Cover Page - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Jan. 31, 2026 |
Jun. 30, 2025 |
|
| Cover [Abstract] | |||
| Document Type | 10-K | ||
| Document Annual Report | true | ||
| Current Fiscal Year End Date | --12-31 | ||
| Document Period End Date | Dec. 31, 2025 | ||
| Document Transition Report | false | ||
| Entity File Number | 001-31303 | ||
| Entity Registrant Name | BLACK HILLS CORPORATION | ||
| Entity Incorporation, State or Country Code | SD | ||
| Entity Tax Identification Number | 46-0458824 | ||
| Entity Address, Address Line One | 7001 Mount Rushmore Road | ||
| Entity Address, City or Town | Rapid City | ||
| Entity Address, State or Province | SD | ||
| Entity Address, Postal Zip Code | 57702 | ||
| City Area Code | 605 | ||
| Local Phone Number | 721-1700 | ||
| Title of 12(b) Security | Common stock of $1.00 par value | ||
| Trading Symbol | BKH | ||
| Security Exchange Name | NYSE | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Entity Filer Category | Large Accelerated Filer | ||
| Entity Small Business | false | ||
| Entity Emerging Growth Company | false | ||
| ICFR Auditor Attestation Flag | true | ||
| Document Financial Statement Error Correction [Flag] | false | ||
| Entity Shell Company | false | ||
| Entity Public Float | $ 4,057,141,834 | ||
| Entity Common Stock, Shares Outstanding | 75,474,846 | ||
| Documents Incorporated by Reference | Portions of the registrant’s Definitive Proxy Statement being prepared for the solicitation of proxies in connection with the 2026 Annual Meeting of Stockholders to be held on April 29, 2026, are incorporated by reference in Part III of this Form 10-K | ||
| Entity Central Index Key | 0001130464 | ||
| Amendment Flag | false | ||
| Document Fiscal Year Focus | 2025 | ||
| Document Fiscal Period Focus | FY | ||
| Auditor Opinion [Text Block] | Opinion on the Financial Statements
We have audited the accompanying consolidated balance sheets of Black Hills Corporation and subsidiaries (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of income, comprehensive income, shareholders' equity, and cash flows, for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.
We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 11, 2026, expressed an unqualified opinion on the Company's internal control over financial reporting. |