Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	$ (93)	$ 634
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	884	762
Equity component of AFUDC	(28)	(42)
(Gains) losses on sales of other assets		(2)
Impairment of other long-lived assets	1,382
Deferred income taxes	(178)	353
Equity in earnings of unconsolidated affiliates	(36)	(36)
Accrued pension and other post-retirement benefit costs	27	87
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	45	36
Receivables	29	(118)
Inventory	272	126
Other current assets	(297)	(38)
Increase (decrease) in [Abstract]
Accounts payable	(97)	(246)
Taxes accrued	(175)	(31)
Other current liabilities	(346)	(312)
Other assets	(22)	(78)
Other liabilities	6	(4)
Net cash provided by (used in) operating activities	1,373	1,091
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(1,232)	(1,375)
Investment expenditures	(36)	(3)
Acquisitions		(32)
Purchases of available-for-sale securities	(967)	(1,255)
Proceeds from sales and maturities of available-for-sale securities	1,004	1,179
Net proceeds from the sales of other assets, and sales of and collections on notes receivable	4	20
Change in restricted cash	(27)	(34)
Other	(32)	35
Net cash (used in) provided by investing activities	(1,286)	(1,465)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	875	1,009
Proceeds from the issuance of common stock related to employee benefit plans	19	5
Payments for the redemption of long-term debt	(1,287)	(747)
Payments for the redemption of preferred stock		(96)
Notes payable and commercial paper	898	627
Distributions to noncontrolling interests	(3)	(3)
Dividends paid	(553)	(542)
Other	(6)	(7)
Net cash provided by (used in) financing activities	(57)	246
Net increase (decrease) in cash and cash equivalents	30	(128)
Cash and cash equivalents at beginning of period	1,501	1,424
Cash and cash equivalents at end of period	1,531	1,296
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	361	465
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	286	244
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	309	281
Equity component of AFUDC	(22)	(26)
(Gains) losses on sales of other assets	0	(2)
Deferred income taxes	87	146
Accrued pension and other post-retirement benefit costs	6	10
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	3	(7)
Receivables	11	(8)
Receivables from affiliated companies	(27)	(54)
Inventory	181	50
Other current assets	(59)	(25)
Increase (decrease) in [Abstract]
Accounts payable	(100)	(16)
Accounts payable to affiliated companies	21	(16)
Taxes accrued	(3)	(48)
Other current liabilities	(26)	(34)
Other assets	14	(28)
Other liabilities	(9)	(15)
Net cash provided by (used in) operating activities	672	452
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(426)	(435)
Purchases of available-for-sale securities	(584)	(504)
Proceeds from sales and maturities of available-for-sale securities	579	492
Notes receivable from affiliated companies	(115)	(15)
Other	(6)	(3)
Net cash (used in) provided by investing activities	(552)	(465)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Dividends to parent	(126)	0
Other	0	(1)
Net cash provided by (used in) financing activities	(126)	(1)
Net increase (decrease) in cash and cash equivalents	(6)	(14)
Cash and cash equivalents at beginning of period	23	19
Cash and cash equivalents at end of period	17	5
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	133	132
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	203	154
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	316	235
Equity component of AFUDC	(1)	(13)
(Gains) losses on sales of other assets	(1)
Deferred income taxes	183	118
Accrued pension and other post-retirement benefit costs	7	53
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	13	12
Receivables	(45)	(25)
Receivables from affiliated companies		(3)
Inventory	72	36
Other current assets	(134)	(115)
Increase (decrease) in [Abstract]
Accounts payable	(53)	(191)
Accounts payable to affiliated companies	114	34
Taxes accrued	3	72
Other current liabilities	(116)	(95)
Other assets	(52)	(76)
Other liabilities	(6)	69
Net cash provided by (used in) operating activities	503	265
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(475)	(622)
Purchases of available-for-sale securities	(266)	(401)
Proceeds from sales and maturities of available-for-sale securities	269	391
Notes receivable from affiliated companies	(101)	(20)
Other	(25)	9
Net cash (used in) provided by investing activities	(598)	(643)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	875	496
Payments for the redemption of long-term debt	(469)	(736)
Payments for the redemption of preferred stock		(96)
Notes payable to affiliated companies	(291)	525
Distributions to noncontrolling interests	(3)	(3)
Other	(39)	(4)
Net cash provided by (used in) financing activities	73	182
Net increase (decrease) in cash and cash equivalents	(22)	(196)
Cash and cash equivalents at beginning of period	58	231
Cash and cash equivalents at end of period	36	35
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	158	248
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	133	110
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	183	175
Equity component of AFUDC	(2)	(11)
(Gains) losses on sales of other assets	(1)
Deferred income taxes	117	86
Accrued pension and other post-retirement benefit costs	(2)	24
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	6	(17)
Receivables	10	(8)
Receivables from affiliated companies	(5)	(13)
Inventory	53	20
