Condensed Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 634	$ 299
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	762	544
Equity component of AFUDC	(42)	(59)
(Gains) losses on sales of other assets	(2)	(3)
Impairment of other long-lived assets	0	407
Deferred income taxes	353	65
Equity in earnings of unconsolidated affiliates	(36)	(45)
Voluntary opportunity cost deferral	0	(101)
Accrued pension and other post-retirement benefit costs	87	28
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	36	(2)
Receivables	(118)	172
Inventory	126	(162)
Other current assets	(38)	110
Increase (decrease) in
Accounts payable	(246)	(270)
Taxes accrued	(31)	(62)
Other current liabilities	(312)	10
Other assets	(78)	3
Other liabilities	(4)	(62)
Net cash provided by (used in) operating activities	1,091	872
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,375)	(988)
Investment expenditures	(3)	(13)
Acquisitions	(32)	(42)
Purchases of available-for-sale securities	(1,255)	(948)
Proceeds from sales and maturities of available-for-sale securities	1,179	821
Net proceeds from the sales of other assets, and sales of and collections on notes receivable	20	17
Change in restricted cash	(34)	(35)
Other	35	8
Net cash (used in) provided by investing activities	(1,465)	(1,180)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,009	392
Proceeds from the issuance of common stock related to employee benefit plans	5	8
Payments for the redemption of long-term debt	(747)	(821)
Payments for the redemption of preferred stock	(96)	0
Notes payable and commercial paper	627	28
Distributions to noncontrolling interests	(3)	(1)
Dividends paid	(542)	(335)
Other	(7)	(2)
Net cash provided by (used in) financing activities	246	(731)
Net increase (decrease) in cash and cash equivalents	(128)	(1,039)
Cash and cash equivalents at beginning of period	1,424	2,110
Cash and cash equivalents at end of period	1,296	1,071
Significant Non-cash Transactions
Accrued capital expenditures	465	270
Extinguishment of debt related to investment in Attiki Gas Supply, S.A.		66
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	244	266
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	281	288
Equity component of AFUDC	(26)	(36)
(Gains) losses on sales of other assets	(2)	(3)
Deferred income taxes	146	154
Voluntary opportunity cost deferral	0	(101)
Accrued pension and other post-retirement benefit costs	10	10
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(7)	0
Receivables	(8)	134
Receivables from affiliated companies	(54)	(17)
Inventory	50	(100)
Other current assets	(25)	(3)
Increase (decrease) in
Accounts payable	(16)	(196)
Accounts payable to affiliated companies	(16)	(37)
Taxes accrued	(48)	(65)
Other current liabilities	(34)	109
Other assets	(28)	(18)
Other liabilities	(15)	(32)
Net cash provided by (used in) operating activities	452	353
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(435)	(483)
Purchases of available-for-sale securities	(504)	(627)
Proceeds from sales and maturities of available-for-sale securities	492	615
Notes receivable from affiliated companies	(15)	625
Other	(3)	(5)
Net cash (used in) provided by investing activities	(465)	125
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	0	(751)
Other	(1)	(1)
Net cash provided by (used in) financing activities	(1)	(752)
Net increase (decrease) in cash and cash equivalents	(14)	(274)
Cash and cash equivalents at beginning of period	19	289
Cash and cash equivalents at end of period	5	15
Significant Non-cash Transactions
Accrued capital expenditures	132	115
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	154	152
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	235	195
Equity component of AFUDC	(13)	(24)
(Gains) losses on sales of other assets	0	(19)
Impairment of other long-lived assets	0	0
Deferred income taxes	118	106
Accrued pension and other post-retirement benefit costs	53	38
Contributions to qualified pension plans	0	(18)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	12	(60)
Receivables	(25)	75
Receivables from affiliated companies	(3)	0
Inventory	36	(8)
Other current assets	(115)	(18)
Increase (decrease) in
Accounts payable	(191)	(23)
Accounts payable to affiliated companies	34	0
Taxes accrued	72	60
Other current liabilities	(95)	(72)
Other assets	(76)	(34)
Other liabilities	69	(35)
Net cash provided by (used in) operating activities	265	315
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(622)	(600)
Purchases of available-for-sale securities	(401)	(363)
Proceeds from sales and maturities of available-for-sale securities	391	359
Change in restricted cash	0	(14)
Notes receivable from affiliated companies	(20)	0
Other	9	66
Net cash (used in) provided by investing activities	(643)	(552)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	496	444
Proceeds from the issuance of common stock related to employee benefit plans	0	3
Payments for the redemption of long-term debt	(736)	(1)
Payments for the redemption of preferred stock	(96)	0
Proceeds from issuance of short-term debt with original maturities greater than 90 days	0	65
Notes payable and commercial paper	0	321
Notes payable to affiliated companies	525	0
Distributions to noncontrolling interests	(3)	(3)
Dividends paid	0	(260)
Other	(4)	3
Net cash provided by (used in) financing activities	182	572
Net increase (decrease) in cash and cash equivalents	(196)	335
Cash and cash equivalents at beginning of period	231	230
Cash and cash equivalents at end of period	35	565
Significant Non-cash Transactions
Accrued capital expenditures	248	225
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	110	52
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	175	161
Equity component of AFUDC	(11)	(15)
(Gains) losses on sales of other assets	0	(1)
Deferred income taxes	86	46
Accrued pension and other post-retirement benefit costs	24	13
Contributions to qualified pension plans	0	(10)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(17)	(3)
Receivables	(8)	51
