Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Allowance for doubtful accounts - receivables	$ 20	$ 16
Regulatory assets, current	1,723	2,005
Other, current assets	1,333	1,049
Regulatory assets, noncurrent	13,916	13,617
Other, noncurrent assets	2,905	2,935
Current maturities of long-term debt	3,096	3,406
Long-Term Debt	$ 54,818	$ 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	729,000,000	727,000,000
Other, noncurrent liabilities	$ 1,649	$ 1,650
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	53	55
Regulatory assets, current	52	52
Other, current assets	188	162
Regulatory assets, noncurrent	1,002	1,041
Other, noncurrent assets	63	261
Current maturities of long-term debt	231	227
Long-Term Debt	4,060	3,998
Other, noncurrent liabilities	218	212
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	573	520
Other, current assets	19	72
Regulatory assets, noncurrent	3,587	3,457
Other, noncurrent assets	1,061	1,027
Current maturities of long-term debt	457	6
Long-Term Debt	11,001	10,633
Other, noncurrent liabilities	617	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	881	1,137
Other, current assets	242	125
Regulatory assets, noncurrent	6,733	6,564
Other, noncurrent assets	989	974
Current maturities of long-term debt	1,276	1,672
Long-Term Debt	$ 17,693	$ 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, noncurrent liabilities	$ 361	$ 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	16	39
Regulatory assets, noncurrent	1,002	1,041
Current maturities of long-term debt	54	53
Long-Term Debt	1,631	1,636
Duke Energy Progress [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	515	703
Other, current assets	95	62
Regulatory assets, noncurrent	4,363	4,111
Other, noncurrent assets	595	612
Current maturities of long-term debt	306	603
Long-Term Debt	8,593	7,451
Other, noncurrent liabilities	105	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	367	434
Other, current assets	42	46
Regulatory assets, noncurrent	2,370	2,454
Other, noncurrent assets	307	311
Current maturities of long-term debt	621	270
Long-Term Debt	6,511	7,051
Other, noncurrent liabilities	102	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	16	39
Regulatory assets, noncurrent	1,002	1,041
Current maturities of long-term debt	54	53
Long-Term Debt	1,306	1,336
Duke Energy Ohio [Member]
Allowance for doubtful accounts - receivables	4	2
Regulatory assets, current	47	33
Other, current assets	28	24
Regulatory assets, noncurrent	553	531
Other, noncurrent assets	48	41
Current maturities of long-term debt	100	551
Long-Term Debt	$ 2,594	$ 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, noncurrent liabilities	$ 95	$ 93
Duke Energy Indiana [Member]
Allowance for doubtful accounts - receivables	3	2
Regulatory assets, current	91	175
Other, current assets	29	35
Regulatory assets, noncurrent	1,088	982
Other, noncurrent assets	211	194
Current maturities of long-term debt	651	63
Long-Term Debt	3,407	3,569
Other, noncurrent liabilities	57	16
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	5	2
Regulatory assets, current	48	54
Other, current assets	122	19
Regulatory assets, noncurrent	306	303
Other, noncurrent assets	42	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, noncurrent liabilities	$ 145	$ 177
Series A Preferred Stock [Member]
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
Series B Preferred Stock [Member]
Preferred stock, par value (in usd per share)	$ 0.001
Preferred stock, depositary shares authorized	1,000,000
Preferred stock, depositary shares outstanding	1,000,000