Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 893	$ 622
Net income (attributable to parent)	900	620
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,238	1,089
Equity component of AFUDC	(31)	(55)
Losses on sales of other assets	3	100
Impairment charges		43
Deferred income taxes	97	199
Equity in (earnings) losses of unconsolidated affiliates	(43)	24
Accrued pension and other post-retirement benefit costs	2	15
Contributions to qualified pension plans		(141)
Payments for asset retirement obligations	(152)	(122)
Payment for disposal of other assets		(105)
Other rate case adjustments		37
Provision for rate refunds	35	158
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	10	4
Receivables	388	64
Inventory	(31)	101
Other current assets	98	27
Increase (decrease) in
Accounts payable	(636)	(327)
Taxes accrued	(107)	(107)
Other current liabilities	(407)	(171)
Other assets	(158)	(59)
Other liabilities	40	(5)
Net cash provided by operating activities	1,239	1,391
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,536)	(2,087)
Contributions to equity method investments	(94)	(74)
Purchases of debt and equity securities	(860)	(958)
Proceeds from sales and maturities of debt and equity securities	851	930
Other	(74)	(75)
Net cash used in investing activities	(2,713)	(2,264)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	2,737	1,240
Proceeds from the issuance of preferred stock	974
Proceeds from the issuance of common stock	13	21
Payments for the redemption of long-term debt	(1,201)	(487)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	135	135
Payments for the redemption of short-term debt with original maturities greater than 90 days	(239)	(50)
Notes payable and commercial paper	(304)	706
Dividends paid	(649)	(599)
Other	(33)	(19)
Net cash provided by financing activities	1,433	947
Net (decrease) increase in cash, cash equivalents and restricted cash	(41)	74
Cash, cash equivalents and restricted cash at beginning of period	591	505
Cash, cash equivalents and restricted cash at end of period	550	579
Cash and cash equivalents at beginning of period	442
Cash and cash equivalents at end of period	377
Significant non-cash transactions:
Accrued capital expenditures	811	799
Non-cash dividends	27	26
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	293	323
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	388	347
Equity component of AFUDC	(9)	(21)
Impairment charges		13
Deferred income taxes	64	80
Accrued pension and other post-retirement benefit costs	(2)	1
Contributions to qualified pension plans		(46)
Payments for asset retirement obligations	(65)	(55)
Provision for rate refunds	19	61
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	1
Receivables	124	19
Receivable from affiliated companies	94	(11)
Inventory	(59)	(9)
Other current assets	(35)	(144)
Increase (decrease) in
Accounts payable	(266)	(76)
Accounts payable to affiliated companies	18	50
Taxes accrued	(91)	(129)
Other current liabilities	(70)	(23)
Other assets	(29)	12
Other liabilities	(7)	(43)
Net cash provided by operating activities	368	349
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(721)	(621)
Purchases of debt and equity securities	(405)	(494)
Proceeds from sales and maturities of debt and equity securities	405	494
Other	(9)	(21)
Net cash used in investing activities	(730)	(642)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	25	991
Payments for the redemption of long-term debt	(1)	(401)
Notes payable to affiliated companies	306	(59)
Distributions to parent		(250)
Other	(1)	(1)
Net cash provided by financing activities	329	280
Net increase (decrease) in cash and cash equivalents	(33)	(13)
Cash and cash equivalents at beginning of period	33	16
Cash and cash equivalents at end of period		3
Significant non-cash transactions:
Accrued capital expenditures	221	267
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	248	237
Net income (attributable to parent)	249	235
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	546	439
Equity component of AFUDC	(15)	(26)
Losses on sales of other assets		(6)
Impairment charges		29
Deferred income taxes	82	71
Accrued pension and other post-retirement benefit costs	4	6
Contributions to qualified pension plans		(45)
Payments for asset retirement obligations	(75)	(55)
Other rate case adjustments		37
