Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,082	$ 3,571	$ 2,644
Net (loss) income attributable to Duke Energy	1,377	3,748	2,666
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	5,486	5,176	4,696
Equity in losses (earnings) of unconsolidated affiliates	2,005	(162)	(83)
Equity component of AFUDC	(154)	(139)	(221)
(Gains) Losses on sales of other assets	10	(4)	(88)
Impairment charges	984	(8)	402
Deferred income taxes	54	806	1,079
Payments for asset retirement obligations	(610)	(746)	(533)
Payment for the disposal of other assets			(105)
Provision for rate refunds	(22)	60	425
Refund of AMT credit carryforwards	572	573
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	63	(48)	22
Receivables	(56)	78	(345)
Inventory	66	(122)	156
Other current assets	205	10	(721)
Increase (decrease) in
Accounts payable	(21)	(164)	479
Taxes accrued	117	(224)	23
Other current liabilities	(65)	172	270
Other assets	(398)	(559)	(1,062)
Other liabilities	(442)	(69)	(28)
Net cash provided by (used in) operating activities	8,856	8,209	7,186
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(9,907)	(11,122)	(9,389)
Contributions to equity method investments	(370)	(324)	(416)
Return of investment capital	133	11	137
Purchases of debt and equity securities	(8,011)	(3,348)	(3,762)
Proceeds from sales and maturities of debt and equity securities	7,949	3,343	3,747
Other	(398)	(517)	(377)
Net cash used in investing activities	(10,604)	(11,957)	(10,060)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	6,330	7,091	5,299
Net proceeds from Issuance of Preferred Stock and Preference Stock		1,962
Proceeds from Issuance of Common Stock	2,745	384	1,838
Payments for the redemption of long-term debt	(4,506)	(3,476)	(2,906)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	3,009	397	472
Payments for the redemption of short-term debt with original maturities greater than 90 days	(2,147)	(479)	(282)
Notes payable and commercial paper	(1,181)	(298)	981
Contributions from noncontrolling interests	426	843	41
Dividends paid	(2,812)	(2,668)	(2,471)
Other	(133)	(26)	(12)
Net cash provided by financing activities	1,731	3,730	2,960
Net (decrease) increase in cash, cash equivalents, and restricted cash	(17)	(18)	86
Cash, cash equivalents, and restricted cash at beginning of period	573	591	505
Cash, cash equivalents, and restricted cash at end of period	556	573	591
Cash and cash equivalents at beginning of period	311
Cash and cash equivalents at end of period	259	311
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	2,186	2,195	2,086
Cash received from income taxes	(585)	(651)	(266)
Significant non-cash transactions:
Accrued capital expenditures	1,116	1,356	1,112
Non-cash dividends	110	108	107
Duke Energy Carolinas
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income attributable to Duke Energy	956	1,403	1,071
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,731	1,671	1,487
Equity component of AFUDC	(62)	(42)	(73)
(Gains) Losses on sales of other assets	1		(1)
Impairment charges	476	17	192
Deferred income taxes	(260)	133	305
Payments for asset retirement obligations	(162)	(278)	(230)
Provision for rate refunds	(5)	36	182
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(4)	(8)	2
Receivables	52	(21)	(86)
Receivables from affiliated companies	(10)	68	(87)
Inventory	(14)	(48)	25
Other current assets	209	(73)	(161)
Increase (decrease) in
Accounts payable	55	(50)	168
Accounts payable to affiliated companies	(11)	(20)	21
Taxes accrued	30	(127)	(65)
Other current liabilities	(56)	127	89
Other assets	(101)	(42)	(221)
Other liabilities	(47)	(37)	(90)
Net cash provided by (used in) operating activities	2,776	2,709	2,530
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,669)	(2,714)	(2,706)
Purchases of debt and equity securities	(1,602)	(1,658)	(1,810)
Proceeds from sales and maturities of debt and equity securities	1,602	1,658	1,810
Other	(164)	(204)	(147)
Net cash used in investing activities	(2,833)	(2,918)	(2,853)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	998	886	1,983
Payments for the redemption of long-term debt	(813)	(6)	(1,205)
Notes payable to affiliated companies	477	(410)	335
Distributions to parent	(600)	(275)	(750)
Other	(2)	(1)	(23)
Net cash provided by financing activities	60	194	340
Net increase (decrease) in cash and cash equivalents	3	(15)	17
Cash and cash equivalents at beginning of period	18	33	16
Cash and cash equivalents at end of period	21	18	33
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	481	433	452
Cash received from income taxes	321	122	89
Significant non-cash transactions:
Accrued capital expenditures	365	347	302
Progress Energy
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	1,046	1,327	1,033
Net (loss) income attributable to Duke Energy	1,045	1,327	1,027
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	2,327	2,207	1,987
Equity component of AFUDC	(42)	(66)	(104)
(Gains) Losses on sales of other assets	9		24
Impairment charges	495	(24)	87
Deferred income taxes	(197)	433	358
Payments for asset retirement obligations	(384)	(412)	(230)
Provision for rate refunds	2	15	122
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(9)	(34)	18
Receivables	(69)	47	(207)
Receivables from affiliated companies	(81)	81	(137)
Inventory	49	62	121
Other current assets	223	184	(12)
Increase (decrease) in
Accounts payable	(62)	(4)	217
Accounts payable to affiliated companies	(21)	(50)	109
Taxes accrued	75	(74)	8
Other current liabilities	139	25	129
Other assets	(128)	(341)	(896)
Other liabilities	(177)	(167)	(35)
Net cash provided by (used in) operating activities	3,177	3,209	2,544
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(3,488)	(3,952)	(3,854)
Purchases of debt and equity securities	(5,998)	(1,511)	(1,753)
Proceeds from sales and maturities of debt and equity securities	6,010	1,504	1,769
Notes receivable from affiliated companies	164	(164)	240
Other	(160)	(190)	(162)
Net cash used in investing activities	(3,472)	(4,313)	(3,760)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,791	2,187	1,833
Payments for the redemption of long-term debt	(2,157)	(1,667)	(771)
Notes payable to affiliated companies	1,148	586	430
Dividends to parent	(400)		(250)
Other	(13)	12	(1)
Net cash provided by financing activities	369	1,118	1,241
Net (decrease) increase in cash, cash equivalents, and restricted cash	74	14	25
Cash, cash equivalents, and restricted cash at beginning of period	126	112	87
Cash, cash equivalents, and restricted cash at end of period	200	126	112
Cash and cash equivalents at beginning of period	48
Cash and cash equivalents at end of period	59	48
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	819	892	798
Cash received from income taxes	149	(79)	(348)
Significant non-cash transactions:
Accrued capital expenditures	363	447	478
Duke Energy Progress
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income attributable to Duke Energy	415	805	667
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,299	1,329	1,183
Equity component of AFUDC	(29)	(60)	(57)
(Gains) Losses on sales of other assets	8		9
Impairment charges	499	12	33
Deferred income taxes	(234)	197	236
Payments for asset retirement obligations	(304)	(390)	(195)
Provision for rate refunds	2	12	122
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	1	(6)	5
Receivables	(4)	21	(107)
Receivables from affiliated companies	2	(29)	(20)
Inventory	23	20	63
Other current assets	98	101	(201)
Increase (decrease) in
Accounts payable	(127)	32	219
Accounts payable to affiliated companies	12	(75)	99
Taxes accrued	68	(46)	(11)
Other current liabilities	157	68	46
Other assets	(207)	(205)	(465)
Other liabilities	3	37	20
Net cash provided by (used in) operating activities	1,666	1,823	1,628
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,581)	(2,108)	(2,220)
Purchases of debt and equity securities	(1,555)	(842)	(1,236)
Proceeds from sales and maturities of debt and equity securities	1,516	810	1,206
Other	(57)	(119)	(95)
Net cash used in investing activities	(1,677)	(2,259)	(2,345)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,296	1,269	845
Payments for the redemption of long-term debt	(1,085)	(605)	(3)
Notes payable to affiliated companies	229	(228)	54
Distributions to parent	(400)		(175)
Other	(12)	(1)	(1)
Net cash provided by financing activities	28	435	720
Net increase (decrease) in cash and cash equivalents	17	(1)	3
Cash and cash equivalents at beginning of period	22	23	20
Cash and cash equivalents at end of period	39	22	23
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	301	331	303
Cash received from income taxes	123	(30)	(112)
Significant non-cash transactions:
Accrued capital expenditures	149	175	220
Duke Energy Florida
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income attributable to Duke Energy	771	692	554
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,019	869	793
Equity component of AFUDC	(12)	(6)	(47)
(Gains) Losses on sales of other assets	1		1
Impairment charges	(4)	(36)	54
Deferred income taxes	27	180	159
Payments for asset retirement obligations	(80)	(22)	(35)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(14)	(33)	7
Receivables	(64)	26	(100)
Receivables from affiliated companies	(3)	17	(26)
Inventory	26	42	58
Other current assets	40	156	59
Increase (decrease) in
Accounts payable	66	(36)	(1)
Accounts payable to affiliated companies	(46)	40	17
Taxes accrued	39	(31)	40
Other current liabilities	(7)	(36)	82
Other assets	85	(131)	(429)
Other liabilities	(181)	(213)	(75)
Net cash provided by (used in) operating activities	1,661	1,478	1,109
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,907)	(1,844)	(1,634)
Purchases of debt and equity securities	(4,443)	(669)	(517)
Proceeds from sales and maturities of debt and equity securities	4,495	695	563
Notes receivable from affiliated companies	173	(173)	313
Other	(103)	(67)	(65)
Net cash used in investing activities	(1,785)	(2,058)	(1,340)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	495	918	988
Payments for the redemption of long-term debt	(572)	(262)	(769)
Notes payable to affiliated companies	196	(108)	108
Distributions to parent			(75)
Other	(1)	13	1
Net cash provided by financing activities	118	561	253
Net (decrease) increase in cash, cash equivalents, and restricted cash	(6)	(19)	22
Cash, cash equivalents, and restricted cash at beginning of period	56	75	53
Cash, cash equivalents, and restricted cash at end of period	50	56	75
Cash and cash equivalents at beginning of period	17
Cash and cash equivalents at end of period	11	17
