Business Segment Data - Schedule of Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting [Abstract]
Number Of Reportable Segments Not Disclosed Flag	reportable segments
Segment Reporting Information [Line Items]
Operating revenues	$ 605,977	$ 674,833
Purchased natural gas sold	239,391	317,157
Electric fuel and purchased power	46,067	43,748
Operation and maintenance	114,905	111,047
Depreciation and amortization	54,179	51,261
Taxes, other than income	35,730	38,757
Other income	2,605	4,997
Interest expense	32,685	26,822
Income tax (benefit) expense	4,678	8,571
Income from continuing operations	80,947	82,467
Discontinued operations, net of tax	(130)	(502)
Net income	80,817	81,965
Total reportable segment operating revenues
Segment Reporting Information [Line Items]
Operating revenues	640,693	708,441
Total reportable segment operating revenues \| Electric
Segment Reporting Information [Line Items]
Operating revenues	121,018	112,261
Purchased natural gas sold	0	0
Electric fuel and purchased power	46,067	43,748
Operation and maintenance	28,705	28,407
Depreciation and amortization	19,627	17,183
Taxes, other than income	5,520	4,815
Other income	451	992
Interest expense	11,911	7,887
Income tax (benefit) expense	(4,912)	(3,731)
Income from continuing operations	14,551	14,944
Discontinued operations, net of tax	0	0
Net income	14,551	14,944
Total reportable segment operating revenues \| Natural gas distribution
Segment Reporting Information [Line Items]
Operating revenues	462,347	539,248
Purchased natural gas sold	239,391	317,157
Electric fuel and purchased power	0	0
Operation and maintenance	65,126	63,484
Depreciation and amortization	26,333	26,122
Taxes, other than income	26,452	30,628
Other income	2,270	3,301
Interest expense	16,286	14,876
Income tax (benefit) expense	12,426	12,301
Income from continuing operations	44,183	44,658
Discontinued operations, net of tax	0	0
Net income	44,183	44,658
Total reportable segment operating revenues \| Pipeline
Segment Reporting Information [Line Items]
Operating revenues	22,612	23,323
Purchased natural gas sold	0	0
Electric fuel and purchased power	0	0
Operation and maintenance	20,769	19,239
Depreciation and amortization	8,219	7,956
Taxes, other than income	3,758	3,314
Other income	(423)	307
Interest expense	3,102	3,121
Income tax (benefit) expense	4,702	5,127
Income from continuing operations	15,254	17,210
Discontinued operations, net of tax	0	0
Net income	15,254	17,210
Total reportable segment operating revenues \| Other
Segment Reporting Information [Line Items]
Operating revenues	0	1
Purchased natural gas sold	0	0
Electric fuel and purchased power	0	0
Operation and maintenance	305	(83)
Depreciation and amortization	0	0
Taxes, other than income	0	0
Other income	307	397
Interest expense	1,386	938
Income tax (benefit) expense	(7,538)	(5,126)
Income from continuing operations	6,959	5,655
Discontinued operations, net of tax	(130)	(502)
Net income	6,829	5,153
Intersegment eliminations
Segment Reporting Information [Line Items]
Operating revenues	(34,915)	(33,787)
Purchased natural gas sold	(34,420)	(33,323)
Operation and maintenance	(495)	(464)
Other income	(920)	(1,109)
Interest expense	(920)	(1,109)
Intersegment eliminations \| Electric
Segment Reporting Information [Line Items]
Operating revenues	(167)	(178)
Purchased natural gas sold	0	0
Operation and maintenance	(167)	(178)
Other income	0	0
Interest expense	0	0
Intersegment eliminations \| Natural gas distribution
Segment Reporting Information [Line Items]
Operating revenues	(89)	(94)
Purchased natural gas sold	(34,420)	(33,323)
Operation and maintenance	(89)	(94)
Other income	0	0
Interest expense	0	0
Intersegment eliminations \| Pipeline
Segment Reporting Information [Line Items]
Operating revenues	(34,460)	(33,337)
Purchased natural gas sold	0	0
Operation and maintenance	(40)	(14)
Other income	(115)	(123)
Interest expense	(920)	(1,109)
Intersegment eliminations \| Other
Segment Reporting Information [Line Items]
Operating revenues	(199)	(178)
Purchased natural gas sold	0	0
Operation and maintenance	(199)	(178)
Other income	(805)	(986)
Interest expense	$ 0	$ 0

MDU RESOURCES GROUP INC 10-Q