XML 50 R39.htm IDEA: XBRL DOCUMENT
v3.22.2

Commitments, Contingencies and Guarantees: Agreement under Blockchain Interruptible Service Tariff (Details) - Blockchain Customer - Wyoming Electric - Maximum | Jun. 21, 2022 MW
--- | ---
Unrecorded Unconditional Purchase Obligation [Line Items] |
Electric Supply Commitment, Term | 5 years
Number of Megawatts Sold Under Long-Term Contract | 45
Option to Deliver an Increased Number of Megawatts Under a Long-Term Contract | 75

X
- Definition Electric Supply Commitment, Term + References No definition available. + Details
Name: | bkh_ElectricSupplyCommitmentTerm
Namespace Prefix: | bkh_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Megawatts Sold Under Long-Term Contract + References No definition available. + Details
Name: | bkh_NumberofMegawattsSoldUnderLongTermContract
Namespace Prefix: | bkh_
Data Type: | dtr-types:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Option to Deliver an Increased Number of Megawatts Under a Long-Term Contract + References No definition available. + Details
Name: | bkh_OptionToDeliverAnIncreasedNumberOfMegawattsUnderALongTermContract
Namespace Prefix: | bkh_
Data Type: | dtr-types:powerItemType
Balance Type: | na
Period Type: | instant

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 No definition available. + Details
Name: | us-gaap_UnrecordedUnconditionalPurchaseObligationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SupplyCommitmentAxis=bkh_BlockchainCustomerMember
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: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |