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v3.20.2

Cover page | Aug. 04, 2020
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Entity Information [Line Items] |
Document Type | 8-K
Document Period End Date | Aug. 04, 2020
Entity Registrant Name | MDU Resources Group Inc
Entity Incorporation, State or Country Code | DE
Entity File Number | 1-03480
Entity Tax Identification Number | 30-1133956
Entity Address, Address Line One | 1200 West Century Avenue
Entity Address, Address Line Two | P.O. Box 5650
Entity Address, City or Town | Bismarck
Entity Address, State or Province | ND
Entity Address, Postal Zip Code | 58506-5650
City Area Code | 701
Local Phone Number | 530-1000
Written Communications | false
Soliciting Material | false
Pre-commencement Tender Offer | false
Pre-commencement Issuer Tender Offer | false
Title of 12(b) Security | Common Stock, par value $1.00 per share
Trading Symbol | MDU
Security Exchange Name | NYSE
Entity Emerging Growth Company | false
Entity Central Index Key | 0000067716
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