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Electric utility segment - Power purchase agreements (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2019 | Mar. 31, 2018
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | $ 134 | $ 140
Hawaiian Electric (parent only) | Kalaeloa Partners, L.P. (Kalaeloa) |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 40 | 40
Hawaiian Electric (parent only) | AES Hawaii |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 32 | 37
Hawaiian Electric (parent only) | HPOWER |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 18 | 15
Hawaiian Electric (parent only) | Puna Geothermal Venture |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 0 | 11
Hawaiian Electric (parent only) | Hamakua Energy Partners, L.P. (HEP) |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 16 | 7
Hawaiian Electric (parent only) | Wind IPPs |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 20 | 22
Hawaiian Electric (parent only) | Solar IPPs |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | 7 | 6
Hawaiian Electric (parent only) | Other IPPs |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
Purchased power | $ 1 | $ 2

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- Definition Amount of operating expense for purchased power of regulated operation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2(b)) -URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227 + Details
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