Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Allowance for doubtful accounts - receivables	$ 19	$ 16
Regulatory assets, current	1,957	2,005
Other, current assets	976	1,049
Regulatory assets, noncurrent	13,301	13,617
Other, noncurrent assets	2,969	2,935
Current maturities of long-term debt	2,501	3,406
Long-Term Debt	$ 53,681	$ 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	$ 1,587	$ 1,650
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	56	55
Regulatory assets, current	52	52
Other, current assets	152	162
Regulatory assets, noncurrent	1,032	1,041
Other, noncurrent assets	280	261
Current maturities of long-term debt	227	227
Long-Term Debt	4,065	3,998
Other	212	212
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	560	520
Other, current assets	31	72
Regulatory assets, noncurrent	3,429	3,457
Other, noncurrent assets	1,027	1,027
Current maturities of long-term debt	7	6
Long-Term Debt	10,658	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	5	5
Regulatory assets, current	1,076	1,137
Other, current assets	143	125
Regulatory assets, noncurrent	6,358	6,564
Other, noncurrent assets	1,029	974
Current maturities of long-term debt	825	1,672
Long-Term Debt	$ 18,276	$ 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	$ 341	$ 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	12	39
Regulatory assets, noncurrent	1,032	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	622	703
Other, current assets	45	62
Regulatory assets, noncurrent	4,041	4,111
Other, noncurrent assets	627	612
Current maturities of long-term debt	5	603
Long-Term Debt	8,893	7,451
Other	89	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	454	434
Other, current assets	55	46
Regulatory assets, noncurrent	2,316	2,454
Other, noncurrent assets	318	311
Current maturities of long-term debt	470	270
Long-Term Debt	6,795	7,051
Other	95	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	12	39
Regulatory assets, noncurrent	1,032	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	59	33
Other, current assets	25	24
Regulatory assets, noncurrent	501	531
Other, noncurrent assets	45	41
Current maturities of long-term debt	551	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	$ 79	$ 93
Duke Energy Indiana [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	151	175
Other, current assets	23	35
Regulatory assets, noncurrent	981	982
Other, noncurrent assets	201	194
Current maturities of long-term debt	3	63
Long-Term Debt	3,569	3,569
Other	29	16
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	4	2
Regulatory assets, current	28	54
Other, current assets	19	19
Regulatory assets, noncurrent	289	303
Other, noncurrent assets	51	52
Current maturities of long-term debt	350	350
Long-Term Debt	$ 1,788	$ 1,788
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Other	$ 158	$ 177