{"cik":67716,"taxonomy":"us-gaap","tag":"LongTermDebt","label":"Long-term Debt","description":"Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.","entityName":"MDU RESOURCES GROUP INC","units":{"USD":[{"end":"2015-12-31","val":1796163000,"accn":"0000067716-17-000017","fy":2016,"fp":"FY","form":"10-K","filed":"2017-02-24","frame":"CY2015Q4I"},{"end":"2016-12-31","val":1790159000,"accn":"0000067716-17-000017","fy":2016,"fp":"FY","form":"10-K","filed":"2017-02-24"},{"end":"2016-12-31","val":1790159000,"accn":"0000067716-18-000013","fy":2017,"fp":"FY","form":"10-K","filed":"2018-02-23","frame":"CY2016Q4I"},{"end":"2017-12-31","val":1714853000,"accn":"0000067716-18-000013","fy":2017,"fp":"FY","form":"10-K","filed":"2018-02-23"},{"end":"2017-12-31","val":1714853000,"accn":"0000067716-19-000019","fy":2018,"fp":"FY","form":"10-K","filed":"2019-02-22","frame":"CY2017Q4I"},{"end":"2018-12-31","val":2108695000,"accn":"0000067716-19-000019","fy":2018,"fp":"FY","form":"10-K","filed":"2019-02-22"},{"end":"2018-12-31","val":2108695000,"accn":"0000067716-19-000041","fy":2019,"fp":"Q1","form":"10-Q","filed":"2019-05-03"},{"end":"2018-12-31","val":2108695000,"accn":"0000067716-19-000060","fy":2019,"fp":"Q2","form":"10-Q","filed":"2019-08-02"},{"end":"2018-12-31","val":2108695000,"accn":"0000067716-19-000076","fy":2019,"fp":"Q3","form":"10-Q","filed":"2019-11-01"},{"end":"2018-12-31","val":2108695000,"accn":"0000067716-20-000010","fy":2019,"fp":"FY","form":"10-K","filed":"2020-02-21","frame":"CY2018Q4I"},{"end":"2019-03-31","val":2198027000,"accn":"0000067716-19-000041","fy":2019,"fp":"Q1","form":"10-Q","filed":"2019-05-03"},{"end":"2019-03-31","val":2198027000,"accn":"0000067716-20-000027","fy":2020,"fp":"Q1","form":"10-Q","filed":"2020-05-08","frame":"CY2019Q1I"},{"end":"2019-06-30","val":2379806000,"accn":"0000067716-19-000060","fy":2019,"fp":"Q2","form":"10-Q","filed":"2019-08-02"},{"end":"2019-06-30","val":2379806000,"accn":"0000067716-20-000044","fy":2020,"fp":"Q2","form":"10-Q","filed":"2020-08-06","frame":"CY2019Q2I"},{"end":"2019-09-30","val":2246756000,"accn":"0000067716-19-000076","fy":2019,"fp":"Q3","form":"10-Q","filed":"2019-11-01"},{"end":"2019-09-30","val":2246756000,"accn":"0000067716-20-000053","fy":2020,"fp":"Q3","form":"10-Q","filed":"2020-11-05","frame":"CY2019Q3I"},{"end":"2019-12-31","val":2243107000,"accn":"0000067716-20-000010","fy":2019,"fp":"FY","form":"10-K","filed":"2020-02-21"},{"end":"2019-12-31","val":2243107000,"accn":"0000067716-20-000027","fy":2020,"fp":"Q1","form":"10-Q","filed":"2020-05-08"},{"end":"2019-12-31","val":2243107000,"accn":"0000067716-20-000044","fy":2020,"fp":"Q2","form":"10-Q","filed":"2020-08-06"},{"end":"2019-12-31","val":2243107000,"accn":"0000067716-20-000053","fy":2020,"fp":"Q3","form":"10-Q","filed":"2020-11-05"},{"end":"2019-12-31","val":2243107000,"accn":"0000067716-21-000007","