XML 168 R137.htm IDEA: XBRL DOCUMENT
v3.20.4

Information by Business Segments - Schedule of Business Segments (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Segment Reporting Information [Line Items] |  |  |
Operating revenues | $ 1,321,891 | $ 1,345,622 | $ 1,396,893
Resource costs | 398,509 | 439,817 | 494,736
Other operating expenses | 359,958 | 383,770 | 350,073
Depreciation and amortization | 224,223 | 205,994 | 183,676
Income (loss) from operations | 232,700 | 210,389 | 261,113
Interest expense | 105,061 | 104,354 | 100,936
Income taxes | 7,051 | 31,374 | 26,060
Net income (loss) from continuing operations attributable to Avista Corp. shareholders | 129,488 | 196,979 | 136,429
Capital expenditures | 405,674 | 443,345 | 425,241
Total Assets | 6,402,097 | 6,082,456 | 5,782,576
Avista Utilities [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 1,277,468 | 1,295,873 | 1,325,966
Alaska Electric Light & Power [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 42,809 | 37,265 | 43,599
Operating Segments [Member] | Utility Revenue [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 1,320,277 | 1,333,138 | 1,369,565
Resource costs | 398,509 | 439,817 | 494,736
Other operating expenses | 354,614 | 364,887 | 321,992
Depreciation and amortization | 223,507 | 205,365 | 182,877
Income (loss) from operations | 237,146 | 217,417 | 262,665
Interest expense | 104,723 | 104,251 | 100,322
Income taxes | 7,932 | 31,179 | 28,353
Net income (loss) from continuing operations attributable to Avista Corp. shareholders | 132,905 | 191,435 | 143,166
Capital expenditures | 404,306 | 442,510 | 424,350
Total Assets | 6,304,311 | 5,984,661 | 5,731,054
Operating Segments [Member] | Avista Utilities [Member] | Utility Revenue [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 1,277,468 | 1,295,873 | 1,325,966
Resource costs | 396,543 | 442,471 | 485,231
Other operating expenses | 341,709 | 352,170 | 309,501
Depreciation and amortization | 213,701 | 195,697 | 177,006
Income (loss) from operations | 220,058 | 200,994 | 248,000
Interest expense | 98,451 | 97,866 | 96,738
Income taxes | 4,921 | 28,363 | 25,259
Net income (loss) from continuing operations attributable to Avista Corp. shareholders | 124,810 | 183,977 | 134,874
Capital expenditures | 397,292 | 434,077 | 418,741
Total Assets | 6,035,340 | 5,713,268 | 5,458,104
Operating Segments [Member] | Alaska Electric Light & Power [Member] | Utility Revenue [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 42,809 | 37,265 | 43,599
Resource costs | 1,966 | (2,654) | 9,505
Other operating expenses | 12,905 | 12,717 | 12,491
Depreciation and amortization | 9,806 | 9,668 | 5,871
Income (loss) from operations | 17,088 | 16,423 | 14,665
Interest expense | 6,272 | 6,385 | 3,584
Income taxes | 3,011 | 2,816 | 3,094
Net income (loss) from continuing operations attributable to Avista Corp. shareholders | 8,095 | 7,458 | 8,292
Capital expenditures | 7,014 | 8,433 | 5,609
Total Assets | 268,971 | 271,393 | 272,950
Other [Member] | Non-Utility Revenue [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 1,614 | 12,484 | 27,328
Resource costs | 0 | 0 | 0
Other operating expenses | 5,344 | 18,883 | 28,081
Depreciation and amortization | 716 | 629 | 799
Income (loss) from operations | (4,446) | (7,028) | (1,552)
Interest expense | 524 | 1,032 | 1,694
Income taxes | (881) | 195 | (2,293)
Net income (loss) from continuing operations attributable to Avista Corp. shareholders | (3,417) | 5,544 | (6,737)
Capital expenditures | 1,368 | 835 | 891
Total Assets | 109,658 | 113,390 | 87,050
Intersegment Eliminations [Member] |  |  |
Segment Reporting Information [Line Items] |  |  |
Operating revenues | 0 | 0 | 0
Resource costs | 0 | 0 | 0
Other operating expenses | 0 | 0 | 0
Depreciation and amortization | 0 | 0 | 0
Income (loss) from operations | 0 | 0 | 0
Interest expense | (186) | (929) | (1,080)
Income taxes | 0 | 0 | 0
Net income (loss) from continuing operations attributable to Avista Corp. shareholders | 0 | 0 | 0
Capital expenditures | 0 | 0 | 0
Total Assets | $ (11,872) | $ (15,595) | $ (35,528)

X
- Definition Depreciation And Amortization Expense + References No definition available. + Details
Name: | ava_DepreciationAndAmortizationExpense
Namespace Prefix: | ava_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest Expense Including Affiliated Trusts + References No definition available. + Details
Name: | ava_InterestExpenseIncludingAffiliatedTrusts
Namespace Prefix: | ava_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other Operating Expenses + References No definition available. + Details
Name: | ava_OtherOperatingExpenses
Namespace Prefix: | ava_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Payments to acquire property plant and equipment excludes other business expenditure. + References No definition available. + Details
Name: | ava_PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure
Namespace Prefix: | ava_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Utilities operating expense (deferrals) for products and services. + References No definition available. + Details
Name: | ava_UtilitiesOperatingExpenseDeferralsForProductsAndServices
Namespace Prefix: | ava_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(11)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: 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 http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 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 http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=121559654&loc=d3e5710-111685 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(12)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 + Details
Name: | us-gaap_Assets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after tax of income (loss) from continuing operations attributable to the parent. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4613673-111683 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 60B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 11 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.13) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 11 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794 + Details
Name: | us-gaap_IncomeLossFromContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I.7) -URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32672-109319 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 4: 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(h)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120385591&loc=d3e38679-109324 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(9)) -URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The net result for the period of deducting operating expenses from operating revenues. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=120311839&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 22 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 + Details
Name: | us-gaap_OperatingIncomeLoss
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 http://asc.fasb.org/extlink&oid=120311839&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 http://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 http://asc.fasb.org/extlink&oid=75031198&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 http://asc.fasb.org/extlink&oid=120311839&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 http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599 Reference 11: 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 http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 12: 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 http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 13: 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 http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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

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

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

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

X
- Details
Name: | srt_ProductOrServiceAxis=ava_NonUtilityRevenueMember
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: |