Receivables from affiliated companies	(13)	1
Inventory	20	(5)
Other current assets	(25)	(28)
Increase (decrease) in
Accounts payable	(87)	4
Accounts payable to affiliated companies	81	15
Taxes accrued	32	23
Other current liabilities	(55)	(42)
Other assets	(33)	(18)
Other liabilities	14	2
Net cash provided by (used in) operating activities	293	246
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(395)	(391)
Purchases of available-for-sale securities	(196)	(138)
Proceeds from sales and maturities of available-for-sale securities	188	133
Other	0	61
Net cash (used in) provided by investing activities	(403)	(335)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	496	0
Payments for the redemption of long-term debt	(1)	0
Payments for the redemption of preferred stock	(62)	0
Notes payable and commercial paper	0	253
Notes payable to affiliated companies	(326)	11
Dividends paid to parent	0	(175)
Dividends paid on preferred stock	0	(1)
Other	(4)	2
Net cash provided by (used in) financing activities	103	90
Net increase (decrease) in cash and cash equivalents	(7)	1
Cash and cash equivalents at beginning of period	18	20
Cash and cash equivalents at end of period	11	21
Significant Non-cash Transactions
Accrued capital expenditures	149	162
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	110	128
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	54	28
Equity component of AFUDC	(2)	(9)
(Gains) losses on sales of other assets	0	(1)
Impairment of other long-lived assets	0	0
Deferred income taxes	70	53
Accrued pension and other post-retirement benefit costs	22	15
Contributions to qualified pension plans	0	(8)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	28	(9)
Receivables	5	12
Receivables from affiliated companies	(44)	(18)
Inventory	15	(4)
Other current assets	(129)	3
Increase (decrease) in
Accounts payable	(50)	16
Accounts payable to affiliated companies	21	17
Taxes accrued	76	34
Other current liabilities	(13)	(15)
Other assets	(42)	(13)
Other liabilities	(5)	(40)
Net cash provided by (used in) operating activities	116	189
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(223)	(200)
Purchases of available-for-sale securities	(205)	(225)
Proceeds from sales and maturities of available-for-sale securities	203	225
Notes receivable from affiliated companies	207	(6)
Other	0	6
Net cash (used in) provided by investing activities	(18)	(200)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	(426)	(1)
Payments for the redemption of preferred stock	(34)	0
Proceeds from issuance of short-term debt with original maturities greater than 90 days	0	65
Notes payable and commercial paper	0	62
Notes payable to affiliated companies	238	(8)
Dividends paid to parent	0	(105)
Dividends paid on preferred stock	0	(1)
Other	0	1
Net cash provided by (used in) financing activities	(222)	13
Net increase (decrease) in cash and cash equivalents	(124)	2
Cash and cash equivalents at beginning of period	131	16
Cash and cash equivalents at end of period	7	18
Significant Non-cash Transactions
Accrued capital expenditures	95	60
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	(21)	74
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	89	84
(Gains) losses on sales of other assets	0	(1)
Impairment of other long-lived assets	0	2
Deferred income taxes	(12)	44
Accrued pension and other post-retirement benefit costs	5	3
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	38	(48)
Receivables	(17)	25
Receivables from affiliated companies	(41)	30
Inventory	11	(8)
Other current assets	8	42
Increase (decrease) in
Accounts payable	(5)	(30)
Accounts payable to affiliated companies	3	46
Taxes accrued	(37)	(24)
Other current liabilities	13	6
Other assets	(10)	(8)
Other liabilities	(10)	(57)
Net cash provided by (used in) operating activities	14	180
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(105)	(121)
Net proceeds from the sales of other assets, and sales of and collections on notes receivable	0	82
Change in restricted cash	0	6
Notes receivable from affiliated companies	(3)	(218)
Net cash (used in) provided by investing activities	(108)	(251)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	(2)	(2)
Notes payable to affiliated companies	92	0
Net cash provided by (used in) financing activities	90	(2)
Net increase (decrease) in cash and cash equivalents	(4)	(73)
Cash and cash equivalents at beginning of period	31	99
Cash and cash equivalents at end of period	27	26
Significant Non-cash Transactions
Accrued capital expenditures	19	34
Transfer of Vermillion Generating Station		(28)
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	90	(167)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	79	97
Equity component of AFUDC	(3)	(21)
Impairment of other long-lived assets	0	400
Deferred income taxes	45	(116)
Accrued pension and other post-retirement benefit costs	5	4
(Increase) decrease in
Receivables	2	9
Receivables from affiliated companies	(39)	(20)
Inventory	6	(34)
Other current assets	12	8
Increase (decrease) in
Accounts payable	(6)	7
Accounts payable to affiliated companies	(4)	8
Taxes accrued	18	(8)
Other current liabilities	(16)	(4)
Other assets	20	9
Other liabilities	(11)	(19)
Net cash provided by (used in) operating activities	198	153
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(156)	(273)
Purchases of available-for-sale securities	(2)	(4)
Proceeds from sales and maturities of available-for-sale securities	2	4
Other	0	1
Net cash (used in) provided by investing activities	(156)	(272)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	0	250
Payments for the redemption of long-term debt	(1)	(1)
Notes payable to affiliated companies	(54)	(122)
Other	0	(2)
Net cash provided by (used in) financing activities	(55)	125
Net increase (decrease) in cash and cash equivalents	(13)	6
Cash and cash equivalents at beginning of period	36	16
Cash and cash equivalents at end of period	23	22
Significant Non-cash Transactions
Accrued capital expenditures	28	72
Transfer of Vermillion Generating Station	$ 0	$ 26