fy":2020,"fp":"FY","form":"10-K","filed":"2021-02-19","frame":"CY2019Q4I"},{"end":"2020-03-31","val":2455235000,"accn":"0000067716-20-000027","fy":2020,"fp":"Q1","form":"10-Q","filed":"2020-05-08"},{"end":"2020-03-31","val":2455235000,"accn":"0000067716-21-000026","fy":2021,"fp":"Q1","form":"10-Q","filed":"2021-05-06","frame":"CY2020Q1I"},{"end":"2020-06-30","val":2281876000,"accn":"0000067716-20-000044","fy":2020,"fp":"Q2","form":"10-Q","filed":"2020-08-06"},{"end":"2020-06-30","val":2281876000,"accn":"0000067716-21-000043","fy":2021,"fp":"Q2","form":"10-Q","filed":"2021-08-05","frame":"CY2020Q2I"},{"end":"2020-09-30","val":2270290000,"accn":"0000067716-20-000053","fy":2020,"fp":"Q3","form":"10-Q","filed":"2020-11-05"},{"end":"2020-09-30","val":2270290000,"accn":"0000067716-21-000055","fy":2021,"fp":"Q3","form":"10-Q","filed":"2021-11-04","frame":"CY2020Q3I"},{"end":"2020-12-31","val":2213130000,"accn":"0000067716-21-000007","fy":2020,"fp":"FY","form":"10-K","filed":"2021-02-19"},{"end":"2020-12-31","val":2213130000,"accn":"0000067716-21-000026","fy":2021,"fp":"Q1","form":"10-Q","filed":"2021-05-06"},{"end":"2020-12-31","val":2213130000,"accn":"0000067716-21-000043","fy":2021,"fp":"Q2","form":"10-Q","filed":"2021-08-05"},{"end":"2020-12-31","val":2213130000,"accn":"0000067716-21-000055","fy":2021,"fp":"Q3","form":"10-Q","filed":"2021-11-04"},{"end":"2020-12-31","val":2213130000,"accn":"0000067716-22-000012","fy":2021,"fp":"FY","form":"10-K","filed":"2022-02-23","frame":"CY2020Q4I"},{"end":"2021-03-31","val":2253274000,"accn":"0000067716-21-000026","fy":2021,"fp":"Q1","form":"10-Q","filed":"2021-05-06"},{"end":"2021-03-31","val":2253274000,"accn":"0000067716-22-000029","fy":2022,"fp":"Q1","form":"10-Q","filed":"2022-05-05","frame":"CY2021Q1I"},{"end":"2021-06-30","val":2337049000,"accn":"0000067716-21-000043","fy":2021,"fp":"Q2","form":"10-Q","filed":"2021-08-05"},{"end":"2021-06-30","val":2337049000,"accn":"0000067716-22-000052","fy":2022,"fp":"Q2","form":"10-Q","filed":"2022-08-05","frame":"CY2021Q2I"},{"end":"2021-09-30","val":2328266000,"accn":"0000067716-21-000055","fy":2021,"fp":"Q3","form":"10-Q","filed":"2021-11-04"},{"end":"2021-09-30","val":2328266000,"accn":"0000067716-22-000062","fy":2022,"fp":"Q3","form":"10-Q","filed":"2022-11-03","frame":"CY2021Q3I"},{"end":"2021-12-31","val":2741900000,"accn":"0000067716-22-000012","fy":2021,"fp":"FY","form":"10-K","filed":"2022-02-23"},{"end":"2021-12-31","val":2741900000,"accn":"0000067716-22-000029","fy":2022,"fp":"Q1","form":"10-Q","filed":"2022-05-05"},{"end":"2021-12-31","val":2741900000,"accn":"0000067716-22-000052","fy":2022,"fp":"Q2","form":"10-Q","filed":"2022-08-05"},{"end":"2021-12-31","val":2741900000,"accn":"0000067716-22-000062","fy":2022,"fp":"Q3","form":"10-Q","filed":"2022-11-03"},{"end":"2021-12-31","val":2741900000,"accn":"0000067716-23-000017","fy":2022,"fp":"FY","form":"10-K","filed":"2023-02-24","frame":"CY2021Q4I"},{"end":"2022-03-31","val":2747763000,"accn":"0000067716-22-000029","fy":2022,"fp":"Q1","form":"10-Q","filed":"2022-05-05"},{"end":"2022-03-31","val":2747763000,"accn":"0000067716-23-000066","fy":2023,"fp":"Q1","form":"10-Q","filed":"2023-05-04","frame":"CY2022Q1I"},{"end":"2022-06-30","val":2927967000,"accn":"0000067716-22-000052","fy":2022,"fp":"Q2","form":"10-Q","filed":"2022-08-05"},{"end":"2022-06-30","val":2090200000,"accn":"0000067716-23-000096","fy":2023,"fp":"Q2","form":"10-Q","filed":"2023-08-03","frame":"CY2022Q2I"},{"end":"2022-09-30","val":2988452000,"accn":"0000067716-22-000062","fy":2022,"fp":"Q3","form":"10-Q","filed":"2022-11-03"},{"end":"2022-09-30","val":2278730000,"accn":"0000067716-23-000112","fy":2023,"fp":"Q3","form":"10-Q","filed":"2023-11-02","frame":"CY2022Q3I"},{"end":"2022-12-31","val":2841425000,"accn":"0000067716-23-000017","fy":2022,"fp":"FY","form":"10-K","filed":"2023-02-24"},{"end":"2022-12-31","val":2841425000,"accn":"0000067716-23-000066","fy":2023,"fp":"Q1","form":"10-Q","filed":"2023-05-04"},{"end":"2022-12-31","val":2365667000,"accn":"0000067716-23-000096","fy":2023,"fp":"Q2","form":"10-Q","filed":"2023-08-03"},{"end":"2022-12-31","val":2365667000,"accn":"0000067716-23-000112","fy":2023,"fp":"Q3","form":"10-Q","filed":"2023-11-02"},{"end":"2022-12-31","val":2365667000,"accn":"0000067716-24-000017","fy":2023,"fp":"FY","form":"10-K","filed":"2024-02-22","frame":"CY2022Q4I"},{"end":"2023-03-31","val":2847068000,"accn":"0000067716-23-000066","fy":2023,"fp":"Q1","form":"10-Q","filed":"2023-05-04"},{"end":"2023-03-31","val":2239717000,"accn":"0000067716-24-000055","fy":2024,"fp":"Q1","form":"10-Q","filed":"2024-05-02","frame":"CY2023Q1I"},{"end":"2023-06-30","val":2247422000,"accn":"0000067716-23-000096","fy":2023,"fp":"Q2","form":"10-Q","filed":"2023-08-03"},{"end":"2023-06-30","val":2247422000,"accn":"0000067716-24-000082","fy":2024,"fp":"Q2","form":"10-Q","filed":"2024-08-08","frame":"CY2023Q2I"},{"end":"2023-09-30","val":2341147000,"accn":"0000067716-23-000112","fy":2023,"fp":"Q3","form":"10-Q","filed":"2023-11-02"},{"end":"2023-09-30","val":2341147000,"accn":"0000067716-24-000107","fy":2024,"fp":"Q3","form":"10-Q","filed":"2024-11-07","frame":"CY2023Q3I"},{"end":"2023-12-31","val":2298223000,"accn":"0000067716-24-000017","fy":2023,"fp":"FY","form":"10-K","filed":"2024-02-22"},{"end":"2023-12-31","val":2298223000,"accn":"0000067716-24-000055","fy":2024,"fp":"Q1","form":"10-Q","filed":"2024-05-02"},{"end":"2023-12-31","val":2298223000,"accn":"0000067716-24-000082","fy":2024,"fp":"Q2","form":"10-Q","filed":"2024-08-08"},{"end":"2023-12-31","val":2298223000,"accn":"0000067716-24-000107","fy":2024,"fp":"Q3","form":"10-Q","filed":"2024-11-07"},{"end":"2023-12-31","val":2166223000,"accn":"0000067716-25-000016","fy":2024,"fp