Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	$ 3,571	$ 2,644	$ 3,064
Net Income Attributable to Parent	3,748	2,666	3,059
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	5,176	4,696	4,046
Equity component of AFUDC	(139)	(221)	(237)
Losses (Gains) on sales of other assets	4	88	(33)
Impairment charges	(8)	402	282
Deferred income taxes	806	1,079	1,433
Equity in earnings of unconsolidated affiliates	(162)	(83)	(119)
Accrued pension and other post-retirement benefit costs	24	61	8
Contributions to qualified pension plans	(77)	(141)	(19)
Payments for asset retirement obligations	(746)	(533)	(571)
Payment for the disposal of other assets		(105)
Provision for rate refunds	60	425
Refund of AMT credit carryforwards	573
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(48)	22	18
Receivables	78	(345)	(83)
Inventory	(122)	156	268
Other current assets	10	(721)	(400)
Increase (decrease) in
Accounts payable	(164)	479	(204)
Taxes accrued	(224)	23	149
Other current liabilities	172	270	(482)
Other assets	(520)	(971)	(436)
Other liabilities	(55)	(39)	(60)
Net cash provided by (used in) operating activities	8,209	7,186	6,624
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(11,122)	(9,389)	(8,052)
Contributions to equity method investments	(324)	(416)	(414)
Return of investment capital	11	137	281
Purchases of debt and equity securities	(3,348)	(3,762)	(4,071)
Proceeds from sales and maturities of debt and equity securities	3,343	3,747	4,098
Other	(517)	(377)	(284)
Net cash used in investing activities	(11,957)	(10,060)	(8,442)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	7,091	5,299	6,909
Net proceeds from Issuance of Preferred Stock and Preference Stock	1,962
Proceeds from Issuance of Common Stock	384	1,838
Payments for the redemption of long-term debt	(3,476)	(2,906)	(2,316)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	397	472	319
Payments for the redemption of short-term debt with original maturities greater than 90 days	(479)	(282)	(272)
Notes payable and commercial paper	(298)	981	(409)
Contributions from noncontrolling interests	843	41
Dividends paid	(2,668)	(2,471)	(2,450)
Other	(26)	(12)	1
Net cash provided by financing activities	3,730	2,960	1,782
Net (decrease) increase in cash, cash equivalents, and restricted cash	(18)	86	(36)
Cash, cash equivalents, and restricted cash at beginning of period	591	505	541
Cash, cash equivalents, and restricted cash at end of period	573	591	505
Cash and cash equivalents at beginning of period	442
Cash and cash equivalents at end of period	311	442
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	2,195	2,086	1,963
Cash (received from) paid for income taxes	(651)	(266)	4
Significant non-cash transactions:
Accrued capital expenditures	1,356	1,112	1,032
Non-cash dividends	108	107
Duke Energy Carolinas
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net Income Attributable to Parent	1,403	1,071	1,214
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,671	1,487	1,409
Equity component of AFUDC	(42)	(73)	(106)
Losses (Gains) on sales of other assets		1	(1)
Impairment charges	17	192
Deferred income taxes	133	305	410
Accrued pension and other post-retirement benefit costs	(5)	4	(4)
Contributions to qualified pension plans	(7)	(46)
Payments for asset retirement obligations	(278)	(230)	(271)
Provision for rate refunds	36	182
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(8)	2	9
Receivables	(21)	(86)	(9)
Receivables from affiliated companies	68	(87)	68
Inventory	(48)	25	78
Other current assets	(73)	(161)	7
Increase (decrease) in
Accounts payable	(50)	168	23
Accounts payable to affiliated companies	(20)	21	(38)
Taxes accrued	(127)	(65)	86
Other current liabilities	127	89	(161)
Other assets	(31)	(179)	(49)
Other liabilities	(36)	(90)	(31)
Net cash provided by (used in) operating activities	2,709	2,530	2,634
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,714)	(2,706)	(2,524)
Purchases of debt and equity securities	(1,658)	(1,810)	(2,124)
Proceeds from sales and maturities of debt and equity securities	1,658	1,810	2,128
Notes receivable from affiliated companies			66
Other	(204)	(147)	(109)
Net cash used in investing activities	(2,918)	(2,853)	(2,563)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	886	1,983	569
