Asset Retirement Obligations (Tables)

6 Months Ended

Jun. 30, 2019

Asset Retirement Obligation [Abstract]

Schedule of Asset Retirement Obligations

The following table presents the AROs recorded on the Condensed Consolidated Balance Sheets.

	June 30, 2019
			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)	$	5,807	$	2,401	$	3,265	$	2,739	$	526	$	—	$	—	$	—
Closure of ash impoundments	6,498		2,894		2,858		2,839		19		47		699		—
Other	323		47		70		38		32		42		20		19
Total ARO	$	12,628	$	5,342	$	6,193	$	5,616	$	577	$	89	$	719	$	19
Less: current portion	739		203		416		413		3		6		115		—
Total noncurrent ARO	$	11,889	$	5,139	$	5,777	$	5,203	$	574	$	83	$	604	$	19

(a)    Duke Energy amount includes purchase accounting adjustments related to the merger with Progress Energy.

Schedule of Change in Asset Retirement Obligation

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, 2018(a)	$	10,467		$	3,949		$	5,411		$	4,820		$	591		$	93		$	722		$	19
Accretion expense(b)	245			111			124			111			13			2			14			—
Liabilities settled(c)	(404		)	(155		)	(225		)	(197		)	(28		)	(6		)	(17		)	—
Revisions in estimates of cash flows(d)	2,320			1,437			883			882			1			—			—			—
Balance at June 30, 2019	$	12,628		$	5,342		$	6,193		$	5,616		$	577		$	89		$	719		$	19

(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 six months ended June 30, 2019, 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.

(d)

Relates to increases in closure estimates for certain ash impoundments as a result of the NCDEQ's April 1 Order. See Note 4 for more information. The incremental amount recorded represents the discounted cash flows for estimated closure costs based upon the probability weightings of the potential closure methods as evaluated on a site-by-site basis.

Public Utilities General Disclosures

(in millions)	June 30, 2019		December 31, 2018
Duke Energy	$	6,327	$	5,579
Duke Energy Carolinas	3,574		3,133
Duke Energy Progress	2,753		2,446