":"FY","form":"10-K","filed":"2025-02-20","frame":"CY2023Q4I"},{"end":"2024-03-31","val":2386397000,"accn":"0000067716-24-000055","fy":2024,"fp":"Q1","form":"10-Q","filed":"2024-05-02"},{"end":"2024-03-31","val":2254397000,"accn":"0000067716-25-000042","fy":2025,"fp":"Q1","form":"10-Q","filed":"2025-05-08","frame":"CY2024Q1I"},{"end":"2024-06-30","val":2400617000,"accn":"0000067716-24-000082","fy":2024,"fp":"Q2","form":"10-Q","filed":"2024-08-08"},{"end":"2024-06-30","val":2268617000,"accn":"0000067716-25-000074","fy":2025,"fp":"Q2","form":"10-Q","filed":"2025-08-07","frame":"CY2024Q2I"},{"end":"2024-09-30","val":2452297000,"accn":"0000067716-24-000107","fy":2024,"fp":"Q3","form":"10-Q","filed":"2024-11-07"},{"end":"2024-09-30","val":2320297000,"accn":"0000067716-25-000090","fy":2025,"fp":"Q3","form":"10-Q","filed":"2025-11-10","frame":"CY2024Q3I"},{"end":"2024-12-31","val":2292610000,"accn":"0000067716-25-000016","fy":2024,"fp":"FY","form":"10-K","filed":"2025-02-20"},{"end":"2024-12-31","val":2292610000,"accn":"0000067716-25-000042","fy":2025,"fp":"Q1","form":"10-Q","filed":"2025-05-08"},{"end":"2024-12-31","val":2292610000,"accn":"0000067716-25-000074","fy":2025,"fp":"Q2","form":"10-Q","filed":"2025-08-07"},{"end":"2024-12-31","val":2292610000,"accn":"0000067716-25-000090","fy":2025,"fp":"Q3","form":"10-Q","filed":"2025-11-10"},{"end":"2024-12-31","val":2292610000,"accn":"0000067716-26-000014","fy":2025,"fp":"FY","form":"10-K","filed":"2026-02-20","frame":"CY2024Q4I"},{"end":"2025-03-31","val":2193676000,"accn":"0000067716-25-000042","fy":2025,"fp":"Q1","form":"10-Q","filed":"2025-05-08"},{"end":"2025-03-31","val":2193676000,"accn":"0000067716-26-000050","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-07","frame":"CY2025Q1I"},{"end":"2025-06-30","val":2181935000,"accn":"0000067716-25-000074","fy":2025,"fp":"Q2","form":"10-Q","filed":"2025-08-07"},{"end":"2025-06-30","val":2181935000,"accn":"0000067716-26-000072","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-06","frame":"CY2025Q2I"},{"end":"2025-09-30","val":2353185000,"accn":"0000067716-25-000090","fy":2025,"fp":"Q3","form":"10-Q","filed":"2025-11-10","frame":"CY2025Q3I"},{"end":"2025-12-31","val":2676855000,"accn":"0000067716-26-000014","fy":2025,"fp":"FY","form":"10-K","filed":"2026-02-20"},{"end":"2025-12-31","val":2676855000,"accn":"0000067716-26-000050","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-07"},{"end":"2025-12-31","val":2676855000,"accn":"0000067716-26-000072","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-06","frame":"CY2025Q4I"},{"end":"2026-03-31","val":2595996000,"accn":"0000067716-26-000050","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-07","frame":"CY2026Q1I"},{"end":"2026-06-30","val":2577157000,"accn":"0000067716-26-000072","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-06","frame":"CY2026Q2I"}]}}