Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Allowance for doubtful accounts - receivables	$ 18	$ 14
Regulatory assets, current	1,741	1,437
Other, current assets	437	634
Regulatory assets, noncurrent	12,505	12,442
Current maturities of long-term debt	2,852	3,244
Long-Term Debt	$ 49,863	$ 49,035
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	712,000,000	700,000,000
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	$ 56	$ 54
Regulatory assets, current	51	51
Regulatory assets, noncurrent	1,071	1,091
Current maturities of long-term debt	229	225
Long-Term Debt	4,179	4,306
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	420	299
Other, current assets	21	19
Regulatory assets, noncurrent	3,234	2,853
Current maturities of long-term debt	505	1,205
Long-Term Debt	9,589	8,598
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	4
Regulatory assets, current	970	741
Other, current assets	356	334
Regulatory assets, noncurrent	5,736	6,010
Current maturities of long-term debt	1,321	771
Long-Term Debt	$ 16,723	$ 16,916
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	51
Regulatory assets, noncurrent	1,071	1,091
Current maturities of long-term debt	53	53
Long-Term Debt	1,660	1,689
Duke Energy Progress [Member]
Allowance for doubtful accounts - receivables	2	1
Regulatory assets, current	532	352
Other, current assets	33	97
Regulatory assets, noncurrent	3,573	3,507
Current maturities of long-term debt	603	3
Long-Term Debt	6,605	7,204
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	439	389
Other, current assets	183	86
Regulatory assets, noncurrent	2,163	2,503
Current maturities of long-term debt	269	768
Long-Term Debt	7,183	6,327
Duke Energy Florida [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	2	2
Regulatory assets, current	51	51
Other, current assets	13	40
Regulatory assets, noncurrent	1,071	1,091
Current maturities of long-term debt	53	53
Long-Term Debt	1,361	1,389
Duke Energy Ohio [Member]
Allowance for doubtful accounts - receivables	3	3
Regulatory assets, current	46	49
Other, current assets	30	39
Regulatory assets, noncurrent	425	445
Current maturities of long-term debt	452	3
Long-Term Debt	$ 1,589	$ 2,039
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	$ 2	$ 2
Regulatory assets, current	191	165
Other, current assets	52	30
Regulatory assets, noncurrent	1,021	978
Current maturities of long-term debt	62	3
Long-Term Debt	3,570	3,630
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	3	2
Regulatory assets, current	35	95
Other, current assets	36	52
Regulatory assets, noncurrent	297	283
Current maturities of long-term debt	250	250
Long-Term Debt	$ 1,787	$ 1,787
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100