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	321	332	270
Cash received from income taxes	138	1	(120)
Significant non-cash transactions:
Accrued capital expenditures	214	272	258
Duke Energy Ohio
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income attributable to Duke Energy	252	238	176
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	283	269	271
Equity component of AFUDC	(7)	(13)	(11)
(Gains) Losses on sales of other assets	0	0	(106)
Deferred income taxes	31	81	25
Payments for asset retirement obligations	(2)	(8)	(3)
Provision for rate refunds	14	7	24
(Increase) decrease in
Receivables	(13)	20	(33)
Receivables from affiliated companies	9	22	19
Inventory	25	(9)	7
Other current assets	(18)	(5)	16
Increase (decrease) in
Accounts payable	2	(17)	(19)
Accounts payable to affiliated companies	0	(10)	16
Taxes accrued	30	17	12
Other current liabilities	3	1	14
Other assets	(32)	(26)	(24)
Other liabilities	(2)	(41)	(26)
Net cash provided by (used in) operating activities	575	526	570
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(834)	(952)	(827)
Notes receivable from affiliated companies	(19)		14
Other	(48)	(68)	(89)
Net cash used in investing activities	(901)	(1,020)	(902)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	467	1,003	99
Payments for the redemption of long-term debt		(551)	(3)
Notes payable to affiliated companies	(144)	38	245
Net cash provided by financing activities	323	490	341
Net increase (decrease) in cash and cash equivalents	(3)	(4)	9
Cash and cash equivalents at beginning of period	17	21	12
Cash and cash equivalents at end of period	14	17	21
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	97	97	87
Cash received from income taxes		(37)	(6)
Significant non-cash transactions:
Accrued capital expenditures	104	109	95
Transfer of ownership interest of certain equity method investees to parent			106
Duke Energy Indiana
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income attributable to Duke Energy	408	436	393
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	572	531	524
Equity component of AFUDC	(23)	(18)	(32)
Impairment charges			30
Deferred income taxes	29	156	95
Payments for asset retirement obligations	(63)	(48)	(69)
Provision for rate refunds			53
(Increase) decrease in
Receivables	8	(8)	7
Receivables from affiliated companies	0	41	3
Inventory	44	(95)	28
Other current assets	(3)	76	(25)
Increase (decrease) in
Accounts payable	(12)	(10)	37
Accounts payable to affiliated companies	1	4	5
Taxes accrued	13	(25)	(52)
Other current liabilities	6	15	14
Other assets	(68)	(74)	26
Other liabilities	26	16	(31)
Net cash provided by (used in) operating activities	938	997	1,006
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(888)	(876)	(832)
Purchases of debt and equity securities	(37)	(26)	(48)
Proceeds from sales and maturities of debt and equity securities	22	20	44
Notes receivable from affiliated companies	(33)
Other	48	(49)	18
Net cash used in investing activities	(888)	(931)	(818)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	544	485
Payments for the redemption of long-term debt	(513)	(213)	(3)
Notes payable to affiliated companies	101	(137)	6
Distributions to parent	(200)	(200)	(175)
Other			(1)
Net cash provided by financing activities	(68)	(65)	(173)
Net increase (decrease) in cash and cash equivalents	(18)	1	15
Cash and cash equivalents at beginning of period	25	24	9
Cash and cash equivalents at end of period	7	25	24
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	164	150	162
Cash received from income taxes	36	(6)	75
Significant non-cash transactions:
Accrued capital expenditures	101	102	88
Piedmont
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income attributable to Duke Energy	273	202	129
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	182	174	161
Equity in losses (earnings) of unconsolidated affiliates	(9)	(8)	(7)
Equity component of AFUDC	(19)
Impairment charges	7
Deferred income taxes	53	136	(31)
Provision for rate refunds	(33)	2	43
(Increase) decrease in
Receivables	10	28	7
Receivables from affiliated companies		12	(15)
Inventory	3	(2)	(4)
Other current assets	(66)	(25)	71
Increase (decrease) in
Accounts payable	16	(7)	15
Accounts payable to affiliated companies	76	(35)	25
Taxes accrued	3	(60)	65
Other current liabilities	(11)	1	21
Other assets	(11)	1	3
Other liabilities	7	(10)	(5)
Net cash provided by (used in) operating activities	481	409	478
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(901)	(1,053)	(721)
Contributions to equity method investments		(16)
Return of investment capital	2	4	3
Other	(28)	(14)	(10)
Net cash used in investing activities	(929)	(1,083)	(731)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	394	596	100
Payments for the redemption of long-term debt		(350)
Notes payable to affiliated companies	54	278	(166)
Contribution from parent		150	300
Net cash provided by financing activities	448	674	234
Net increase (decrease) in cash and cash equivalents			(19)
Cash and cash equivalents at beginning of period			19
Supplemental Disclosures:
Cash paid for interest, net of amount capitalized	115	84	79
Cash received from income taxes	(36)	(31)	(16)
Significant non-cash transactions:
Accrued capital expenditures	$ 106	$ 109	$ 96