Payments for the redemption of long-term debt	(6)	(1,205)	(116)
Notes payable to affiliated companies	(410)	335	104
Distributions to parent	(275)	(750)	(625)
Other	(1)	(23)	(1)
Net cash provided by financing activities	194	340	(69)
Net (decrease) increase in cash and cash equivalents	(15)	17	2
Cash and cash equivalents at beginning of period	33	16	14
Cash and cash equivalents at end of period	18	33	16
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	433	452	398
Cash (received from) paid for income taxes	122	89	193
Significant non-cash transactions:
Accrued capital expenditures	347	302	315
Progress Energy
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	1,327	1,033	1,268
Net Income Attributable to Parent	1,327	1,027	1,258
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	2,207	1,987	1,516
Equity component of AFUDC	(66)	(104)	(92)
Losses (Gains) on sales of other assets		(24)	(28)
Impairment charges	(24)	87	156
Deferred income taxes	433	358	703
Accrued pension and other post-retirement benefit costs	20	24	(28)
Contributions to qualified pension plans	(57)	(45)
Payments for asset retirement obligations	(412)	(230)	(248)
Provision for rate refunds	15	122
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(34)	18
Receivables	47	(207)	(89)
Receivables from affiliated companies	81	(137)	71
Inventory	62	121	125
Other current assets	184	(12)	(397)
Increase (decrease) in
Accounts payable	(4)	217	(260)
Accounts payable to affiliated companies	(50)	109	(97)
Taxes accrued	(74)	8	17
Other current liabilities	25	129	(166)
Other assets	(336)	(876)	(300)
Other liabilities	(135)	(34)	(98)
Net cash provided by (used in) operating activities	3,209	2,544	2,053
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(3,952)	(3,854)	(3,152)
Purchases of debt and equity securities	(1,511)	(1,753)	(1,806)
Proceeds from sales and maturities of debt and equity securities	1,504	1,769	1,824
Notes receivable from affiliated companies	(164)	240	(160)
Other	(190)	(162)	(59)
Net cash used in investing activities	(4,313)	(3,760)	(3,353)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	2,187	1,833	2,118
Payments for the redemption of long-term debt	(1,667)	(771)	(813)
Notes payable to affiliated companies	586	430	100
Dividends to parent		(250)	(124)
Other	12	(1)	(4)
Net cash provided by financing activities	1,118	1,241	1,277
Net (decrease) increase in cash, cash equivalents, and restricted cash	14	25	(23)
Cash, cash equivalents, and restricted cash at beginning of period	112	87	110
Cash, cash equivalents, and restricted cash at end of period	126	112	87
Cash and cash equivalents at beginning of period	67
Cash and cash equivalents at end of period	48	67
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	892	798	773
Cash (received from) paid for income taxes	(79)	(348)	(146)
Significant non-cash transactions:
Accrued capital expenditures	447	478	391
Equitization of certain notes payable to affiliates			1,047
Dividend to parent related to a legal entity restructuring			547
Duke Energy Progress
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net Income Attributable to Parent	805	667	715
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,329	1,183	936
Equity component of AFUDC	(60)	(57)	(47)
Losses (Gains) on sales of other assets		(9)	(5)
Impairment charges	12	33	19
Deferred income taxes	197	236	384
Accrued pension and other post-retirement benefit costs	4	15	(20)
Contributions to qualified pension plans	(3)	(25)
Payments for asset retirement obligations	(390)	(195)	(192)
Provision for rate refunds	12	122
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(6)	5	(4)
Receivables	21	(107)	(58)
Receivables from affiliated companies	(29)	(20)	2
Inventory	20	63	59
Other current assets	101	(201)	(75)
Increase (decrease) in
Accounts payable	32	219	(230)
Accounts payable to affiliated companies	(75)	99	(48)
Taxes accrued	(46)	(11)	(39)
Other current liabilities	68	46	(131)
Other assets	(198)	(447)	(53)
Other liabilities	29	12	(18)
Net cash provided by (used in) operating activities	1,823	1,628	1,195
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,108)	(2,220)	(1,715)
Purchases of debt and equity securities	(842)	(1,236)	(1,249)
Proceeds from sales and maturities of debt and equity securities	810	1,206	1,207
