Consolidated Statements of Changes in Total Equity (USD $) In Millions, unless otherwise specified	Total		PEC [Member]	PEF [Member]	Common Stock Equity [Member]	Common Stock Equity [Member] PEC [Member]	Common Stock Equity [Member] PEF [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] PEC [Member]	Retained Earnings [Member] PEF [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] PEC [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] PEF [Member]	Accumulated Defined Benefit Plans Adjustment [Member]	Common Stockholders' Equity [Member]	Noncontrolling Interests [Member]
Beginning balance at Dec. 31, 2010	$ 10,027		$ 5,180	$ 4,890	$ 7,332	$ 2,130	$ 1,750	$ 11	$ 2,805	$ 3,083	$ 3,144	$ (63)	$ (33)	$ (4)	$ (62)	$ 10,023	$ 4
Net income	653	[1]	437	418					651	437	418					651	2
Other comprehensive (loss) income	(82)		(37)	(22)								(77)	(37)	(22)	(5)	(82)
Issuance of shares	42				42											42
Stock-based compensation expense	28		14	5	24	14	5	4								28
Dividends paid to parent			(450)	(475)						(450)	(475)
Dividends declared	(550)								(550)							(550)
Preferred stock dividends at stated rates			(2)	(1)						(2)	(1)
Distributions to noncontrolling interests	(3)																(3)
Tax dividend				(2)							(2)
Notes To Reconciliation Of Total Equity [Details]
Net income	656		437	418
Net income attributable to preferred shareholders of subsidiaries excluded from reconciliation of total equity	3
Ending balance at Sep. 30, 2011	10,115		5,142	4,813	7,398	2,144	1,755	15	2,906	3,068	3,084	(140)	(70)	(26)	(67)	10,112	3
Beginning balance at Jun. 30, 2011
Notes To Reconciliation Of Total Equity [Details]
Net income	293		199	203
Ending balance at Sep. 30, 2011	10,115		5,142	4,813
Beginning balance at Dec. 31, 2011	10,025		5,088	4,675	7,418	2,148	1,757	16	2,752	3,011	2,945	(143)	(71)	(27)	(22)	10,021	4
Net income	370	[1]	180	311					368	180	311					368	2
Other comprehensive (loss) income	99		71	26								99	71	26		99
Issuance of shares	6				6											6
Stock-based compensation expense	25		11	5	12	11	5	13								25
Dividends paid to parent			(310)	(170)						(310)	(170)
Dividends declared	(369)								(369)							(369)
Preferred stock dividends at stated rates			(2)	(1)						(2)	(1)
Distributions to noncontrolling interests	(2)																(2)
Tax dividend				(1)							(1)
Issuance of 100 shares of $.01 par value common shares to Duke Energy					(7,436)			7,436
Other	(1)																(1)
Notes To Reconciliation Of Total Equity [Details]
Net income	373		180	311
Net income attributable to preferred shareholders of subsidiaries excluded from reconciliation of total equity	3
Ending balance at Sep. 30, 2012	10,153		5,038	4,845	0	2,159	1,762	7,465	2,751	2,879	3,084	(44)	0	(1)	(22)	10,150	3
Beginning balance at Jun. 30, 2012
Notes To Reconciliation Of Total Equity [Details]
Net income	157		96	100
Ending balance at Sep. 30, 2012	$ 10,153		$ 5,038	$ 4,845											$ (22)

[1] For the nine months ended September 30, 2012, consolidated net income of $373 million includes $3 million attributable to preferred shareholders of subsidiaries. For the nine months ended September 30, 2011, consolidated net income of $656 million includes $3 million attributable to preferred shareholders of subsidiaries. Income attributable to preferred shareholders of subsidiaries is not a component of total equity and is excluded from the table above.