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Electric utility segment - Annual decoupling filings summary (Details) - USD ($) $ in Millions | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2019 | Dec. 31, 2018
Regulatory Projects and Legal Obligations [Line Items] |  |
2019 Annual incremental RAM adjusted revenues | $ 13.0 |
Annual change in accrued RBA balance as of December 31, 2018 (and associated revenue taxes) which incorporates MPIR recovery | (13.4) |
Performance Incentive Mechanisms (net) | (1.7) |
Net annual incremental amount to be collected (refunded) under the tariffs | (2.1) |
Hawaiian Electric (parent only) |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
2019 Annual incremental RAM adjusted revenues | 6.5 |
Annual change in accrued RBA balance as of December 31, 2018 (and associated revenue taxes) which incorporates MPIR recovery | (12.2) |
Performance Incentive Mechanisms (net) | (1.3) |
Net annual incremental amount to be collected (refunded) under the tariffs | (7.0) |
HELCO |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
2019 Annual incremental RAM adjusted revenues | 1.1 |
Annual change in accrued RBA balance as of December 31, 2018 (and associated revenue taxes) which incorporates MPIR recovery | (2.0) |
Performance Incentive Mechanisms (net) | 0.0 |
Net annual incremental amount to be collected (refunded) under the tariffs | (0.9) |
Maui Electric |  |
Regulatory Projects and Legal Obligations [Line Items] |  |
2019 Annual incremental RAM adjusted revenues | 5.4 |
Annual change in accrued RBA balance as of December 31, 2018 (and associated revenue taxes) which incorporates MPIR recovery | 0.8 |
Performance Incentive Mechanisms (net) | (0.4) |
Net annual incremental amount to be collected (refunded) under the tariffs | $ 5.8 |
2017 Tax Act Adjustment |  | $ (2.8)

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