Investments in Debt and Equity Securities (Available-For-Sale Investments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	$ 1,884		$ 1,216
Gross Unrealized Holding Losses	47		30
Estimated Fair Value	5,551		4,932
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	209		117		79
Realized losses	65		19		37
Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,852		1,199
Gross Unrealized Holding Losses	36		23
Estimated Fair Value	5,133		4,263
Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	110		105
Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,813		1,132
Gross Unrealized Holding Losses	10		19
Estimated Fair Value	3,579		2,837
Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	8		21
Gross Unrealized Holding Losses	6		1
Estimated Fair Value	400		338
Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2		12
Gross Unrealized Holding Losses	6		1
Estimated Fair Value	160		194
Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	7		24
Gross Unrealized Holding Losses	12		1
Estimated Fair Value	730		625
Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	22		10
Gross Unrealized Holding Losses	2		1
Estimated Fair Value	154		164
Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	32	[1]	17	[1]
Gross Unrealized Holding Losses	11	[1]	7	[1]
Estimated Fair Value	418	[1]	669	[1]
Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	21		17
Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	29		10
Estimated Fair Value	91		63
Other Classification [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1		2
Gross Unrealized Holding Losses	1
Estimated Fair Value	99		381
Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2		4
Gross Unrealized Holding Losses	2		1
Estimated Fair Value	79		70
Other Classification [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	17		23
Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Gross Unrealized Holding Losses	8		6
Estimated Fair Value	111		115
Duke Energy Carolinas [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,004		632
Gross Unrealized Holding Losses	23		9
Estimated Fair Value	2,837		2,364
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	115		89		71
Realized losses	12		6		35
Duke Energy Carolinas [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,004		632
Gross Unrealized Holding Losses	22		8
Estimated Fair Value	2,834		2,361
Duke Energy Carolinas [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	42		40
Duke Energy Carolinas [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	974		600
Gross Unrealized Holding Losses	6		5
Estimated Fair Value	1,964		1,592
Duke Energy Carolinas [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	5		11
Gross Unrealized Holding Losses	5		1
Estimated Fair Value	274		250
Duke Energy Carolinas [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			2
Gross Unrealized Holding Losses	2
Estimated Fair Value	54		40
Duke Energy Carolinas [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3		10
Gross Unrealized Holding Losses	7
Estimated Fair Value	354		304
Duke Energy Carolinas [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	22		9
Gross Unrealized Holding Losses	2		2
Estimated Fair Value	146		135
Duke Energy Carolinas [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	[2]	1	[2]
Estimated Fair Value	3	[2]	3	[2]
Duke Energy Carolinas [Member] | Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1		1
Estimated Fair Value	3		3
Progress Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	849		570
Gross Unrealized Holding Losses	14		15
Estimated Fair Value	2,358		1,959
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	90		34		30
Realized losses	46		18		33
Progress Energy [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	848		567
Gross Unrealized Holding Losses	14		15
Estimated Fair Value	2,299		1,902
Progress Energy [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	68		65
Progress Energy [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	839		532
Gross Unrealized Holding Losses	4		14
Estimated Fair Value	1,615		1,245
Progress Energy [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3		9
Gross Unrealized Holding Losses	1
Estimated Fair Value	126		89
Progress Energy [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2		11
Gross Unrealized Holding Losses	4		1
Estimated Fair Value	106		154
Progress Energy [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4		14
Gross Unrealized Holding Losses	5
Estimated Fair Value	376		321
Progress Energy [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Estimated Fair Value	8		28
Progress Energy [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1	[1]	3	[1]
Estimated Fair Value	59	[1]	57	[1]
Progress Energy [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	20		17
Progress Energy [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1		3
Estimated Fair Value	39		40
Duke Energy Progress [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	544		363
Gross Unrealized Holding Losses	11		11
Estimated Fair Value	1,540		1,278
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	58		21		13
Realized losses	26		8		16
Duke Energy Progress [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	544		363
Gross Unrealized Holding Losses	11		11
Estimated Fair Value	1,538		1,275
Duke Energy Progress [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	48		55
Duke Energy Progress [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	535		337
Gross Unrealized Holding Losses	3		11
Estimated Fair Value	1,069		811
Duke Energy Progress [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3		8
Gross Unrealized Holding Losses	1
Estimated Fair Value	80		78
Duke Energy Progress [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2		4
Gross Unrealized Holding Losses	4
Estimated Fair Value	104		80
Duke Energy Progress [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4		13
Gross Unrealized Holding Losses	3
Estimated Fair Value	232		241
Duke Energy Progress [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Estimated Fair Value	5		10
Duke Energy Progress [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	2	[1]	3	[1]
Duke Energy Progress [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	2		3
Duke Energy Florida [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	305		207
Gross Unrealized Holding Losses	3		4
Estimated Fair Value	803		668
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	32		13		17
Realized losses	20		9		17
Duke Energy Florida [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	304		204
Gross Unrealized Holding Losses	3		4
Estimated Fair Value	761		627
Duke Energy Florida [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	20		10
Duke Energy Florida [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	304		194
Gross Unrealized Holding Losses	1		4
Estimated Fair Value	546		434
Duke Energy Florida [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Estimated Fair Value	46		11
Duke Energy Florida [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			7
Estimated Fair Value	2		74
Duke Energy Florida [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Gross Unrealized Holding Losses	2
Estimated Fair Value	144		80
Duke Energy Florida [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Estimated Fair Value	3		18
Duke Energy Florida [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1	[3]	3	[3]
Estimated Fair Value	42	[3]	41	[3]
Duke Energy Florida [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	3		1
Duke Energy Florida [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1		3
Estimated Fair Value	39		40
Duke Energy Indiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	24		10
Gross Unrealized Holding Losses	1
Estimated Fair Value	94		78
Duke Energy Indiana [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	24	[1]	10	[1]
Gross Unrealized Holding Losses	1	[1]
Estimated Fair Value	94	[1]	78	[1]
Duke Energy Indiana [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1
Duke Energy Indiana [Member] | Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	24		9
Estimated Fair Value	65		50
Duke Energy Indiana [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains			1
Gross Unrealized Holding Losses	1
Estimated Fair Value	$ 28		$ 28

[1] These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

[2] These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.

[3] These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance sheets.