Provision for rate refunds	6	33
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	1	4
Receivables	187	(33)
Receivable from affiliated companies	122	29
Inventory	(18)	55
Other current assets	35	(60)
Increase (decrease) in
Accounts payable	(196)	(53)
Accounts payable to affiliated companies	(94)	33
Taxes accrued	26	8
Other current liabilities	(196)	(82)
Other assets	(112)	(86)
Other liabilities	(10)	(8)
Net cash provided by operating activities	541	527
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,012)	(762)
Purchases of debt and equity securities	(409)	(406)
Proceeds from sales and maturities of debt and equity securities	405	411
Notes receivable from affiliated companies	(31)	127
Other	(45)	(40)
Net cash used in investing activities	(1,092)	(670)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,295
Payments for the redemption of long-term debt	(1,132)	(80)
Notes payable to affiliated companies	370	177
Other	1	(2)
Net cash provided by financing activities	534	95
Net (decrease) increase in cash, cash equivalents and restricted cash	(17)	(48)
Cash, cash equivalents and restricted cash at beginning of period	112	87
Cash, cash equivalents and restricted cash at end of period	95	39
Cash and cash equivalents at beginning of period	67
Cash and cash equivalents at end of period	45
Significant non-cash transactions:
Accrued capital expenditures	310	316
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	203	177
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	336	284
Equity component of AFUDC	(14)	(14)
Losses on sales of other assets		(1)
Impairment charges		32
Deferred income taxes	33	42
Accrued pension and other post-retirement benefit costs		4
Contributions to qualified pension plans		(25)
Payments for asset retirement obligations	(68)	(44)
Other rate case adjustments		37
Provision for rate refunds	6	33
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(3)	2
Receivables	87	(31)
Receivable from affiliated companies	(5)	(2)
Inventory	(5)	15
Other current assets	96	(88)
Increase (decrease) in
Accounts payable	(196)	(39)
Accounts payable to affiliated companies	(57)	29
Taxes accrued	(4)	(28)
Other current liabilities	(109)	(64)
Other assets	(45)	18
Other liabilities	(9)	(5)
Net cash provided by operating activities	246	332
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(548)	(424)
Purchases of debt and equity securities	(315)	(284)
Proceeds from sales and maturities of debt and equity securities	308	281
Notes receivable from affiliated companies	(38)
Other	(20)	(30)
Net cash used in investing activities	(613)	(457)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,270
Payments for the redemption of long-term debt	(601)
Notes payable to affiliated companies	(294)	114
Other	(1)	(1)
Net cash provided by financing activities	374	113
Net increase (decrease) in cash and cash equivalents	7	(12)
Cash and cash equivalents at beginning of period	23	20
Cash and cash equivalents at end of period	30	8
Significant non-cash transactions:
Accrued capital expenditures	117	137
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	96	103
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	207	152
Equity component of AFUDC	(1)	(12)
Deferred income taxes	45	29
Accrued pension and other post-retirement benefit costs	3	1
Contributions to qualified pension plans		(20)
Payments for asset retirement obligations	(7)	(11)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2	2
Receivables	55	(2)
Receivable from affiliated companies	(6)
Inventory	(13)	39
Other current assets	(35)	42
Increase (decrease) in
Accounts payable		(13)
Accounts payable to affiliated companies	(62)	8
Taxes accrued	20	38
Other current liabilities	(84)	(17)
Other assets	(66)	(107)
Other liabilities	(1)	(5)
Net cash provided by operating activities	153	227
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(422)	(338)
Purchases of debt and equity securities	(95)	(122)
Proceeds from sales and maturities of debt and equity securities	97	129
Notes receivable from affiliated companies		160
Other	(25)	(10)
Net cash used in investing activities	(445)	(181)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	25
Payments for the redemption of long-term debt	(81)	(80)
Notes payable to affiliated companies	291
Other	2
Net cash provided by financing activities	237	(80)