Other current assets	(183)	(25)
Increase (decrease) in [Abstract]
Accounts payable	(37)	(87)
Accounts payable to affiliated companies	139	81
Taxes accrued		32
Other current liabilities	(41)	(55)
Other assets	(13)	(33)
Other liabilities	(1)	14
Net cash provided by (used in) operating activities	356	293
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(299)	(395)
Purchases of available-for-sale securities	(151)	(196)
Proceeds from sales and maturities of available-for-sale securities	149	188
Notes receivable from affiliated companies	(65)
Other	(18)
Net cash (used in) provided by investing activities	(384)	(403)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	650	496
Payments for the redemption of long-term debt	(168)	(1)
Payments for the redemption of preferred stock		(62)
Notes payable to affiliated companies	(462)	(326)
Other	(4)	(4)
Net cash provided by (used in) financing activities	16	103
Net increase (decrease) in cash and cash equivalents	(12)	(7)
Cash and cash equivalents at beginning of period	21	18
Cash and cash equivalents at end of period	9	11
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	116	149
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	108	110
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	133	54
Equity component of AFUDC	0	(2)
Deferred income taxes	60	70
Accrued pension and other post-retirement benefit costs	7	22
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	5	28
Receivables	21	5
Receivables from affiliated companies	(7)	(44)
Inventory	20	15
Other current assets	68	(129)
Increase (decrease) in [Abstract]
Accounts payable	24	(50)
Accounts payable to affiliated companies	28	21
Taxes accrued	10	76
Other current liabilities	(63)	(13)
Other assets	(36)	(42)
Other liabilities	(13)	(5)
Net cash provided by (used in) operating activities	365	116
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(176)	(223)
Purchases of available-for-sale securities	(115)	(205)
Proceeds from sales and maturities of available-for-sale securities	120	203
Notes receivable from affiliated companies	(110)	207
Other	(8)	0
Net cash (used in) provided by investing activities	(289)	(18)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	225
Payments for the redemption of long-term debt	(1)	(426)
Payments for the redemption of preferred stock	0	(34)
Notes payable to affiliated companies	(181)	238
Dividends to parent	(124)
Other	(1)	0
Net cash provided by (used in) financing activities	(82)	(222)
Net increase (decrease) in cash and cash equivalents	(6)	(124)
Cash and cash equivalents at beginning of period	16	131
Cash and cash equivalents at end of period	10	7
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	42	95
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	(890)	(21)
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	92	89
Equity component of AFUDC	(1)
Impairment of other long-lived assets	1,417
Deferred income taxes	(501)	(12)
Accrued pension and other post-retirement benefit costs	1	5
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	39	38
Receivables	(16)	(17)
Receivables from affiliated companies	(6)	(41)
Inventory	29	11
Other current assets	(92)	8
Increase (decrease) in [Abstract]
Accounts payable	21	(5)
Accounts payable to affiliated companies	(13)	3
Taxes accrued	(38)	(37)
Other current liabilities	(7)	13
Other assets	(9)	(10)
Other liabilities	7	(10)
Net cash provided by (used in) operating activities	33	14
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(83)	(105)
Notes receivable from affiliated companies	(110)	(3)
Net cash (used in) provided by investing activities	(193)	(108)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Payments for the redemption of long-term debt	(1)	(2)
Notes payable to affiliated companies	263	92
Dividends to parent	(100)
Net cash provided by (used in) financing activities	162	90
Net increase (decrease) in cash and cash equivalents	2	(4)
Cash and cash equivalents at beginning of period	36	31
Cash and cash equivalents at end of period	38	27
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	24	19
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	113	90
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	103	79
Equity component of AFUDC	(4)	(3)
Deferred income taxes	(39)	45
Accrued pension and other post-retirement benefit costs	4	5
(Increase) decrease in [Abstract]
Receivables	(23)	2
Receivables from affiliated companies	10	(39)
Inventory	(10)	6
Other current assets	(41)	12
Increase (decrease) in [Abstract]
Accounts payable	(36)	(6)
Accounts payable to affiliated companies	12	(4)
Taxes accrued	110	18
Other current liabilities	(6)	(16)
Other assets	(3)	20
Other liabilities	50	(11)
Net cash provided by (used in) operating activities	240	198
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	(133)	(156)
Purchases of available-for-sale securities	(3)	(2)
Proceeds from sales and maturities of available-for-sale securities	3	2
Notes receivable from affiliated companies	(94)	0
Net cash (used in) provided by investing activities	(227)	(156)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Payments for the redemption of long-term debt	(1)	(1)
Notes payable to affiliated companies	0	(54)
Other	(1)	0
Net cash provided by (used in) financing activities	(2)	(55)
Net increase (decrease) in cash and cash equivalents	11	(13)
Cash and cash equivalents at beginning of period	15	36
Cash and cash equivalents at end of period	26	23
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	$ 32	$ 28