Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,124	$ 1,406
Net income (attributable to parent)	1,120	1,402
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	2,250	1,953
Equity component of AFUDC	(106)	(125)
Losses (gains) on sales of other assets	97	(20)
Impairment charges	215	9
Deferred income taxes	289	669
Equity in earnings of unconsolidated affiliates	(12)	(65)
Accrued pension and other post-retirement benefit costs	31	13
Contributions to qualified pension plans	(141)
Payments for asset retirement obligations	(245)	(272)
Payment for disposal of other assets	(105)
Other rate case adjustments	37
Provision for rate refunds	281
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	7	(12)
Receivables	(27)	293
Inventory	70	153
Other current assets	21	(168)
Increase (decrease) in
Accounts payable	(142)	(505)
Taxes accrued	(58)	41
Other current liabilities	(214)	(531)
Other assets	(112)	(37)
Other liabilities	42	(2)
Net cash provided by operating activities	3,302	2,800
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(4,375)	(3,931)
Contributions to equity method investments	(140)	(287)
Purchases of debt and equity securities	(1,908)	(2,412)
Proceeds from sales and maturities of debt and equity securities	1,866	2,439
Other	(88)	(153)
Net cash used in investing activities	(4,645)	(4,344)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	2,727	2,734
Proceeds from the issuance of common stock	820
Payments for the redemption of long-term debt	(2,190)	(1,009)
Proceeds from issuance of short-term debt with original maturities greater than 90 days	201	230
Payments for the redemption of short-term debt with original maturities greater than 90 days	(160)	(32)
Notes payable and commercial paper	1,090	783
Dividends paid	(1,199)	(1,200)
Other	(24)	(32)
Net cash provided by financing activities	1,265	1,474
Net decrease in cash, cash equivalents and restricted cash	(78)	(70)
Cash, cash equivalents and restricted cash at beginning of period	505	541
Cash, cash equivalents and restricted cash at end of period	427	471
Cash and cash equivalents at beginning of period	358
Cash and cash equivalents at end of period	304
Significant non-cash transactions:
Accrued capital expenditures	978	589
Non-cash dividends	52
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	440	543
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	707	688
Equity component of AFUDC	(39)	(59)
Losses (gains) on sales of other assets	1
Impairment charges	190
Deferred income taxes	90	283
Accrued pension and other post-retirement benefit costs	2
Contributions to qualified pension plans	(46)
Payments for asset retirement obligations	(114)	(123)
Provision for rate refunds	121
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	8	24
Receivables	(33)	36
Receivable from affiliated companies	(22)	78
Inventory	(16)	(14)
Other current assets	(33)	(21)
Increase (decrease) in
Accounts payable	(59)	(125)
Accounts payable to affiliated companies	(51)	(120)
Taxes accrued	(78)	19
Other current liabilities	(123)	(140)
Other assets	(6)	(44)
Other liabilities	(29)	(15)
Net cash provided by operating activities	910	1,010
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,270)	(1,092)
Purchases of debt and equity securities	(976)	(1,225)
Proceeds from sales and maturities of debt and equity securities	976	1,228
Notes receivable from affiliated companies		66
Other	(64)	(29)
Net cash used in investing activities	(1,334)	(1,052)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	991
Payments for the redemption of long-term debt	(702)	(114)
Notes payable to affiliated companies	636	534
Distributions to parent	(500)	(375)
Other	(1)	(1)
Net cash provided by financing activities	424	44
Net increase (decrease) in cash and cash equivalents		2
Cash and cash equivalents at beginning of period	16	14
Cash and cash equivalents at end of period	16	16
Significant non-cash transactions:
Accrued capital expenditures	343	200
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	504	478
Net income (attributable to parent)	500	473
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	945	733
Equity component of AFUDC	(52)	(48)
Losses (gains) on sales of other assets	(12)	(15)
Impairment charges	33	2
Deferred income taxes	240	412
Accrued pension and other post-retirement benefit costs	12	(5)
Contributions to qualified pension plans	(45)
Payments for asset retirement obligations	(108)	(128)
Other rate case adjustments	37
Provision for rate refunds	65
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	14
Receivables	(196)	(64)
Receivable from affiliated companies	28	99
Inventory	71	95
Other current assets	(214)	(220)
Increase (decrease) in
Accounts payable	15	(211)
Accounts payable to affiliated companies	(19)	(140)
Taxes accrued	80	81
Other current liabilities	(58)	(148)
Other assets	(186)	(69)
Other liabilities	4	(18)
Net cash provided by operating activities	1,158	834
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,727)	(1,733)
Purchases of debt and equity securities	(812)	(1,108)
Proceeds from sales and maturities of debt and equity securities	820	1,123
Notes receivable from affiliated companies	(69)	(60)
Other	(81)	(22)
Net cash used in investing activities	(1,869)	(1,800)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	989	923
Payments for the redemption of long-term debt	(635)	(326)
Notes payable to affiliated companies	347	341
Other	(3)	(3)
Net cash provided by financing activities	698	935
Net decrease in cash, cash equivalents and restricted cash	(13)	(31)
Cash, cash equivalents and restricted cash at beginning of period	87	110
Cash, cash equivalents and restricted cash at end of period	74	79
Cash and cash equivalents at beginning of period	40
Cash and cash equivalents at end of period	37
Significant non-cash transactions:
Accrued capital expenditures	366	174
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	316	301
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	565	453
Equity component of AFUDC	(26)	(26)
Losses (gains) on sales of other assets	(2)	(4)
Impairment charges	33
Deferred income taxes	53	224
Accrued pension and other post-retirement benefit costs	7	(10)
Contributions to qualified pension plans	(25)
Payments for asset retirement obligations	(89)	(101)
Other rate case adjustments	37
Provision for rate refunds	65
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	6	(3)
Receivables	(104)	3
Receivable from affiliated companies	2
Inventory	41	23
Other current assets	(111)	(50)
Increase (decrease) in
Accounts payable	(17)	(218)
Accounts payable to affiliated companies	(4)	(58)
Taxes accrued	26	(43)
Other current liabilities	(38)	(111)
Other assets	10	(37)
Other liabilities	13	(9)
Net cash provided by operating activities	758	334
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(996)	(840)
Purchases of debt and equity securities	(573)	(819)
Proceeds from sales and maturities of debt and equity securities	556	805
Notes receivable from affiliated companies		165
Other	(45)	(22)
Net cash used in investing activities	(1,058)	(711)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		15
Payments for the redemption of long-term debt		(269)
Notes payable to affiliated companies	300	633
Other	(2)	(1)
Net cash provided by financing activities	298	378
Net increase (decrease) in cash and cash equivalents	(2)	1
Cash and cash equivalents at beginning of period	20	11
Cash and cash equivalents at end of period	18	12
Significant non-cash transactions:
Accrued capital expenditures	172	52
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	271	248
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	374	274
Equity component of AFUDC	(26)	(22)
Impairment charges		2
Deferred income taxes	206	186
Accrued pension and other post-retirement benefit costs	3	2
Contributions to qualified pension plans	(20)
Payments for asset retirement obligations	(19)	(27)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	6	2
Receivables	(92)	(65)
Receivable from affiliated companies	(4)
Inventory	28	72
Other current assets	(114)	(67)
Increase (decrease) in
Accounts payable	34	7
Accounts payable to affiliated companies	(11)	(83)
Taxes accrued	81	78
Other current liabilities	(21)	(57)
Other assets	(196)	(32)
Other liabilities	(10)	(5)
Net cash provided by operating activities	490	513
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(731)	(893)
Purchases of debt and equity securities	(239)	(289)
Proceeds from sales and maturities of debt and equity securities	264	318
Notes receivable from affiliated companies	(110)	(230)
Other	(35)
Net cash used in investing activities	(851)	(1,094)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	989	908
Payments for the redemption of long-term debt	(635)	(57)
Notes payable to affiliated companies		(297)
Other	(1)	(1)
Net cash provided by financing activities	353	553
Net decrease in cash, cash equivalents and restricted cash	(8)	(28)
Cash, cash equivalents and restricted cash at beginning of period	53	69
Cash, cash equivalents and restricted cash at end of period	45	41
Cash and cash equivalents at beginning of period	13
Cash and cash equivalents at end of period	14
Significant non-cash transactions:
Accrued capital expenditures	194	122
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	21	72
