XML 49 R41.htm IDEA: XBRL DOCUMENT v3.24.1.u1

Financing: Debt Covenants (Additional Information) (Details)	Mar. 31, 2024
Line of Credit Facility [Line Items]
Consolidated indebtedness to capitalization ratio	0.57
Maximum
Line of Credit Facility [Line Items]
Consolidated indebtedness to capitalization ratio	0.65
Wyoming Electric
Line of Credit Facility [Line Items]
Consolidated indebtedness to capitalization ratio	0.52
Wyoming Electric | Maximum
Line of Credit Facility [Line Items]
Consolidated indebtedness to capitalization ratio	0.6

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

+ Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Indebtedness divided by net capital.

+ References

No definition available.

+ Details

Name:	us-gaap_RatioOfIndebtednessToNetCapital1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=bkh_WyomingElectricMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: