XML 67 R57.htm IDEA: XBRL DOCUMENT
v3.22.1

Disaggregation of revenue (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2022 | Mar. 31, 2021
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | $ 1,416,559 | $ 1,227,938
Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (31,730) | (30,935)
Intrasegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (46,033) | (46,716)
Natural gas transportation |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 43,955 | 41,869
Natural gas storage |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 3,719 | 4,029
Contracting services |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 114,267 | 96,025
Construction materials |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 241,732 | 216,412
Electrical & mechanical specialty contracting |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 392,808 | 355,190
Transmission & distribution specialty contracting |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 148,466 | 151,363
Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 21,460 | 18,819
Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 1,409,053 | 1,216,016
Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 7,506 | 11,922
Residential utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 296,120 | 236,573
Commercial utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 199,209 | 152,980
Industrial utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 23,330 | 18,841
Other utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 1,750 | 1,566
Electric |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 93,594 | 84,673
Electric | Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (124) | (136)
Electric | Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 12,753 | 9,773
Electric | Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 97,589 | 87,596
Electric | Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (3,995) | (2,923)
Electric | Residential utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 37,304 | 33,436
Electric | Commercial utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 35,600 | 32,928
Electric | Industrial utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 10,306 | 10,029
Electric | Other utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 1,750 | 1,566
Natural gas distribution |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 450,418 | 350,206
Natural gas distribution | Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (136) | (142)
Natural gas distribution | Natural gas transportation |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 12,381 | 12,452
Natural gas distribution | Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 2,609 | 3,009
Natural gas distribution | Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 450,303 | 347,320
Natural gas distribution | Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 115 | 2,886
Natural gas distribution | Residential utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 258,816 | 203,137
Natural gas distribution | Commercial utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 163,609 | 120,052
Natural gas distribution | Industrial utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 13,024 | 8,812
Natural gas distribution | Other utility sales |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 0 | 0
Pipeline |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 11,120 | 9,913
Pipeline | Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (25,940) | (26,229)
Pipeline | Natural gas transportation |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 31,574 | 29,417
Pipeline | Natural gas storage |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 3,719 | 4,029
Pipeline | Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 1,709 | 2,660
Pipeline | Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 11,062 | 9,877
Pipeline | Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 58 | 36
Construction materials and contracting |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 309,836 | 265,659
Construction materials and contracting | Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (130) | (62)
Construction materials and contracting | Intrasegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (46,033) | (46,716)
Construction materials and contracting | Contracting services |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 114,267 | 96,025
Construction materials and contracting | Construction materials |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 241,732 | 216,412
Construction materials and contracting | Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 0 | 0
Construction materials and contracting | Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 309,836 | 265,659
Construction materials and contracting | Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 0 | 0
Construction services |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 551,591 | 517,470
Construction services | Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (1,059) | (1,042)
Construction services | Electrical & mechanical specialty contracting |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 392,808 | 355,190
Construction services | Transmission & distribution specialty contracting |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 148,466 | 151,363
Construction services | Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 48 | 36
Construction services | Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 540,263 | 505,547
Construction services | Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 11,328 | 11,923
Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 0 | 17
Other | Intersegment eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | (4,341) | (3,324)
Other | Other |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 4,341 | 3,341
Other | Revenues from contracts with customers |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | 0 | 17
Other | Revenues out of scope |  |
Disaggregation of Revenue [Line Items] |  |
Operating revenues: | $ 0 | $ 0

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -URI http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 22: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsegmentsConsolidationItemsAxis=us-gaap_IntersubsegmentEliminationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_NaturalGasTransportationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_NaturalGasStorageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_ContractingServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_ConstructionMaterialsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_InsideSpecialtyContractingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_OutsideSpecialtyContractingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_OtherRevenuesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_RevenueFromContractsWithCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mdu_RevenuesOutOfScopeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=mdu_ResidentialUtilitySalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=mdu_CommercialUtilitySalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=mdu_IndustrialUtilitySalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=mdu_OtherUtilitySalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mdu_ElectricMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mdu_NaturalGasDistributionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mdu_PipelineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mdu_ConstructionMaterialsAndContractingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mdu_ConstructionServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |