Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Allowance for doubtful accounts - receivables	$ 13	$ 14
Regulatory assets, current	1,109	1,023
Other, current assets	433	458
Regulatory assets, noncurrent	13,367	12,878
Current maturities of long-term debt	2,485	2,319
Long-Term Debt	$ 48,929	$ 45,576
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	700,000,000	700,000,000
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	$ 54	$ 54
Regulatory assets, current	51	50
Regulatory assets, noncurrent	1,101	1,142
Current maturities of long-term debt	215	260
Long-Term Debt	4,219	3,587
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	237	238
Other, current assets	27	37
Regulatory assets, noncurrent	3,077	3,159
Current maturities of long-term debt	705	116
Long-Term Debt	8,520	9,187
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	4	6
Regulatory assets, current	440	401
Other, current assets	243	148
Regulatory assets, noncurrent	6,438	5,722
Current maturities of long-term debt	770	778
Long-Term Debt	$ 16,717	$ 15,590
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Progress Energy [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	$ 7	$ 7
Regulatory assets, current	51	50
Regulatory assets, noncurrent	1,101	1,142
Current maturities of long-term debt	53	62
Long-Term Debt	1,689	1,741
Duke Energy Progress [Member]
Allowance for doubtful accounts - receivables	1	4
Regulatory assets, current	230	188
Other, current assets	40	57
Regulatory assets, noncurrent	3,588	3,243
Current maturities of long-term debt	203	452
Long-Term Debt	7,204	6,409
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	2
Regulatory assets, current	211	213
Other, current assets	154	125
Regulatory assets, noncurrent	2,850	2,480
Current maturities of long-term debt	567	326
Long-Term Debt	6,129	5,799
Duke Energy Florida [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	2	2
Regulatory assets, current	51	50
Other, current assets	20	53
Regulatory assets, noncurrent	1,101	1,142
Current maturities of long-term debt	53	62
Long-Term Debt	1,389	1,442
Duke Energy Ohio [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	57	37
Other, current assets	18	37
Regulatory assets, noncurrent	510	520
Current maturities of long-term debt		1
Long-Term Debt	$ 2,042	$ 1,858
Common stock, par value	$ 8.50	$ 8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	90,000,000	90,000,000
Duke Energy Indiana [Member]
Allowance for doubtful accounts - receivables	$ 1	$ 1
Regulatory assets, current	158	149
Other, current assets	34	45
Regulatory assets, noncurrent	1,123	1,073
Current maturities of long-term debt	3	3
Long-Term Debt	3,632	3,633
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	2	3
Regulatory assets, current	133	124
Other, current assets	31	12
Regulatory assets, noncurrent	322	373
Current maturities of long-term debt		35
Long-Term Debt	$ 2,036	$ 1,786
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100