Related Party Transactions(OtherRevenueAndExpense)(Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Corporate governance and shared service expenses [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 1,112	[1]	$ 1,009	[1]	$ 1,016	[1]
Corporate governance and shared service expenses [Member] | Progress Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	254	[1]	203	[1]	176	[1]
Corporate governance and shared service expenses [Member] | Progress Energy Florida [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	186	[1]	160	[1]	156	[1]
Corporate governance and shared service expenses [Member] | Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	358	[1]	401	[1]	369	[1]
Corporate governance and shared service expenses [Member] | Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	419	[1]	415	[1]	364	[1]
Indemnification Coverages [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	21	[2]	21	[2]	25	[2]
Indemnification Coverages [Member] | Progress Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	17	[2]
Indemnification Coverages [Member] | Progress Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	8	[2]
Indemnification Coverages [Member] | Progress Energy Florida [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	8	[2]
Indemnification Coverages [Member] | Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	15	[2]	17	[2]	19	[2]
Indemnification Coverages [Member] | Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	8	[2]	7	[2]	8	[2]
Joint Dispatch Agreement Revenue [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party	18	[3]
Joint Dispatch Agreement Revenue [Member] | Progress Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party	91	[3]
Joint Dispatch Agreement Revenue [Member] | Progress Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party	91	[3]
Joint Dispatch Agreement Expense [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	91	[3]
Joint Dispatch Agreement Expense [Member] | Progress Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	18	[3]
Joint Dispatch Agreement Expense [Member] | Progress Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	18	[3]
Corporate Governance And Shared Service Expenses Provided By Duke Energy [Member] | Progress Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	63	[1]
Corporate Governance And Shared Service Expenses Provided To Duke Energy [Member] | Progress Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party	$ 47	[4]

[1] The Subsidiary Registrants are charged their proportionate share of corporate governance and other costs by unconsolidated affiliates that are consolidated affiliates of Duke Energy and Progress Energy. Corporate governance and other shared services costs are primarily related to human resources, employee benefits, legal and accounting fees, as well as other third party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.

[2] The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.

[3] Effective with the consummation of the merger between Duke Energy and Progress Energy, Duke Energy Carolinas and Progress Energy Carolinas began to participate in a JDA which allowed the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Regulated electric within revenue on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power - regulated on the Consolidated Statements of Operations and Comprehensive Income.

[4] Progress Energy charges a proportionate share of corporate governance and other costs to unconsolidated affiliates that are consolidated affiliates of Duke Energy. Corporate governance and other shared costs are primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges are recorded as an offset to Operation, maintenance and other in the Statements of Operations and Comprehensive Income.