Fair Value Of Financial Assets And Liabilities (Additional Fair Value Disclosure) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 44,001	$ 23,053
Debt of variable interest entities	852	949
Long-term Debt	39,461	20,573
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	10,096	10,629
Debt of variable interest entities	300	300
Long-term Debt	8,741	9,274
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	16,563	15,518
Long-term Debt	14,428	13,152
Progress Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	5,277	4,735
Long-term Debt	4,840	4,206
Progress Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	6,222	5,633
Long-term Debt	5,320	4,681
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	2,117	2,688
Long-term Debt	1,997	2,555
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	4,268	4,048
Long-term Debt	$ 3,702	$ 3,459