Net (decrease) increase in cash, cash equivalents and restricted cash	(55)	(34)
Cash, cash equivalents and restricted cash at beginning of period	75	53
Cash, cash equivalents and restricted cash at end of period	20	19
Cash and cash equivalents at beginning of period	36
Cash and cash equivalents at end of period	8
Significant non-cash transactions:
Accrued capital expenditures	193	179
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	69	(25)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	65	71
Equity component of AFUDC	(3)	(4)
Losses on sales of other assets		106
Deferred income taxes	20	(15)
Accrued pension and other post-retirement benefit costs		1
Payments for asset retirement obligations	(1)	(1)
Provision for rate refunds	4	16
(Increase) decrease in
Receivables	5	(1)
Receivable from affiliated companies	35	56
Inventory	15	25
Other current assets	(6)	19
Increase (decrease) in
Accounts payable	(5)	(27)
Accounts payable to affiliated companies	(8)	(95)
Taxes accrued	(45)	(45)
Other current liabilities	14	20
Other assets	(10)
Other liabilities	(4)	(13)
Net cash provided by operating activities	145	88
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(233)	(188)
Notes receivable from affiliated companies	(463)	14
Other	(11)	(14)
Net cash used in investing activities	(707)	(188)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	794
Notes payable to affiliated companies	(236)	101
Other		(1)
Net cash provided by financing activities	558	100
Net increase (decrease) in cash and cash equivalents	(4)
Cash and cash equivalents at beginning of period	21	12
Cash and cash equivalents at end of period	17	12
Significant non-cash transactions:
Accrued capital expenditures	68	64
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	110	100
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	132	131
Equity component of AFUDC	(4)	(4)
Losses on sales of other assets	3
Deferred income taxes	28	17
Accrued pension and other post-retirement benefit costs	1	2
Contributions to qualified pension plans		(8)
Payments for asset retirement obligations	(11)	(11)
Provision for rate refunds		26
(Increase) decrease in
Receivables	4
Receivable from affiliated companies	20	26
Inventory	(13)	(3)
Other current assets	19	(23)
Increase (decrease) in
Accounts payable	8	21
Accounts payable to affiliated companies	(11)	(5)
Taxes accrued	20	(1)
Other current liabilities	(15)	(10)
Other assets	12	(1)
Other liabilities	5
Net cash provided by operating activities	308	257
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(208)	(231)
Purchases of debt and equity securities	(6)	(6)
Proceeds from sales and maturities of debt and equity securities	4	3
Other	(11)	(4)
Net cash used in investing activities	(221)	(238)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	(60)	(12)
Notes payable to affiliated companies	(31)
Other		(1)
Net cash provided by financing activities	(91)	(13)
Net increase (decrease) in cash and cash equivalents	(4)	6
Cash and cash equivalents at beginning of period	24	9
Cash and cash equivalents at end of period	20	15
Significant non-cash transactions:
Accrued capital expenditures	76	64
Piedmont Natural Gas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	122	110
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	42	39
Deferred income taxes	23	(7)
Equity in (earnings) losses of unconsolidated affiliates	(2)	(2)
Accrued pension and other post-retirement benefit costs	(2)	(1)
Provision for rate refunds	7	23
(Increase) decrease in
Receivables	27	22
Receivable from affiliated companies	12
Inventory	45	37
Other current assets	22	79
Increase (decrease) in
Accounts payable	(44)	(15)
Accounts payable to affiliated companies	(4)	19
Taxes accrued	(49)	46
Other current liabilities	15	18
Other assets	(1)	4
Other liabilities	(5)	(1)
Net cash provided by operating activities	208	371
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(209)	(121)
Other	(2)
Net cash used in investing activities	(211)	(121)
CASH FLOWS FROM FINANCING ACTIVITIES
Notes payable to affiliated companies	3	(257)
Net cash provided by financing activities	3	(257)
Net increase (decrease) in cash and cash equivalents		(7)
Cash and cash equivalents at beginning of period		19
Cash and cash equivalents at end of period		12
Significant non-cash transactions:
Accrued capital expenditures	$ 92	$ 52