Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	$ 976	$ 747
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,544	1,077
Equity component of AFUDC	(82)	(116)
(Gains) losses on sales of other assets	8	(7)
Impairment of other long-lived assets	386	408
Deferred income taxes	397	230
Equity in earnings of unconsolidated affiliates	(58)	(85)
Voluntary opportunity cost deferral	0	(101)
Accrued pension and other post-retirement benefit costs	172	57
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	40	(10)
Receivables	(144)	61
Inventory	84	(165)
Other current assets	(43)	105
Increase (decrease) in [Abstract]
Accounts payable	(308)	(102)
Taxes accrued	95	(67)
Other current liabilities	4	34
Other assets	(175)	22
Other liabilities	(53)	(86)
Net cash provided by (used in) operating activities	2,843	2,002
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(2,715)	(2,252)
Investment expenditures	(49)	(9)
Acquisitions	0	(36)
Purchases of available-for-sale securities	(2,827)	(1,240)
Proceeds from sales and maturities of available-for-sale securities	2,775	1,155
Net proceeds from the sales of other assets, and sales of and collections on notes receivable	38	23
Change in restricted cash	188	(51)
Other	28	19
Net cash (used in) provided by investing activities	(2,562)	(2,391)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	1,832	721
Proceeds from the issuance of common stock related to employee benefit plans	7	14
Payments for the redemption of long-term debt	(1,538)	(878)
Payments for the redemption of preferred stock	(96)	0
Notes payable and commercial paper	763	631
Distributions to noncontrolling interests	(8)	(5)
Dividends paid	(1,085)	(670)
Other	(9)	(8)
Net cash provided by (used in) financing activities	(134)	(195)
Net increase (decrease) in cash and cash equivalents	147	(584)
Cash and cash equivalents at beginning of period	1,424	2,110
Cash and cash equivalents at end of period	1,571	1,526
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	480	216
Dividends declared but not paid	551	344
Extinguishment of debt related to investment in Attiki Gas Supply, S.A.		66
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	425	477
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	569	569
Equity component of AFUDC	(47)	(74)
(Gains) losses on sales of other assets	(2)	(6)
Deferred income taxes	247	275
Voluntary opportunity cost deferral	0	(101)
Accrued pension and other post-retirement benefit costs	20	21
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	(7)	1
Receivables	(3)	51
Receivables from affiliated companies	(46)	2
Inventory	(12)	(99)
Other current assets	(14)	8
Increase (decrease) in [Abstract]
Accounts payable	(44)	(184)
Accounts payable to affiliated companies	(6)	(60)
Taxes accrued	(5)	(17)
Other current liabilities	(50)	76
Other assets	(68)	(40)
Other liabilities	(41)	(74)
Net cash provided by (used in) operating activities	916	825
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(804)	(1,006)
Purchases of available-for-sale securities	(1,122)	(607)
Proceeds from sales and maturities of available-for-sale securities	1,098	591
Notes receivable from affiliated companies	167	679
Other	(10)	(1)
Net cash (used in) provided by investing activities	(671)	(344)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Payments for the redemption of long-term debt	0	(751)
Dividends paid to parent	(249)	0
Other	(2)	(1)
Net cash provided by (used in) financing activities	(251)	(752)
Net increase (decrease) in cash and cash equivalents	(6)	(271)
Cash and cash equivalents at beginning of period	19	289
Cash and cash equivalents at end of period	13	18
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	125	104
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	137	216
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	480	459
Equity component of AFUDC	(27)	(49)
(Gains) losses on sales of other assets	4	(19)
Impairment of other long-lived assets	366	0
Deferred income taxes	71	169
Accrued pension and other post-retirement benefit costs	105	82
Contributions to qualified pension plans	0	(42)
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	23	(63)
Receivables	(148)	(6)
Receivables from affiliated companies	12	0
Inventory	69	8
Other current assets	(33)	(72)
Increase (decrease) in [Abstract]
Accounts payable	(203)	26
Accounts payable to affiliated companies	48	0
Taxes accrued	124	107
Other current liabilities	169	(25)
Other assets	(126)	1
Other liabilities	88	(84)
Net cash provided by (used in) operating activities	1,159	708
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(1,295)	(1,118)
Purchases of available-for-sale securities	(978)	(625)
Proceeds from sales and maturities of available-for-sale securities	960	610
Change in restricted cash	0	(14)
Notes receivable from affiliated companies	(101)	0
Other	21	68
Net cash (used in) provided by investing activities	(1,393)	(1,079)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	545	1,432
Proceeds from the issuance of common stock related to employee benefit plans	0	6
Payments for the redemption of long-term debt	(788)	(455)
Payments for the redemption of preferred stock	(96)	0
Payments of short-term debt with original maturities greater than 90 days	0	(65)
Proceeds from issuance of short-term debt with original maturities greater than 90 days	0	65
Notes payable and commercial paper	0	(326)
Notes payable to affiliated companies	403	0
Distributions to noncontrolling interests	(2)	(4)
Dividends paid	0	(446)
Other	(5)	7
Net cash provided by (used in) financing activities	57	214
Net increase (decrease) in cash and cash equivalents	(177)	(157)
Cash and cash equivalents at beginning of period	231	230
Cash and cash equivalents at end of period	54	73
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	310	265
Capital expenditures financed through capital leases	0	116
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	187	83
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	324	326
Equity component of AFUDC	(23)	(32)
(Gains) losses on sales of other assets	0	(1)
Impairment of other long-lived assets	22	0
Deferred income taxes	146	95
Accrued pension and other post-retirement benefit costs	48	33
Contributions to qualified pension plans	0	(22)
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	(12)	(38)
Receivables	(49)	(5)
Receivables from affiliated companies	(3)	1
Inventory	23	0
Other current assets	(69)	(38)
