XML 49 R37.htm IDEA: XBRL DOCUMENT
v3.23.2

Revenue: Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Revenue from contracts with customers | $ 405,136 | $ 470,324 | $ 1,317,191 | $ 1,292,093
Revenue | 411,283 | 474,195 | 1,332,442 | 1,297,765
Retail - Electric , Natural Gas and Coal |  |  |  |
Revenue from contracts with customers | 331,153 | 398,106 | 1,141,601 | 1,131,925
Transportation |  |  |  |
Revenue from contracts with customers | 35,798 | 34,567 | 88,526 | 83,991
Wholesale |  |  |  |
Revenue from contracts with customers | 5,739 | 8,428 | 15,137 | 18,703
Market - off-system sales |  |  |  |
Revenue from contracts with customers | 8,407 | 8,844 | 24,812 | 16,236
Transmission/Other |  |  |  |
Revenue from contracts with customers | 24,039 | 20,379 | 47,115 | 41,238
Other revenues |  |  |  |
Revenue | 6,147 | 3,871 | 15,251 | 5,672
Services transferred at a point in time |  |  |  |
Revenue from contracts with customers | 7,844 | 6,671 | 16,501 | 13,784
Services transferred over time |  |  |  |
Revenue from contracts with customers | 397,292 | 463,653 | 1,300,690 | 1,278,309
Electric Utilities |  |  |  |
Revenue from contracts with customers | 189,706 | 201,309 | 407,535 | 406,977
Revenue | 193,073 | 204,379 | 411,782 | 410,917
Electric Utilities | Retail - Electric , Natural Gas and Coal |  |  |  |
Revenue from contracts with customers | 156,372 | 169,032 | 331,275 | 341,838
Electric Utilities | Transportation |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Electric Utilities | Wholesale |  |  |  |
Revenue from contracts with customers | 5,739 | 8,428 | 15,137 | 18,703
Electric Utilities | Market - off-system sales |  |  |  |
Revenue from contracts with customers | 8,364 | 8,666 | 24,488 | 15,820
Electric Utilities | Transmission/Other |  |  |  |
Revenue from contracts with customers | 19,231 | 15,183 | 36,635 | 30,616
Electric Utilities | Other revenues |  |  |  |
Revenue | 3,367 | 3,070 | 4,247 | 3,940
Electric Utilities | Services transferred at a point in time |  |  |  |
Revenue from contracts with customers | 7,844 | 6,671 | 16,501 | 13,784
Electric Utilities | Services transferred over time |  |  |  |
Revenue from contracts with customers | 181,862 | 194,638 | 391,034 | 393,193
Gas Utilities |  |  |  |
Revenue from contracts with customers | 219,940 | 273,263 | 918,632 | 893,612
Revenue | 222,720 | 274,169 | 929,636 | 895,561
Gas Utilities | Retail - Electric , Natural Gas and Coal |  |  |  |
Revenue from contracts with customers | 174,781 | 229,074 | 810,326 | 790,087
Gas Utilities | Transportation |  |  |  |
Revenue from contracts with customers | 35,913 | 34,667 | 88,756 | 84,190
Gas Utilities | Wholesale |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Gas Utilities | Market - off-system sales |  |  |  |
Revenue from contracts with customers | 43 | 178 | 324 | 416
Gas Utilities | Transmission/Other |  |  |  |
Revenue from contracts with customers | 9,203 | 9,344 | 19,226 | 18,919
Gas Utilities | Other revenues |  |  |  |
Revenue | 2,780 | 906 | 11,004 | 1,949
Gas Utilities | Services transferred at a point in time |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Gas Utilities | Services transferred over time |  |  |  |
Revenue from contracts with customers | 219,940 | 273,263 | 918,632 | 893,612
Inter-segment Revenues |  |  |  |
Revenue from contracts with customers | (4,510) | (4,248) | (8,976) | (8,496)
Revenue | (4,510) | (4,353) | (8,976) | (8,713)
Inter-segment Revenues | Retail - Electric , Natural Gas and Coal |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-segment Revenues | Transportation |  |  |  |
Revenue from contracts with customers | (115) | (100) | (230) | (199)
Inter-segment Revenues | Wholesale |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-segment Revenues | Market - off-system sales |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-segment Revenues | Transmission/Other |  |  |  |
Revenue from contracts with customers | (4,395) | (4,148) | (8,746) | (8,297)
Inter-segment Revenues | Other revenues |  |  |  |
Revenue | 0 | (105) | 0 | (217)
Inter-segment Revenues | Services transferred at a point in time |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-segment Revenues | Services transferred over time |  |  |  |
Revenue from contracts with customers | $ (4,510) | $ (4,248) | $ (8,976) | $ (8,496)

X
- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9031-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9038-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130543-203045 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130545-203045 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 924 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -URI https://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856 + Details
Name: | us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9031-108599 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9038-108599 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -URI https://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 22: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_MajorCustomersAxis=bkh_RetailElectricNaturalGasandCoalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=bkh_TransportationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=bkh_WholesaleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=bkh_MarketOffSystemSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=bkh_TransmissionOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=bkh_OtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredAtPointInTimeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredOverTimeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=bkh_ElectricUtilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=bkh_GasUtilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |