Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2019

Asset Retirement Obligation [Abstract]

Schedule of Asset Retirement Obligations

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

	September 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)	$	5,789	$	2,435	$	3,295	$	2,769	$	526	$	—	$	—	$	—
Closure of ash impoundments	6,486		2,917		2,722		2,707		15		43		804		—
Other	326		46		71		38		33		42		20		20
Total ARO	$	12,601	$	5,398	$	6,088	$	5,514	$	574	$	85	$	824	$	20
Less: current portion	861		214		478		476		2		3		165		—
Total noncurrent ARO	$	11,740	$	5,184	$	5,610	$	5,038	$	572	$	82	$	659	$	20

(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)	377			173			190			171			19			3			21			1
Liabilities settled(c)	(691		)	(276		)	(375		)	(341		)	(34		)	(9		)	(32		)	—
Revisions in estimates of cash flows(d)	2,448			1,552			862			864			(2		)	(2		)	113			—
Balance at September 30, 2019	$	12,601		$	5,398		$	6,088		$	5,514		$	574		$	85		$	824		$	20

(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, 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)

Primarily 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)	September 30, 2019		December 31, 2018
Duke Energy	$	6,403	$	5,579
Duke Energy Carolinas	3,614		3,133
Duke Energy Progress	2,789		2,446