v3.26.1

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2026
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arr Modified [Flag]	false
Non Rule 10b51 Arr Modified [Flag]	false

- Definition

Non rule 10b51 arr modified flag.

+ References

No definition available.

+ Details

Name:	bkh_NonRule10B51ArrModifiedFlag
Namespace Prefix:	bkh_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

Rule 10b5-1 arr modified flag.

+ References

No definition available.

+ Details

Name:	bkh_Rule10B51ArrModifiedFlag
Namespace Prefix:	bkh_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-K
-Number 229
-Section 408
-Subsection a
-Paragraph 1

+ Details

Name:	ecd_NonRule10b51ArrAdoptedFlag
Namespace Prefix:	ecd_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-K
-Number 229
-Section 408
-Subsection a
-Paragraph 1

+ Details

Name:	ecd_NonRule10b51ArrTrmntdFlag
Namespace Prefix:	ecd_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-K
-Number 229
-Section 408
-Subsection a
-Paragraph 1

+ Details

Name:	ecd_Rule10b51ArrAdoptedFlag
Namespace Prefix:	ecd_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-K
-Number 229
-Section 408
-Subsection a
-Paragraph 1

+ Details

Name:	ecd_Rule10b51ArrTrmntdFlag
Namespace Prefix:	ecd_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-K
-Number 229
-Section 408
-Subsection a
-Paragraph 2
-Subparagraph A

+ Details

Name:	ecd_TradingArrByIndTable
Namespace Prefix:	ecd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

BLACK HILLS CORP /SD/ 10-Q