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	134	132
Equity component of AFUDC	(8)	(5)
Losses (gains) on sales of other assets	106
Impairment charges		1
Deferred income taxes	(2)	64
Accrued pension and other post-retirement benefit costs	2	2
Payments for asset retirement obligations	(2)	(3)
Provision for rate refunds	19
(Increase) decrease in
Receivables	(7)	11
Receivable from affiliated companies	62	55
Inventory	9	6
Other current assets	24	(11)
Increase (decrease) in
Accounts payable	(34)	(4)
Accounts payable to affiliated companies	(15)	(16)
Taxes accrued	(63)	(79)
Other current liabilities	8	(15)
Other assets	(7)	(12)
Other liabilities	(18)	(8)
Net cash provided by operating activities	229	190
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(392)	(286)
Cost of removal, net of salvage	(43)	(13)
Notes receivable from affiliated companies	14	31
Net cash used in investing activities	(421)	(268)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		93
Payments for the redemption of long-term debt	(3)	(1)
Notes payable to affiliated companies	190	8
Dividends to parent		(25)
Other		(1)
Net cash provided by financing activities	187	74
Net increase (decrease) in cash and cash equivalents	(5)	(4)
Cash and cash equivalents at beginning of period	12	13
Cash and cash equivalents at end of period	7	9
Significant non-cash transactions:
Accrued capital expenditures	70	59
Non-cash equity contribution from parent or Transfer of ownership interest of certain equity method investees to parent	106
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	198	197
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	258	218
Equity component of AFUDC	(7)	(12)
Deferred income taxes	36	131
Accrued pension and other post-retirement benefit costs	3	3
Contributions to qualified pension plans	(8)
Payments for asset retirement obligations	(21)	(17)
Provision for rate refunds	49
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		1
Receivables	2	73
Receivable from affiliated companies	36	27
Inventory	(20)	34
Other current assets	(35)	(15)
Increase (decrease) in
Accounts payable	33	(68)
Accounts payable to affiliated companies	(19)	(24)
Taxes accrued	(41)	(3)
Other current liabilities	3	(11)
Other assets	20	(13)
Other liabilities	(21)	(9)
Net cash provided by operating activities	466	512
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(416)	(397)
Purchases of debt and equity securities	(34)	(10)
Proceeds from sales and maturities of debt and equity securities	13	4
Notes receivable from affiliated companies		67
Other	2	(23)
Net cash used in investing activities	(435)	(359)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt		(2)
Notes payable to affiliated companies	60
Distributions to parent	(75)	(150)
Other	(1)	(1)
Net cash provided by financing activities	(16)	(153)
Net increase (decrease) in cash and cash equivalents	15
Cash and cash equivalents at beginning of period	9	17
Cash and cash equivalents at end of period	24	17
Significant non-cash transactions:
Accrued capital expenditures	62	81
Piedmont Natural Gas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	102	87
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	79	74
Impairment charges		7
Deferred income taxes	4	100
Equity in earnings of unconsolidated affiliates	(3)	(5)
Accrued pension and other post-retirement benefit costs	(2)	6
Provision for rate refunds	27
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		(39)
Receivables	166	155
Receivable from affiliated companies	(4)	(1)
Inventory	28	28
Other current assets	74	(64)
Increase (decrease) in
Accounts payable	(32)	(44)
Accounts payable to affiliated companies	(12)	42
Taxes accrued	4	(46)
Other current liabilities	28	(23)
Other assets	2	28
Other liabilities	(2)	(6)
Net cash provided by operating activities	459	299
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(327)	(260)
Contributions to equity method investments		(12)
Notes receivable from affiliated companies	(77)
Other	(2)	1
Net cash used in investing activities	(406)	(271)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		125
Notes payable and commercial paper		(330)
Notes payable to affiliated companies	(364)	167
Capital contributions from parent	300
Other		(1)
Net cash provided by financing activities	(64)	(39)
Net increase (decrease) in cash and cash equivalents	(11)	(11)
Cash and cash equivalents at beginning of period	19	25
Cash and cash equivalents at end of period	8	14
Significant non-cash transactions:
Accrued capital expenditures	$ 73	45
Non-cash equity contribution from parent or Transfer of ownership interest of certain equity method investees to parent		$ 149