Stock-Based Compensation (Schedule Of Stock-Based Compensation Expense) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated fair value of stock based compensation awards allocated to purchase price.	$ 62
Allocated Share-based Compensation Expense, Net of Tax	48	32	41
Pre-tax stock-based compensation	78	52	67
Tax benefit associated with stock-based compensation	30	20	26
Stock-based compensation cost capitalized	2	2	4
Duke Energy Carolinas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	12	17	23
Progress Energy [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	25	20	16
Pre-tax stock-based compensation	39	33	27
Tax benefit associated with stock-based compensation	15	13	11
Progress Energy Carolinas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	16	12	10
Progress Energy Florida [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	9	8	7
Duke Energy Ohio [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	4	6	7
Duke Energy Indiana [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	4	4	6
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax stock-based compensation	2		2
Stock-based compensation cost capitalized		2
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax stock-based compensation	43		26
Stock-based compensation cost capitalized		27
Restricted Stock Units Awards [Member] | Progress Energy [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax stock-based compensation	27	24	21
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax stock-based compensation	33		39
Stock-based compensation cost capitalized		23
Performance Awards [Member] | Progress Energy [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax stock-based compensation	$ 12	$ 9	$ 6