v3.25.4
Employee Benefit Plans: Non-pension Defined Benefit Retiree Healthcare Plan (Details)
12 Months Ended
Dec. 31, 2025
Retirement Benefits [Abstract]
Percentage of healthcare plan assets invested
100.00%
X
- Definition
Percentage of healthcare plan assets invested.
+ References
No definition available.
+ Details
Name:
bkh_PercentageOfHealthcarePlanAssetsInvested
Namespace Prefix:
bkh_
Data Type:
dtr-types:percentItemType
Balance Type:
na
Period Type:
duration
X
- References
No definition available.
+ Details
Name:
us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:
us-gaap_
Data Type:
xbrli:stringItemType
Balance Type:
na
Period Type:
duration