{"filing":{"accession_number":"0001193125-26-354167","cik":"0001130464","ticker":"BKH","company_name":"BLACK HILLS CORP /SD/","form":"8-K","filing_date":"2026-08-17","report_date":"2026-08-17","primary_document":"bkh-20260817.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/1130464/000119312526354167/bkh-20260817.htm"},"events":[{"id":28305,"run_id":25879,"accession_number":"0001193125-26-354167","anchor_item_number":"8.01","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.95,"summary":"Black Hills Corporation is disclosing the pending merger with NorthWestern Energy Group, Inc., an all-stock business combination entered into on August 18, 2025. The filing provides historical financial statements of NorthWestern and pro forma combined financial information as required by Regulation S-X. Multiple regulatory approvals have been obtained (FERC, NPSC, SDPUC), with the transaction awaiting final Montana PSC approval. This is a material acquisition/merger activity that would substantially affect the combined entity's financial position and operations.","company_name":"BLACK HILLS CORP /SD/","ticker":"BKH","filing_date":"2026-08-17","form":"8-K","submitted_at":null,"items":[{"id":30209,"accession_number":"0001193125-26-354167","item_number":"8.01","item_title":"Other Events.","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.95,"reasoning":"Black Hills Corporation is disclosing the pending merger with NorthWestern Energy Group, Inc., an all-stock business combination entered into on August 18, 2025. The filing provides historical financial statements of NorthWestern and pro forma combined financial information as required by Regulation S-X. Multiple regulatory approvals have been obtained (FERC, NPSC, SDPUC), with the transaction awaiting final Montana PSC approval. This is a material acquisition/merger activity that would substantially affect the combined entity's financial position and operations.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-08-17T20:35:33.301169+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":30209,"accession_number":"0001193125-26-354167","item_number":"8.01","item_title":"Other Events.","event_type":"ma_activity","event_domain":"operational","is_material":true,"confidence":0.95,"reasoning":"Black Hills Corporation is disclosing the pending merger with NorthWestern Energy Group, Inc., an all-stock business combination entered into on August 18, 2025. The filing provides historical financial statements of NorthWestern and pro forma combined financial information as required by Regulation S-X. Multiple regulatory approvals have been obtained (FERC, NPSC, SDPUC), with the transaction awaiting final Montana PSC approval. This is a material acquisition/merger activity that would substantially affect the combined entity's financial position and operations.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-08-17T20:35:33.301169+00:00","company_name":"BLACK HILLS CORP /SD/","ticker":"BKH","filing_date":"2026-08-17"}]}