Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000067716-23-000112-index-headers.html | 2023-11-02 16:43:40 | |
| 0000067716-23-000112-index.html | 2023-11-02 16:43:40 | |
| 0000067716-23-000112.txt | 2023-11-02 16:43:40 | |
 0000067716-23-000112-xbrl.zip | 366761 | 2023-11-02 16:43:40 |
| a2023q3ex31a.htm | 9214 | 2023-11-02 16:43:40 |
| a2023q3ex31b.htm | 8838 | 2023-11-02 16:43:40 |
| a2023q3ex32.htm | 5363 | 2023-11-02 16:43:40 |
| FilingSummary.xml | 54404 | 2023-11-02 16:43:40 |
| Financial_Report.xlsx | 160080 | 2023-11-02 16:43:40 |
| mdu-20230930.htm | 2848122 | 2023-11-02 16:43:40 |
| mdu-20230930.xsd | 66405 | 2023-11-02 16:43:40 |
| mdu-20230930_cal.xml | 86663 | 2023-11-02 16:43:40 |
| mdu-20230930_def.xml | 481472 | 2023-11-02 16:43:40 |
| mdu-20230930_htm.xml | 2648788 | 2023-11-02 16:43:40 |
| mdu-20230930_lab.xml | 939726 | 2023-11-02 16:43:40 |
| mdu-20230930_pre.xml | 645047 | 2023-11-02 16:43:40 |
| MetaLinks.json | 1111705 | 2023-11-02 16:43:40 |
| R1.htm | 53362 | 2023-11-02 16:43:40 |
| R10.htm | 5288 | 2023-11-02 16:43:40 |
| R11.htm | 78942 | 2023-11-02 16:43:40 |
| R12.htm | 15776 | 2023-11-02 16:43:40 |
| R13.htm | 36565 | 2023-11-02 16:43:40 |
| R14.htm | 100150 | 2023-11-02 16:43:40 |
| R15.htm | 179405 | 2023-11-02 16:43:40 |
| R16.htm | 5147 | 2023-11-02 16:43:40 |
| R17.htm | 25894 | 2023-11-02 16:43:40 |
| R18.htm | 80216 | 2023-11-02 16:43:40 |
| R19.htm | 102132 | 2023-11-02 16:43:40 |
| R2.htm | 109576 | 2023-11-02 16:43:40 |
| R20.htm | 47800 | 2023-11-02 16:43:40 |
| R21.htm | 8332 | 2023-11-02 16:43:40 |
| R22.htm | 18929 | 2023-11-02 16:43:40 |
| R23.htm | 107609 | 2023-11-02 16:43:40 |
| R24.htm | 44012 | 2023-11-02 16:43:40 |
| R25.htm | 6895 | 2023-11-02 16:43:40 |
| R26.htm | 12963 | 2023-11-02 16:43:40 |
| R27.htm | 15608 | 2023-11-02 16:43:40 |
| R28.htm | 15921 | 2023-11-02 16:43:40 |
| R29.htm | 10263 | 2023-11-02 16:43:40 |
| R3.htm | 61023 | 2023-11-02 16:43:40 |
| R30.htm | 5114 | 2023-11-02 16:43:40 |
| R31.htm | 10603 | 2023-11-02 16:43:40 |
| R32.htm | 5294 | 2023-11-02 16:43:40 |
| R33.htm | 12024 | 2023-11-02 16:43:40 |
| R34.htm | 6562 | 2023-11-02 16:43:40 |
| R35.htm | 5276 | 2023-11-02 16:43:40 |
| R36.htm | 6838 | 2023-11-02 16:43:40 |
| R37.htm | 6733 | 2023-11-02 16:43:40 |
| R38.htm | 8451 | 2023-11-02 16:43:40 |
| R39.htm | 6447 | 2023-11-02 16:43:40 |
| R4.htm | 167261 | 2023-11-02 16:43:40 |
| R40.htm | 7889 | 2023-11-02 16:43:40 |
| R41.htm | 9167 | 2023-11-02 16:43:40 |
| R42.htm | 62379 | 2023-11-02 16:43:40 |
| R43.htm | 75093 | 2023-11-02 16:43:40 |
