XML 102 R92.htm IDEA: XBRL DOCUMENT
v3.23.2

WUTC (Details 4) - Pipeline Cost Recovery Mechanism - WUTC [Member] - Cascade Natural Gas [Member] - Pending Rate Case [Member] $ in Millions | Jun. 01, 2023 USD ($)
--- | ---
Public Utilities, General Disclosures [Line Items] |
Public Utilities, Requested Rate Increase (Decrease), Amount | $ 3.1
Public Utilities, Requested Rate Increase (Decrease), Percentage | 0.90%

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_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreasePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PublicUtilityAxis=mdu_PipelineCostRecoveryMechanismMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=mdu_WUTCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=mdu_CascadeNaturalGasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=mdu_PendingRateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |