v3.26.1
Business segment data
 6 Months Ended
Jun. 30, 2026
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 CODM, the chief executive officer. The Company's operations are located within the United States.
The Company's CODM regularly reviews discrete financial information of each reportable segment and uses net income to assess the performance of each reportable segment. The CODM uses this information to assess performance and make decisions about resources to be allocated to each reportable segment, including capital and personnel. The information provided to the CODM is prepared at the reportable segment level in quarterly financial packages and on a more summarized basis monthly. Budget and forecast information is also provided to the CODM at the reportable segment level.
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 segment provides natural gas transportation and underground storage services through a FERC regulated pipeline system primarily in the Rocky Mountain and northern Great Plains regions of the United States. This segment also provides non-regulated energy-related services, including cathodic protection.
The Other category includes the activities of Centennial Capital, which, through its subsidiary InterSource Insurance Company, 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 and other coverages. In addition, the Other category includes certain assets, liabilities and tax adjustments of the holding company primarily associated with corporate functions. Also included are certain general and administrative costs (reflected in operation and maintenance expense) and interest expense, which were previously allocated to the Company's former businesses which do not meet the criteria for discontinued operations.
Discontinued operations includes certain costs associated with legacy business activities other than certain general and administrative costs and interest expense as described above.
The information below follows the same accounting policies as described in Note 2 of the Notes to Consolidated Financial Statements in the 2025 Annual Report. Information on the Company's segments was as follows:
Three Months Ended June 30, 2026ElectricNatural gas distributionPipelineOtherConsolidated
(In thousands)
Operating revenues:
External operating revenues$115,916 $212,647 $46,740 $— $375,303 
Intersegment operating revenues124 86 10,052 201 10,463 
Purchased natural gas sold:
External purchased natural gas sold— 93,538 — — 93,538 
Intersegment purchased natural gas sold— 9,900 — — 9,900 
Electric fuel and purchased power38,674 — — — 38,674 
Operation and maintenance:
External operation and maintenance31,015 60,741 22,247 13 114,016 
Intersegment operation and maintenance124 86 152 201 563 
Depreciation and amortization20,287 26,639 8,257 — 55,183 
Taxes, other than income5,368 16,806 3,773 — 25,947 
Other income:
External other income1,842 3,865 242 278 6,227 
Intersegment other income— — 76 326 402 
Interest expense:
External interest expense11,094 15,945 3,801 708 31,548 
Intersegment interest expense— — 402 — 402 
Income tax expense (benefit)(3,343)(3,215)4,042 5,867 3,351 
Income (loss) from continuing operations14,663 (3,842)14,436 (5,984)19,273 
Discontinued operations, net of tax— — — 1,967 1,967 
Net income (loss)
$14,663 $(3,842)$14,436 $(4,017)$21,240 
Three Months Ended June 30, 2025ElectricNatural gas distributionPipelineOtherConsolidated
(In thousands)
Operating revenues:
External operating revenues$97,886 $206,794 $46,507 $(1)$351,186 
Intersegment operating revenues140 92 9,796 180 10,208 
Purchased natural gas sold:
External purchased natural gas sold— 96,057 — — 96,057 
Intersegment purchased natural gas sold— 9,751 — — 9,751 
Electric fuel and purchased power34,891 — — — 34,891 
Operation and maintenance:
External operation and maintenance29,823 60,456 22,352 256 112,887 
Intersegment operation and maintenance140 92 45 180 457 
Depreciation and amortization17,393 26,471 7,989 — 51,853 
Taxes, other than income4,648 16,935 3,583 — 25,166 
Other income:
External other income2,726 5,095 1,616 508 9,945 
Intersegment other income— — 90 1,061 1,151 
Interest expense:
External interest expense7,614 13,745 3,135 951 25,445 
Intersegment interest expense— — 1,151 — 1,151 
Income tax expense (benefit)(4,254)(4,170)4,337 4,742 655 
Income (loss) from continuing operations
10,497 (7,356)15,417 (4,381)14,177 
Discontinued operations, net of tax— — — (397)(397)
Net income (loss)
$10,497 $(7,356)$15,417 $(4,778)$13,780 
Six Months Ended June 30, 2026ElectricNatural gas distributionPipelineOtherConsolidated
(In thousands)
Operating revenues:
External operating revenues$236,934 $674,994 $69,352 $— $981,280 
Intersegment operating revenues291 175 44,512 400 45,378 
Purchased natural gas sold:
External purchased natural gas sold— 332,929 — — 332,929 
Intersegment purchased natural gas sold— 44,320 — — 44,320 
Electric fuel and purchased power84,741 — — — 84,741 
Operation and maintenance:
External operation and maintenance59,720 125,867 43,016 318 228,921 
Intersegment operation and maintenance291 175 192 400 1,058 
Depreciation and amortization39,914 52,972 16,476 — 109,362 
Taxes, other than income10,888 43,258 7,531 — 61,677 
Other income:
External other income2,293 6,135 (181)585 8,832 
Intersegment other income— — 191 1,131 1,322 
Interest expense:
External interest expense23,005 32,231 6,903 2,094 64,233 
Intersegment interest expense— — 1,322 — 1,322 
Income tax (benefit) expense
(8,255)9,211 8,744 (1,671)8,029 
Income from continuing operations29,214 40,341 29,690 975 100,220 
Discontinued operations, net of tax— — — 1,837 1,837 
Net income$29,214 $40,341 $29,690 $2,812 $102,057 
Six Months Ended June 30, 2025ElectricNatural gas distributionPipelineOtherConsolidated
(In thousands)
Operating revenues:
External operating revenues$210,147 $746,041 $69,831 $— $1,026,019 
Intersegment operating revenues318 187 43,132 358 43,995 
Purchased natural gas sold:
External purchased natural gas sold— 413,214 — — 413,214 
Intersegment purchased natural gas sold— 43,074 — — 43,074 
Electric fuel and purchased power78,639 — — — 78,639 
Operation and maintenance:
External operation and maintenance58,230 123,939 41,592 173 223,934 
Intersegment operation and maintenance318 187 58 358 921 
Depreciation and amortization34,576 52,593 15,945 — 103,114 
Taxes, other than income9,463 47,563 6,897 — 63,923 
Other income:
External other income3,718 8,396 1,923 905 14,942 
Intersegment other income— — 213 2,047 2,260 
Interest expense:
External interest expense15,501 28,621 6,256 1,889 52,267 
Intersegment interest expense— — 2,260 — 2,260 
Income tax (benefit) expense
(7,985)8,131 9,464 (384)9,226 
Income from continuing operations25,441 37,302 32,627 1,274 96,644 
Discontinued operations, net of tax— — — (899)(899)
Net income$25,441 $37,302 $32,627 $375 $95,745 
A reconciliation of reportable segment operating revenues to consolidated operating revenues is as follows:
Three Months EndedSix Months Ended
June 30,June 30,
2026 2025 2026 2025 
(In thousands)
Operating revenues reconciliation:
Total reportable segment operating revenues$385,565 $361,215 $1,026,258 $1,069,656 
Other revenue201 179 400 358 
Elimination of intersegment operating revenues(10,463)(10,208)(45,378)(43,995)
Total consolidated operating revenues$375,303 $351,186 $981,280 $1,026,019