Employee Benefit Plans (Summary Of Amount Included In Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Prefunded pension cost	$ 163	[1]
Accrued pension liability	(439)		(139)
Net amount recognized	(276)		(139)
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Prefunded pension cost	123	[1]
Accrued pension liability			(11)
Net amount recognized	123		(11)
Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(221)		(538)
Net amount recognized	(221)		(538)
Qualified Pension Plans [Member] | Progress Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Prefunded pension cost	25	[1]
Accrued pension liability			(173)
Net amount recognized	25		(173)
Qualified Pension Plans [Member] | Progress Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(159)		(210)
Net amount recognized	(159)		(210)
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(81)		(62)
Net amount recognized	(81)		(62)
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(57)		(31)
Net amount recognized	(57)		(31)
Non Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(335)	[2]	(160)	[2]
Amounts recognized in other within current liabilities	30		17
Non Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(16)	[3]	(18)	[3]
Amounts recognized in other within current liabilities	3		3
Non Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(176)	[4]	(177)	[4]
Amounts recognized in other within current liabilities	11		10
Non Qualified Pension Plans [Member] | Progress Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(38)	[5]	(39)	[5]
Amounts recognized in other within current liabilities	2		2
Non Qualified Pension Plans [Member] | Progress Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(45)	[6]	(44)	[6]
Amounts recognized in other within current liabilities	3		3
Non Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(4)	[7]	(4)	[7]
Amounts recognized in other within current liabilities			1
Non Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(5)	[8]	(5)	[8]
Amounts recognized in other within current liabilities			1
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(1,596)	[2]	(486)	[2]
Amounts recognized in other within current liabilities	50		3
Other Postretirement Benefit Plans Defined Benefit [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(182)	[3]	(192)	[3]
Other Postretirement Benefit Plans Defined Benefit [Member] | Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(1,128)	[4]	(804)	[4]
Amounts recognized in other within current liabilities	47		22
Other Postretirement Benefit Plans Defined Benefit [Member] | Progress Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(612)	[5]	(407)	[5]
Amounts recognized in other within current liabilities	23		19
Other Postretirement Benefit Plans Defined Benefit [Member] | Progress Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(413)	[6]	(331)	[6]
Amounts recognized in other within current liabilities	20
Other Postretirement Benefit Plans Defined Benefit [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	(41)	[7]	(52)	[7]
Amounts recognized in other within current liabilities	2		2
Other Postretirement Benefit Plans Defined Benefit [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	$ (119)	[8]	$ (121)	[8]

[1] Included in Other within Investments and Other Assets on the Consolidated Balance Sheets.

[2] Duke Energy amount includes $50 million and $3 million recognized in Other within Current Liabilities on the Consolidated Balance Sheets as of December 31, 2012 and 2011, respectively.

[3] Duke Energy Carolinas amount includes an insignificant amount recognized in Other within Current Liabilities on the Consolidated Balance Sheets as of December 31, 2012 and 2011, respectively.

[4] Progress Energy amount includes $47 million and $22 million recognized in Other within Current Liabilities on the Consolidated Balance Sheets as of December 31, 2012 and 2011, respectively.

[5] Progress Energy Carolinas amount includes $23 million and $19 million recognized in Other within Current Liabilities on the Consolidated Balance Sheets as of December 31, 2012 and 2011, respectively.

[6] Progress Energy Florida amount includes $20 million and zero recognized in Other within Current Liabilities on the Balance Sheets as of December 31, 2012 and 2011, respectively.

[7] Duke Energy Ohio amount includes $2 million and $2 million recognized in Other within Current Liabilities on the Consolidated Balance Sheets as of December 31, 2012 and 2011, respectively.

[8] Duke Energy Indiana amount includes an insignificant amount recognized in Other within Current Liabilities on the Consolidated Balance Sheets as of December 31, 2012 and 2011, respectively.