| R44.htm | 15683 | 2023-11-02 16:43:40 |
| R45.htm | 34867 | 2023-11-02 16:43:40 |
| R46.htm | 128077 | 2023-11-02 16:43:40 |
| R47.htm | 170367 | 2023-11-02 16:43:40 |
| R48.htm | 27409 | 2023-11-02 16:43:40 |
| R49.htm | 148364 | 2023-11-02 16:43:40 |
| R5.htm | 100730 | 2023-11-02 16:43:40 |
| R50.htm | 101586 | 2023-11-02 16:43:40 |
| R51.htm | 39748 | 2023-11-02 16:43:40 |
| R52.htm | 17811 | 2023-11-02 16:43:40 |
| R53.htm | 102343 | 2023-11-02 16:43:40 |
| R54.htm | 38201 | 2023-11-02 16:43:40 |
| R55.htm | 42449 | 2023-11-02 16:43:40 |
| R56.htm | 81565 | 2023-11-02 16:43:40 |
| R57.htm | 23796 | 2023-11-02 16:43:40 |
| R58.htm | 4557 | 2023-11-02 16:43:40 |
| R59.htm | 37576 | 2023-11-02 16:43:40 |
| R6.htm | 114949 | 2023-11-02 16:43:40 |
| R60.htm | 15510 | 2023-11-02 16:43:40 |
| R61.htm | 4898 | 2023-11-02 16:43:40 |
| R62.htm | 42455 | 2023-11-02 16:43:40 |
| R63.htm | 52009 | 2023-11-02 16:43:40 |
| R64.htm | 43355 | 2023-11-02 16:43:40 |
| R65.htm | 94531 | 2023-11-02 16:43:40 |
| R66.htm | 26046 | 2023-11-02 16:43:40 |
| R67.htm | 14198 | 2023-11-02 16:43:40 |
| R68.htm | 7425 | 2023-11-02 16:43:40 |
| R69.htm | 6164 | 2023-11-02 16:43:40 |
| R7.htm | 9146 | 2023-11-02 16:43:40 |
| R70.htm | 19174 | 2023-11-02 16:43:40 |
| R71.htm | 14717 | 2023-11-02 16:43:40 |
| R72.htm | 52471 | 2023-11-02 16:43:40 |
| R73.htm | 49483 | 2023-11-02 16:43:40 |
| R74.htm | 3891 | 2023-11-02 16:43:40 |
| R75.htm | 7618 | 2023-11-02 16:43:40 |
| R76.htm | 18828 | 2023-11-02 16:43:40 |
| R77.htm | 12770 | 2023-11-02 16:43:40 |
| R78.htm | 44465 | 2023-11-02 16:43:40 |
| R79.htm | 12561 | 2023-11-02 16:43:40 |
| R8.htm | 20102 | 2023-11-02 16:43:40 |
| R80.htm | 39008 | 2023-11-02 16:43:40 |
| R81.htm | 55254 | 2023-11-02 16:43:40 |
| R82.htm | 18293 | 2023-11-02 16:43:40 |
| R83.htm | 16166 | 2023-11-02 16:43:40 |
| R84.htm | 14306 | 2023-11-02 16:43:40 |
| R85.htm | 8867 | 2023-11-02 16:43:40 |
| R86.htm | 106526 | 2023-11-02 16:43:40 |
| R87.htm | 19353 | 2023-11-02 16:43:40 |
| R88.htm | 38030 | 2023-11-02 16:43:40 |
| R89.htm | 14074 | 2023-11-02 16:43:40 |
| R9.htm | 63927 | 2023-11-02 16:43:40 |
| R90.htm | 18535 | 2023-11-02 16:43:40 |
| R91.htm | 23630 | 2023-11-02 16:43:40 |
| R92.htm | 12452 | 2023-11-02 16:43:40 |
| R93.htm | 14300 | 2023-11-02 16:43:40 |
| R94.htm | 8315 | 2023-11-02 16:43:40 |
| R95.htm | 10085 | 2023-11-02 16:43:40 |
| R96.htm | 25035 | 2023-11-02 16:43:40 |
| R97.htm | 7740 | 2023-11-02 16:43:40 |
| report.css | 2768 | 2023-11-02 16:43:40 |
| Show.js | 1086 | 2023-11-02 16:43:40 |