Business segment data

9 Months Ended

Sep. 30, 2011

Business segment data [Abstract]

Business segment data

15. 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 vast majority of the Company's operations are located within the United States. The Company also has investments in foreign countries, which largely consist of Centennial Resources' equity method 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 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 pipeline and energy services segment provides natural gas transportation, underground storage and gathering services through regulated and nonregulated pipeline systems primarily in the Rocky Mountain and northern Great Plains regions of the United States. This segment also provides cathodic protection and other energy-related services.

The natural gas and oil production segment is engaged in natural gas and oil acquisition, exploration, development and production activities in the Rocky Mountain and Mid-Continent regions of the United States and in and around the Gulf of Mexico.

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 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 and automobile liability coverages. Centennial Capital also owns certain real and personal property. The Other category also includes Centennial Resources' equity method 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 2010 Annual Report. Information on the Company's businesses was as follows:

Three Months Ended September 30, 2011	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	61,949	$	—		$	8,312
Natural gas distribution		92,440		—			(11,183	)
Pipeline and energy services		58,459		10,591			5,221
		212,848		10,591			2,350
Construction services		222,822		3,344			5,044
Natural gas and oil production		96,803		23,956			22,497
Construction materials and contracting		619,134		—			33,103
Other		574		2,025			809
		939,333		29,325			61,453
Intersegment eliminations		—		(39,916	)		—
Total	$	1,152,181	$	—		$	63,803

Three Months Ended September 30, 2010	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	59,966	$	—		$	11,259
Natural gas distribution		94,336		—			(10,054	)
Pipeline and energy services		69,300		11,940			(7,370	)
		223,602		11,940			(6,165	)
Construction services		210,362		137			5,990
Natural gas and oil production		79,276		27,739			18,717
Construction materials and contracting		612,654		—			40,257
Other		29		2,263			2,039
		902,321		30,139			67,003
Intersegment eliminations		—		(42,079	)		—
Total	$	1,125,923	$	—		$	60,838

Nine Months Ended September 30, 2011	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	169,780	$	—		$	21,642
Natural gas distribution		627,450		—			18,235
Pipeline and energy services		167,636		47,836			16,913
		964,866		47,836			56,790
Construction services		617,699		9,940			15,815
Natural gas and oil production		262,604		74,889			60,093
Construction materials and contracting		1,138,280		—			16,680
Other		1,294		6,614			2,127
		2,019,877		91,443			94,715
Intersegment eliminations		—		(139,279	)		—
Total	$	2,984,743	$	—		$	151,505

Nine Months Ended September 30, 2010	External Operating Revenues		Inter- segment Operating Revenues			Earnings on Common Stock
	(In thousands)
Electric	$	155,345	$	—		$	22,091
Natural gas distribution		603,499		—			13,362
Pipeline and energy services		197,181		53,168			10,963
		956,025		53,168			46,416
Construction services		551,608		170			9,041
Natural gas and oil production		235,342		90,066			64,963
Construction materials and contracting		1,124,086		—			25,779
Other		83		6,714			5,007
		1,911,119		96,950			104,790
Intersegment eliminations		—		(150,118	)		—
Total	$	2,867,144	$	—		$	151,206

The Other category recognized a loss of $126,000 and income of $154,000, from discontinued operations, net of tax, for the three and nine months ended September 30, 2011, respectively. Excluding the natural gas gathering arbitration charge of $16.5 million (after tax) in 2010, as discussed in Note 18, earnings from electric, natural gas distribution and pipeline and energy services are substantially all from regulated operations. Earnings from construction services, natural gas and oil production, construction materials and contracting, and other are all from nonregulated operations.