XML 85 R75.htm IDEA: XBRL DOCUMENT v3.24.3

Contingencies - Guarantees (Details)	Sep. 30, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Guarantor obligations, maximum exposure, undiscounted	$ 557,500,000
Fixed maximum amounts guaranteed by year 2024	13,300,000
Fixed maximum amounts guaranteed by year 2025	186,700,000
Fixed maximum amounts guaranteed by year 2026	312,600,000
Fixed maximum amounts guaranteed by year 2027	43,500,000
Fixed maximum amounts guaranteed by year 2028	1,000,000
Fixed maximum amounts guaranteed, thereafter	400,000
Amount outstanding under guarantees that is reflected on balance sheet	0
Letters of credit	14,300,000
Letters of credit set to expire - 2024	12,300,000
Letters of credit set to expire - 2025	2,000,000
Outstanding letters of credit	0
Amount of surety bonds outstanding	$ 848,200,000

X

- Definition

Amount of surety bonds outstanding related to construction contracts and reclamation obligations.

+ References

No definition available.

+ Details

Name:	mdu_AmountOfSuretyBondsOutstanding
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Fixed maximum amounts guaranteed by year five.

+ References

No definition available.

+ Details

Name:	mdu_FixedMaximumAmountsGuaranteedByYearFive
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Fixed maximum amounts guaranteed by year four.

+ References

No definition available.

+ Details

Name:	mdu_FixedMaximumAmountsGuaranteedByYearFour
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Fixed maximum amounts guaranteed by year one.

+ References

No definition available.

+ Details

Name:	mdu_FixedMaximumAmountsGuaranteedByYearOne
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Fixed maximum amounts guaranteed by year three.

+ References

No definition available.

+ Details

Name:	mdu_FixedMaximumAmountsGuaranteedByYearThree
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Fixed maximum amounts guaranteed by year two.

+ References

No definition available.

+ Details

Name:	mdu_FixedMaximumAmountsGuaranteedByYearTwo
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Fixed maximum amounts guaranteed, thereafter.

+ References

No definition available.

+ Details

Name:	mdu_FixedMaximumAmountsGuaranteedThereafter
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Letters of credit.

+ References

No definition available.

+ Details

Name:	mdu_LettersOfCredit
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Letters of credit set to expire current year.

+ References

No definition available.

+ Details

Name:	mdu_LettersOfCreditSetToExpireCurrentYear
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Letters of credit set to expire in next fiscal year.

+ References

No definition available.

+ Details

Name:	mdu_LettersOfCreditSetToExpireInNextFiscalYear
Namespace Prefix:	mdu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

+ Details

Name:	us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant