Continent/Gulf States regions of the United States. Between September 2015 and March 2016, the Company entered into purchase and sale agreements to sell all of Fidelity's marketed oil and natural gas assets. The completion of these sales occurred between October 2015 and April 2016. For more information on discontinued operations, see Note 10.

The information below follows the same accounting policies as described in Note 1 of the Company's Notes to Consolidated Financial Statements in the 2015 Annual Report. Information on the Company's businesses was as follows:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2016		2015		2016		2015
	(In thousands)
External operating revenues:
Regulated operations:
Electric	$	73,832	$	64,265	$	156,755	$	136,041
Natural gas distribution	112,770		132,965		412,165		463,538
Pipeline and midstream	19,450		18,448		22,998		22,588
	206,052		215,678		591,918		622,167
Nonregulated operations:
Pipeline and midstream	10,268		14,749		18,966		27,749
Construction materials and contracting	541,257		495,640		751,108		701,298
Construction services	285,924		211,515		541,424		446,918
Other	447		457		747		752
	837,896		722,361		1,312,245		1,176,717
Total external operating revenues	$	1,043,948	$	938,039	$	1,904,163	$	1,798,884

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2016			2015			2016			2015
	(In thousands)
Intersegment operating revenues:
Regulated operations:
Electric	$	—		$	—		$	—		$	—
Natural gas distribution	—			—			—			—
Pipeline and midstream	6,594			6,564			27,691			27,625
	6,594			6,564			27,691			27,625
Nonregulated operations:
Pipeline and midstream	36			110			119			316
Construction materials and contracting	97			1,257			215			2,205
Construction services	77			3,491			539			15,186
Other	1,669			1,792			3,338			3,563
	1,879			6,650			4,211			21,270
Intersegment eliminations	(8,473		)	(13,214		)	(31,902		)	(48,895		)
Total intersegment operating revenues	$	—		$	—		$	—		$	—
Earnings (loss) on common stock:
Regulated operations:
Electric	$	8,022		$	5,910		$	19,141		$	14,237
Natural gas distribution	(7,777		)	(5,375		)	17,464			16,075
Pipeline and midstream	5,564			4,328			10,852			9,685
	5,809			4,863			47,457			39,997
Nonregulated operations:
Pipeline and midstream	737			(966		)	739			89
Construction materials and contracting	33,696			20,136			19,225			5,501
Construction services	6,990			7,003			12,964			11,763
Other	(1,105		)	(4,404		)	(2,564		)	(9,358		)
	40,318			21,769			30,364			7,995
Intersegment eliminations	—			(742		)	—			(1,733		)
Earnings on common stock before loss from discontinued operations	46,127			25,890			77,821			46,259
Loss from discontinued operations, net of tax	(276,102		)	(263,419		)	(294,138		)	(593,404		)
Loss from discontinued operations attributable to noncontrolling interest	(120,651		)	(7,754		)	(131,691		)	(11,282		)
Total loss on common stock	$	(109,324	)	$	(229,775	)	$	(84,626	)	$	(535,863	)