Increase (decrease) in [Abstract]
Accounts payable	(142)	12
Accounts payable to affiliated companies	27	27
Taxes accrued	41	29
Other current liabilities	(49)	11
Other assets	(53)	(13)
Other liabilities	5	(18)
Net cash provided by (used in) operating activities	423	450
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(725)	(724)
Purchases of available-for-sale securities	(318)	(271)
Proceeds from sales and maturities of available-for-sale securities	299	256
Notes receivable from affiliated companies	0	(229)
Other	3	60
Net cash (used in) provided by investing activities	(741)	(908)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	545	988
Payments for the redemption of long-term debt	(50)	(1)
Payments for the redemption of preferred stock	(62)	0
Notes payable and commercial paper	0	(188)
Notes payable to affiliated companies	(107)	(31)
Dividends paid to parent	0	(310)
Dividends paid on preferred stock	(1)	(1)
Other	(5)	2
Net cash provided by (used in) financing activities	320	459
Net increase (decrease) in cash and cash equivalents	2	1
Cash and cash equivalents at beginning of period	18	20
Cash and cash equivalents at end of period	20	21
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	216	162
Capital expenditures financed through capital leases	0	116
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	53	211
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	145	121
Equity component of AFUDC	(4)	(17)
(Gains) losses on sales of other assets	(1)	(1)
Impairment of other long-lived assets	345	0
Deferred income taxes	34	74
Accrued pension and other post-retirement benefit costs	43	33
Contributions to qualified pension plans	0	(20)
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	33	21
Receivables	(85)	(12)
Receivables from affiliated companies	20	(9)
Inventory	44	7
Other current assets	(44)	(58)
Increase (decrease) in [Abstract]
Accounts payable	26	44
Accounts payable to affiliated companies	(3)	17
Taxes accrued	127	81
Other current liabilities	232	(31)
Other assets	(76)	19
Other liabilities	23	(80)
Net cash provided by (used in) operating activities	912	400
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(564)	(376)
Purchases of available-for-sale securities	(661)	(353)
Proceeds from sales and maturities of available-for-sale securities	661	353
Notes receivable from affiliated companies	207	0
Other	9	6
Net cash (used in) provided by investing activities	(348)	(370)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Payments for the redemption of long-term debt	(429)	(4)
Payments for the redemption of preferred stock	(34)	0
Payments of short-term debt with original maturities greater than 90 days	0	(65)
Proceeds from issuance of short-term debt with original maturities greater than 90 days	0	65
Notes payable and commercial paper	0	(89)
Notes payable to affiliated companies	11	234
Dividends paid to parent	(225)	(170)
Dividends paid on preferred stock	0	(1)
Other	0	3
Net cash provided by (used in) financing activities	(677)	(27)
Net increase (decrease) in cash and cash equivalents	(113)	3
Cash and cash equivalents at beginning of period	131	16
Cash and cash equivalents at end of period	18	19
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	93	99
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	37	119
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	179	165
(Gains) losses on sales of other assets	(4)	(2)
Impairment of other long-lived assets	0	0
Deferred income taxes	15	69
Accrued pension and other post-retirement benefit costs	9	6
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	22	(11)
Receivables	(19)	18
Receivables from affiliated companies	(8)	33
Inventory	21	(20)
Other current assets	(19)	29
Increase (decrease) in [Abstract]
Accounts payable	(36)	(22)
Accounts payable to affiliated companies	(4)	(11)
Taxes accrued	(49)	(22)
Other current liabilities	(2)	(14)
Other assets	(9)	(11)
Other liabilities	(23)	(75)
Net cash provided by (used in) operating activities	110	251
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(222)	(252)
Net proceeds from the sales of other assets, and sales of and collections on notes receivable	11	82
Change in restricted cash	0	(25)
Notes receivable from affiliated companies	(18)	(130)
Other	0	1
Net cash (used in) provided by investing activities	(229)	(324)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Payments for the redemption of long-term debt	(253)	(4)
Notes payable to affiliated companies	357	0
Other	(1)	0
Net cash provided by (used in) financing activities	103	(4)
Net increase (decrease) in cash and cash equivalents	(16)	(77)
Cash and cash equivalents at beginning of period	31	99
Cash and cash equivalents at end of period	15	22
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	18	37
Transfer of Vermillion Generating Station	0	28
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	172	(90)
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	158	195
Equity component of AFUDC	(7)	(39)
Impairment of other long-lived assets	0	400
Deferred income taxes	92	(73)
Accrued pension and other post-retirement benefit costs	12	8
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	0	0
Receivables	(2)	10
Receivables from affiliated companies	(6)	(2)
Inventory	(17)	(28)
Other current assets	(1)	19
Increase (decrease) in [Abstract]
Accounts payable	(7)	34
Accounts payable to affiliated companies	(13)	(34)
Taxes accrued	(8)	(25)
Other current liabilities	(10)	17
Other assets	11	26
Other liabilities	(18)	(35)
Net cash provided by (used in) operating activities	356	383
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(281)	(439)
Purchases of available-for-sale securities	(5)	(8)
Proceeds from sales and maturities of available-for-sale securities	5	10
Notes receivable from affiliated companies	(21)	0
Other	1	(2)
Net cash (used in) provided by investing activities	(301)	(439)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	0	250
Payments for the redemption of long-term debt	(1)	(2)
Notes payable to affiliated companies	(81)	(187)
Other	(1)	(2)
Net cash provided by (used in) financing activities	(83)	59
Net increase (decrease) in cash and cash equivalents	(28)	3
Cash and cash equivalents at beginning of period	36	16
Cash and cash equivalents at end of period	8	19
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	32	46
Transfer of Vermillion Generating Station	$ 0	$ 26