Notes receivable from affiliated companies			165
Other	(119)	(95)	(51)
Net cash used in investing activities	(2,259)	(2,345)	(1,643)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	1,269	845	812
Payments for the redemption of long-term debt	(605)	(3)	(470)
Notes payable to affiliated companies	(228)	54	240
Distributions to parent		(175)	(124)
Other	(1)	(1)	(1)
Net cash provided by financing activities	435	720	457
Net (decrease) increase in cash and cash equivalents	(1)	3	9
Cash and cash equivalents at beginning of period	23	20	11
Cash and cash equivalents at end of period	22	23	20
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	331	303	291
Cash (received from) paid for income taxes	(30)	(112)	59
Significant non-cash transactions:
Accrued capital expenditures	175	220	191
Duke Energy Florida
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net Income Attributable to Parent	692	554	712
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	869	793	570
Equity component of AFUDC	(6)	(47)	(45)
Losses (Gains) on sales of other assets		(1)	(1)
Impairment charges	(36)	54	138
Deferred income taxes	180	159	245
Accrued pension and other post-retirement benefit costs	11	5	(13)
Contributions to qualified pension plans	(53)	(20)
Payments for asset retirement obligations	(22)	(35)	(56)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(33)	7	5
Receivables	26	(100)	(38)
Receivables from affiliated companies	17	(26)
Inventory	42	58	66
Other current assets	156	59	(138)
Increase (decrease) in
Accounts payable	(36)	(1)	(32)
Accounts payable to affiliated companies	40	17	(51)
Taxes accrued	(31)	40	1
Other current liabilities	(36)	82	(37)
Other assets	(135)	(428)	(229)
Other liabilities	(167)	(61)	(82)
Net cash provided by (used in) operating activities	1,478	1,109	1,015
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,844)	(1,634)	(1,437)
Purchases of debt and equity securities	(669)	(517)	(557)
Proceeds from sales and maturities of debt and equity securities	695	563	617
Notes receivable from affiliated companies	(173)	313	(313)
Other	(67)	(65)	(7)
Net cash used in investing activities	(2,058)	(1,340)	(1,697)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	918	988	1,306
Payments for the redemption of long-term debt	(262)	(769)	(342)
Notes payable to affiliated companies	(108)	108	(297)
Distributions to parent		(75)
Other	13	1	(1)
Net cash provided by financing activities	561	253	666
Net (decrease) increase in cash, cash equivalents, and restricted cash	(19)	22	(16)
Cash, cash equivalents, and restricted cash at beginning of period	75	53	69
Cash, cash equivalents, and restricted cash at end of period	56	75	53
Cash and cash equivalents at beginning of period	36
Cash and cash equivalents at end of period	17	36
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	332	270	274
Cash (received from) paid for income taxes	1	(120)	(197)
Significant non-cash transactions:
Accrued capital expenditures	272	258	199
Duke Energy Ohio
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net Income Attributable to Parent	238	176	192
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	269	271	265
Equity component of AFUDC	(13)	(11)	(11)
Losses (Gains) on sales of other assets		106	(1)
Impairment charges			1
Deferred income taxes	81	25	90
Accrued pension and other post-retirement benefit costs	2	3	2
Contributions to qualified pension plans	(2)		(4)
Payments for asset retirement obligations	(8)	(3)	(7)
Provision for rate refunds	7	24
(Increase) decrease in
Receivables	20	(33)	2
Receivables from affiliated companies	22	19	(4)
Inventory	(9)	7	6
Other current assets	(5)	16	(22)
Increase (decrease) in
Accounts payable	(17)	(19)	12
Accounts payable to affiliated companies	(10)	16	(1)
Taxes accrued	17	12	11
Other current liabilities	1	14	(19)
Other assets	(22)	(26)	(28)
Other liabilities	(45)	(27)	(5)
Net cash provided by (used in) operating activities	526	570	479
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(952)	(827)	(686)
Notes receivable from affiliated companies		14	80
Other	(68)	(89)	(41)
Net cash used in investing activities	(1,020)	(902)	(647)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	1,003	99	182
Payments for the redemption of long-term debt	(551)	(3)	(2)
Notes payable to affiliated companies	38	245	13
