Business segment data

6 Months Ended

Jun. 30, 2014

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 Company also has an investment in a foreign country, which consists of Centennial Resources' investment in ECTE.

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 energy services segment provides natural gas transportation, underground storage, processing and gathering 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. This segment is constructing the Dakota Prairie Refinery in conjunction with Calumet to refine crude oil and also provides cathodic protection and other energy-related services.

The exploration and production segment is engaged in oil and natural gas acquisition, exploration, development and production activities in the Rocky Mountain and Mid-Continent/Gulf States 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 specializes in constructing and maintaining electric and communication lines, gas pipelines, fire suppression systems, and external lighting and traffic signalization equipment. This segment also provides utility excavation services and inside electrical wiring, cabling and mechanical services, sells and distributes electrical materials, and manufactures and distributes specialty equipment.

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 Centennial Resources' investment in ECTE.

The information below follows the same accounting policies as described in Note 1 of the Company's Notes to Consolidated Financial Statements in the 2013 Annual Report. Information on the Company's businesses was as follows:

Three Months Ended June 30, 2014	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	65,149	$	—		$	7,823
Natural gas distribution	146,077		—			(4,494		)
Pipeline and energy services	43,463		7,888			5,789
	254,689		7,888			9,118
Exploration and production	129,309		10,271			19,180
Construction materials and contracting	434,452		8,106			10,554
Construction services	275,109		7,273			14,307
Other	487		1,744			1,608
	839,357		27,394			45,649
Intersegment eliminations	—		(35,282		)	(832		)
Total	$	1,094,046	$	—		$	53,935

Three Months Ended June 30, 2013	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	56,981	$	—		$	4,410
Natural gas distribution	127,584		—			(5,893		)
Pipeline and energy services	42,877		7,999			(6,395		)
	227,442		7,999			(7,878		)
Exploration and production	137,053		12,556			32,995
Construction materials and contracting	418,345		12,958			10,025
Construction services	277,259		2,340			12,915
Other	496		1,839			340
	833,153		29,693			56,275
Intersegment eliminations	—		(37,692		)	(2,056		)
Total	$	1,060,595	$	—		$	46,341

Six Months Ended June 30, 2014	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	138,796	$	—		$	18,856
Natural gas distribution	520,311		—			22,768
Pipeline and energy services	87,124		26,164			10,138
	746,231		26,164			51,762
Exploration and production	245,976		31,139			40,120
Construction materials and contracting	598,875		12,123			(13,019		)
Construction services	545,002		11,010			30,875
Other	815		3,468			1,872
	1,390,668		57,740			59,848
Intersegment eliminations	—		(83,904		)	(1,184		)
Total	$	2,136,899	$	—		$	110,426

Six Months Ended June 30, 2013	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	121,635	$	—		$	14,235
Natural gas distribution	459,337		—			26,624
Pipeline and energy services	70,593		26,717			(4,064		)
	651,565		26,717			36,795
Exploration and production	252,415		22,369			53,279
Construction materials and contracting	580,323		17,251			(10,557		)
Construction services	507,065		3,914			24,579
Other	830		3,657			645
	1,340,633		47,191			67,946
Intersegment eliminations	—		(73,908		)	(2,056		)
Total	$	1,992,198	$	—		$	102,685

Earnings from electric, natural gas distribution and pipeline and energy services are substantially all from regulated operations. Earnings from exploration and production, construction materials and contracting, construction services and other are all from nonregulated operations.