Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts - receivables	$ 17	$ 14
Regulatory assets, current	1,544	1,437
Other, current assets	422	634
Regulatory assets, noncurrent	12,218	12,442
Current maturities of long-term debt	3,951	3,244
Long-Term Debt	$ 49,030	$ 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	701,000,000	700,000,000
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	$ 57	$ 54
Regulatory assets, current	51	51
Regulatory assets, noncurrent	1,082	1,091
Current maturities of long-term debt	225	225
Long-Term Debt	4,275	4,306
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	331	299
Other, current assets	42	19
Regulatory assets, noncurrent	2,825	2,853
Current maturities of long-term debt	805	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	4	4
Regulatory assets, current	869	741
Other, current assets	259	334
Regulatory assets, noncurrent	5,872	6,010
Current maturities of long-term debt	1,820	771
Long-Term Debt	$ 15,787	$ 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	1,082	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	476	352
Other, current assets	55	97
Regulatory assets, noncurrent	3,480	3,507
Current maturities of long-term debt	603	3
Long-Term Debt	6,604	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	393	389
Other, current assets	40	86
Regulatory assets, noncurrent	2,391	2,503
Current maturities of long-term debt	768	768
Long-Term Debt	6,247	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	1,082	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	43	49
Other, current assets	24	39
Regulatory assets, noncurrent	432	445
Current maturities of long-term debt	3	3
Long-Term Debt	$ 2,039	$ 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	170	165
Other, current assets	30	30
Regulatory assets, noncurrent	976	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	4	2
Regulatory assets, current	48	95
Other, current assets	21	52
Regulatory assets, noncurrent	274	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