    <SEC-DOCUMENT>0000067716-18-000048-index.html : 20180731
    <SEC-HEADER>0000067716-18-000048.hdr.sgml : 20180731
    <ACCEPTANCE-DATETIME>20180731172013
    ACCESSION NUMBER:		0000067716-18-000048
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		3
    CONFORMED PERIOD OF REPORT:	20180731
    ITEM INFORMATION:		Results of Operations and Financial Condition
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20180731
    DATE AS OF CHANGE:		20180731

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			MDU RESOURCES GROUP INC
    		CENTRAL INDEX KEY:			0000067716
    		STANDARD INDUSTRIAL CLASSIFICATION:	MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
    		IRS NUMBER:				410423660
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-03480
    		FILM NUMBER:		18982085

    	BUSINESS ADDRESS:
    		STREET 1:		1200 WEST CENTURY AVENUE
    		CITY:			BISMARCK
    		STATE:			ND
    		ZIP:			58503
    		BUSINESS PHONE:		701-530-1059

    	MAIL ADDRESS:
    		STREET 1:		1200 WEST CENTURY AVENUE
    		CITY:			BISMARCK
    		STATE:			ND
    		ZIP:			58503

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MONTANA DAKOTA UTILITIES CO
    		DATE OF NAME CHANGE:	19850429
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>a2018q2form8-k.htm
    <DESCRIPTION>MDU RESOURCES FORM 8-K
    <TEXT>
    Document 1 - file: a2018q2form8-k.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99
    <SEQUENCE>2
    <FILENAME>a2018q2ex99.htm
    <DESCRIPTION>MDU RESOURCES EX 99
    <TEXT>
    Document 2 - file: a2018q2ex99.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>mdurirpressreleasebasa02.jpg
    <DESCRIPTION>MDU RESOURCES LOGO
    <TEXT>
    Document 3 - file: mdurirpressreleasebasa02.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>