XML 111 R81.htm IDEA: XBRL DOCUMENT
v3.22.4

Goodwill impairment testing results (Details 4) - USD ($) $ in Thousands | Dec. 31, 2022 | Oct. 31, 2022 | Dec. 31, 2021 | Oct. 31, 2021 | Dec. 31, 2020
--- | --- | --- | --- | --- | ---
Goodwill [Line Items] |  |  |  |  |
Goodwill | $ 763,500 |  | $ 765,386 |  | $ 714,963
Natural gas distribution |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |
Goodwill | $ 345,736 |  | $ 345,736 |  | $ 345,736
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount |  | 8.00% |  |  |
Risk Adjusted Cost of Capital, Percent |  | 6.40% |  | 5.00% |

X
- Definition Risk Adjusted Cost of Capital, Percent + References No definition available. + Details
Name: | mdu_RiskAdjustedCostOfCapitalPercent
Namespace Prefix: | mdu_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(10)(1)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 55 -Paragraph 24 -URI https://asc.fasb.org/extlink&oid=122137925&loc=d3e14258-109268 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 55 -Paragraph 10 -URI https://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(15)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Percentage of fair value of reporting unit in excess of carrying amount. + References No definition available. + Details
Name: | us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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