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Asset Retirement Obligations | 9 Months Ended
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Sep. 30, 2018
Asset Retirement Obligation [Abstract] |
Asset Retirement Obligations | ASSET RETIREMENT OBLIGATIONS The Duke Energy Registrants record AROs when there is a legal obligation to incur retirement costs associated with the retirement of a long-lived asset and the obligation can be reasonably estimated. The following table presents the AROs recorded on the Condensed Consolidated Balance Sheets.
| September 30, 2018
|  |  | Duke |  |  |  |  | Duke |  |  | Duke |  |  | Duke |  |  | Duke |  |  |
| Duke |  |  | Energy |  |  | Progress |  |  | Energy |  |  | Energy |  |  | Energy |  |  | Energy |  |  |
(in millions) | Energy |  |  | Carolinas |  |  | Energy |  |  | Progress |  |  | Florida |  |  | Ohio |  |  | Indiana |  |  | Piedmont |
Decommissioning of Nuclear Power Facilities(a) | $ | 5,367 |  |  | $ | 2,031 |  |  | $ | 3,181 |  |  | $ | 2,650 |  |  | $ | 531 |  |  | $ | — |  |  | $ | — |  |  | $ | — |
Closure of Ash Impoundments | 4,575 |  |  | 1,623 |  |  | 2,175 |  |  | 2,154 |  |  | 20 |  |  | 52 |  |  | 725 |  |  | — |
Other | 314 |  |  | 58 |  |  | 79 |  |  | 37 |  |  | 42 |  |  | 46 |  |  | 19 |  |  | 15 |
Total ARO | $ | 10,256 |  |  | $ | 3,712 |  |  | $ | 5,435 |  |  | $ | 4,841 |  |  | $ | 593 |  |  | $ | 98 |  |  | $ | 744 |  |  | $ | 15 |
Less: current portion | 902 |  |  | 292 |  |  | 475 |  |  | 470 |  |  | 4 |  |  | 7 |  |  | 128 |  |  | — |
Total noncurrent ARO | $ | 9,354 |  |  | $ | 3,420 |  |  | $ | 4,960 |  |  | $ | 4,371 |  |  | $ | 589 |  |  | $ | 91 |  |  | $ | 616 |  |  | $ | 15 |
(a) Duke Energy amount includes purchase accounting adjustments related to the merger with Progress Energy. ARO Liability Rollforward Actual closure costs incurred could be materially different from current estimates that form the basis of the recorded AROs. The following table presents the change in liability associated with AROs for the Duke Energy Registrants.
|  |  | Duke |  |  |  |  | Duke |  |  | Duke |  |  | Duke |  |  | Duke |  |  |
| Duke |  |  | Energy |  |  | Progress |  |  | Energy |  |  | Energy |  |  | Energy |  |  | Energy |  |  |
(in millions) | Energy |  |  | Carolinas |  |  | Energy |  |  | Progress |  |  | Florida |  |  | Ohio |  |  | Indiana |  |  | Piedmont |
Balance at December 31, 2017(a) | $ | 10,175 |  |  | $ | 3,610 |  |  | $ | 5,414 |  |  | $ | 4,673 |  |  | $ | 742 |  |  | $ | 84 |  |  | $ | 781 |  |  | $ | 15 |
Accretion expense(b) | 319 |  |  | 133 |  |  | 168 |  |  | 145 |  |  | 23 |  |  | 3 |  |  | 22 |  |  | — |
Liabilities settled(c) | (431 | ) |  | (198 | ) |  | (186 | ) |  | (155 | ) |  | (31 | ) |  | (5 | ) |  | (42 | ) |  | — |
Liabilities incurred in the current year | 34 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 25 |  |  | — |
Revisions in estimates of cash flows(d) | 159 |  |  | 159 |  |  | 39 |  |  | 178 |  |  | (141 | ) |  | 16 |  |  | (42 | ) |  | — |
Balance at September 30, 2018 | $ | 10,256 |  |  | $ | 3,712 |  |  | $ | 5,435 |  |  | $ | 4,841 |  |  | $ | 593 |  |  | $ | 98 |  |  | $ | 744 |  |  | $ | 15 |
(a) | Primarily relates to decommissioning nuclear power facilities, closure of ash impoundments, asbestos removal, closure of landfills at fossil generation facilities, retirement of natural gas mains and removal of renewable energy generation assets.
(b) | For the nine months ended September 30, 2018, substantially all accretion expense relates to Duke Energy's regulated operations and has been deferred in accordance with regulatory accounting treatment.
(c) | Primarily relates to ash impoundment closures and nuclear decommissioning of Crystal River Unit 3.
(d) | Primarily relates to increases in groundwater monitoring estimates for closure of ash impoundments, partially offset by modifications to the timing of expected cash flows and a reduction for nuclear decommissioning at Crystal River Unit 3 compared to original estimates.
Asset retirement costs associated with the AROs for operating plants and retired plants are included in Net property, plant and equipment and Regulatory assets within Other Noncurrent Assets, respectively, on the Condensed Consolidated Balance Sheets.

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- References No definition available. + Details
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- Definition The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -URI http://asc.fasb.org/subtopic&trid=2175671 + Details
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