Business segment data

3 Months Ended

Mar. 31, 2018

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 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 construction materials and contracting segment operations mine, process and sell construction aggregates (crushed stone, sand and gravel); produce and sell asphalt mix; and supply ready-mixed concrete. This segment focuses on vertical integration of its contracting services with its construction materials to support the aggregate based product lines including aggregate placement, asphalt and concrete paving, and site development and grading. Although not common to all locations, other products include the sale of cement, liquid asphalt for various commercial and roadway applications, various finished concrete products and other building materials and related contracting services. This segment operates in the central, southern and western United States and Alaska and Hawaii.

The construction services segment provides inside and outside specialty contracting services. Its outside services include design, construction and maintenance of overhead and underground electrical distribution and transmission lines, substations, external lighting, traffic signalization, and gas pipelines, as well as utility excavation and the manufacture and distribution of transmission line construction equipment. Its inside services include design, construction and maintenance of electrical and communication wiring and infrastructure, fire suppression systems, and mechanical piping and services. This segment also constructs and

maintains renewable energy projects. These specialty contracting services are provided to utilities and large manufacturing, commercial, industrial, institutional and government customers.

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 self-insured layers of the insured Company's general liability, automobile liability, pollution liability and other 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 Brazil.

Discontinued operations includes the results and supporting activities of Dakota Prairie Refining and Fidelity other than certain general and administrative costs and interest expense as described above. For more information on discontinued operations, see Note 9.

The information below follows the same accounting policies as described in Note 1 of the Company's Notes to Consolidated Financial Statements in the 2017 Annual Report. Information on the Company's segments was as follows:



	Three Months Ended
	March 31,
	2018			2017
	(In thousands)
External operating revenues:
Regulated operations:
Electric	$	87,404		$	88,225
Natural gas distribution	332,664			342,519
Pipeline and midstream	4,391			2,870
	424,459			433,614
Nonregulated operations:
Pipeline and midstream	4,442			3,643
Construction materials and contracting	213,284			200,776
Construction services	334,050			299,572
Other	58			320
	551,834			504,311
Total external operating revenues	$	976,293		$	937,925

Intersegment operating revenues:
Regulated operations:
Electric	$	—		$	—
Natural gas distribution	—			—
Pipeline and midstream	21,735			21,489
	21,735			21,489
Nonregulated operations:
Pipeline and midstream	24			34
Construction materials and contracting	101			86
Construction services	11			6
Other	2,638			1,743
	2,774			1,869
Intersegment eliminations	(24,509		)	(23,358		)
Total intersegment operating revenues	$	—		$	—



	Three Months Ended
	March 31,
	2018			2017
	(In thousands)
Earnings on common stock:
Regulated operations:
Electric	$	13,084		$	14,333
Natural gas distribution	32,623			27,861
Pipeline and midstream	5,459			4,557
	51,166			46,751
Nonregulated operations:
Pipeline and midstream	(179		)	(628		)
Construction materials and contracting	(23,521		)	(19,912		)
Construction services	15,090			7,362
Other	(596		)	(279		)
	(9,206		)	(13,457		)
Intersegment eliminations*	—			2,173
Earnings on common stock before income from discontinued operations	41,960			35,467
Income from discontinued operations, net of tax*	477			1,687
Total earnings on common stock	$	42,437		$	37,154


*	Includes an elimination for the presentation of income tax adjustments between continuing and discontinued operations.