Dividends to parent			(25)
Other			(1)
Net cash provided by financing activities	490	341	167
Net (decrease) increase in cash and cash equivalents	(4)	9	(1)
Cash and cash equivalents at beginning of period	21	12	13
Cash and cash equivalents at end of period	17	21	12
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	97	87	85
Cash (received from) paid for income taxes	(37)	(6)	(8)
Significant non-cash transactions:
Accrued capital expenditures	109	95	82
Transfer of ownership interest of certain equity method investees to parent		106
Duke Energy Indiana
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net Income Attributable to Parent	436	393	354
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	531	524	462
Equity component of AFUDC	(18)	(32)	(28)
Impairment charges		30	18
Deferred income taxes	156	95	152
Accrued pension and other post-retirement benefit costs	6	7	2
Contributions to qualified pension plans	(2)	(8)
Payments for asset retirement obligations	(48)	(69)	(45)
Provision for rate refunds		53
(Increase) decrease in
Receivables	(8)	7	59
Receivables from affiliated companies	41	3	(11)
Inventory	(95)	28	54
Other current assets	76	(25)	28
Increase (decrease) in
Accounts payable	(10)	37	(86)
Accounts payable to affiliated companies	4	5	4
Taxes accrued	(25)	(52)	64
Other current liabilities	15	14	(10)
Other assets	(71)	29	(28)
Other liabilities	9	(33)	(20)
Net cash provided by (used in) operating activities	997	1,006	969
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(876)	(832)	(840)
Purchases of debt and equity securities	(26)	(48)	(20)
Proceeds from sales and maturities of debt and equity securities	20	44	7
Notes receivable from affiliated companies			86
Other	(49)	18	(65)
Net cash used in investing activities	(931)	(818)	(832)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	485
Payments for the redemption of long-term debt	(213)	(3)	(5)
Notes payable to affiliated companies	(137)	6	161
Distributions to parent	(200)	(175)	(300)
Other		(1)	(1)
Net cash provided by financing activities	(65)	(173)	(145)
Net (decrease) increase in cash and cash equivalents	1	15	(8)
Cash and cash equivalents at beginning of period	24	9	17
Cash and cash equivalents at end of period	25	24	9
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	150	162	179
Cash (received from) paid for income taxes	(6)	75	117
Significant non-cash transactions:
Accrued capital expenditures	102	88	125
Piedmont
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net Income Attributable to Parent	202	129	139
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	174	161	151
Impairment charges			7
Deferred income taxes	136	(31)	154
Equity in earnings of unconsolidated affiliates	(8)	(7)	6
Accrued pension and other post-retirement benefit costs	(9)	(4)	23
Contributions to qualified pension plans	(1)		(11)
Provision for rate refunds	2	43
(Increase) decrease in
Receivables	28	7	(40)
Receivables from affiliated companies	12	(15)
Inventory	(2)	(4)
Other current assets	(25)	71	(20)
Increase (decrease) in
Accounts payable	(7)	15	(13)
Accounts payable to affiliated companies	(35)	25	5
Taxes accrued	(60)	65	(48)
Other current liabilities	1	21	(9)
Other assets	9	6	7
Other liabilities	(8)	(4)	(2)
Net cash provided by (used in) operating activities	409	478	349
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,053)	(721)	(585)
Contributions to equity method investments	(16)		(12)
Return of investment capital	4	3	2
Other	(14)	(10)	(6)
Net cash used in investing activities	(1,083)	(731)	(603)
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	596	100	250
Payments for the redemption of long-term debt	(350)		(35)
Notes payable and commercial paper			(330)
Notes payable to affiliated companies	278	(166)	364
Contribution from parent	150	300
Other			(1)
Net cash provided by financing activities	674	234	248
Net (decrease) increase in cash and cash equivalents		(19)	(6)
Cash and cash equivalents at beginning of period		19	25
Cash and cash equivalents at end of period			19
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	84	79	78
Cash (received from) paid for income taxes	(31)	(16)	(12)
Significant non-cash transactions:
Accrued capital expenditures	$ 109	$ 96	34
Transfer of ownership interest of certain equity method investees to parent			$ 149