{"schema_version":"secwatch.filing_event.v1","accession":"0001140361-23-024278","form_type":"8-K","ticker":"MDU","cik":"0000067716","company_name":"MDU RESOURCES GROUP INC","filed_at":"2023-05-12T23:59:59+00:00","discovered_at":"2026-05-14T18:03:41.946284+00:00","generated_at":"2026-06-15T03:03:41.411432+00:00","sec_items":["7.01","9.01"],"event_type":"other_material","sentiment":"neutral","materiality_score":0.85,"calibrated_materiality_score":0.85,"confidence":"high","headline":"MDU Resources spin-off of Knife River corp; distribution ratio 1:4; effective May 31","bullets":["Registration statement for Knife River spin-off declared effective by SEC.","Distribution of ~90% of Knife River shares to MDU holders: 1 share KNF per 4 shares MDU.","Record date May 22, distribution date May 31, 2023.","KNF to trade on NYSE after spin-off; when-issued trading starts May 25 under 'KNF WI'.","Investor day for Knife River scheduled for May 18, 2023."],"urls":{"canonical":"https://secwatch.observer/filing/0001140361-23-024278","json":"https://secwatch.observer/filing/0001140361-23-024278.json","markdown":"https://secwatch.observer/filing/0001140361-23-024278.md","text":"https://secwatch.observer/filing/0001140361-23-024278.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/67716/000114036123024278/0001140361-23-024278-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/67716/000114036123024278/ny20008720x1_8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-15T03:03:41.411432+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}