Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Allowance for doubtful accounts - receivables	$ 16	$ 16
Regulatory assets, current	1,918	2,005
Other, current assets	1,267	1,049
Regulatory assets, noncurrent	13,393	13,617
Other, noncurrent assets	2,975	2,935
Current maturities of long-term debt	2,698	3,406
Long-Term Debt	$ 54,342	$ 51,123
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	728,000,000	727,000,000
Preferred stock, par value (in usd per share)	$ 0.001
Preferred stock, depositary shares authorized	40,000,000
Preferred stock, depositary shares outstanding	40,000,000
Other	$ 1,583	$ 1,650
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	55	55
Regulatory assets, current	52	52
Other, current assets	140	162
Regulatory assets, noncurrent	1,019	1,041
Other, noncurrent assets	289	261
Current maturities of long-term debt	232	227
Long-Term Debt	4,070	3,998
Other	222	212
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	605	520
Other, current assets	17	72
Regulatory assets, noncurrent	3,392	3,457
Other, noncurrent assets	1,085	1,027
Current maturities of long-term debt	456	6
Long-Term Debt	10,208	10,633
Other	645	671
Duke Energy Carolinas [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	7	7
Progress Energy [Member]
Allowance for doubtful accounts - receivables	6	5
Regulatory assets, current	1,024	1,137
Other, current assets	107	125
Regulatory assets, noncurrent	6,423	6,564
Other, noncurrent assets	982	974
Current maturities of long-term debt	1,026	1,672
Long-Term Debt	$ 18,023	$ 17,089
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Other	$ 352	$ 351
Progress Energy [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	8	8
Regulatory assets, current	52	52
Other, current assets	31	39
Regulatory assets, noncurrent	1,019	1,041
Current maturities of long-term debt	54	53
Long-Term Debt	1,657	1,636
Duke Energy Progress [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	572	703
Other, current assets	34	62
Regulatory assets, noncurrent	4,124	4,111
Other, noncurrent assets	586	612
Current maturities of long-term debt	6	603
Long-Term Debt	8,893	7,451
Other	91	106
Duke Energy Progress [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	5	5
Duke Energy Florida [Member]
Allowance for doubtful accounts - receivables	3	3
Regulatory assets, current	452	434
Other, current assets	46	46
Regulatory assets, noncurrent	2,299	2,454
Other, noncurrent assets	311	311
Current maturities of long-term debt	671	270
Long-Term Debt	6,542	7,051
Other	104	93
Duke Energy Florida [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	3	3
Regulatory assets, current	52	52
Other, current assets	31	39
Regulatory assets, noncurrent	1,019	1,041
Current maturities of long-term debt	54	53
Long-Term Debt	1,332	1,336
Duke Energy Ohio [Member]
Allowance for doubtful accounts - receivables	3	2
Regulatory assets, current	47	33
Other, current assets	32	24
Regulatory assets, noncurrent	545	531
Other, noncurrent assets	46	41
Current maturities of long-term debt	100	551
Long-Term Debt	$ 2,384	$ 1,589
Common stock, par value (in usd per share)	$ 8.50	$ 8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	90,000,000	90,000,000
Other	$ 94	$ 93
Duke Energy Indiana [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	130	175
Other, current assets	42	35
Regulatory assets, noncurrent	1,038	982
Other, noncurrent assets	203	194
Current maturities of long-term debt	3	63
Long-Term Debt	3,570	3,569
Other	14	16
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	4	2
Regulatory assets, current	30	54
Other, current assets	57	19
Regulatory assets, noncurrent	280	303
Other, noncurrent assets	60	52
Current maturities of long-term debt		350
Long-Term Debt	$ 2,384	$ 1,788
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Other	$ 145	$ 177