Related Party Transactions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Duke Energy Carolinas [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 199	[1]	$ 236	[1]	$ 638	[1]	$ 714	[1]
Duke Energy Carolinas [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	[2]	5	[2]	16	[2]	16	[2]
Duke Energy Carolinas [Member] | Joint Dispatch Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	13	[3]	24	[3]	125	[3]	101	[3]
Related party transaction, expenses from transactions with related party	36	[3]	39	[3]	127	[3]	71	[3]
Progress Energy [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party		[4]	24	[4]		[4]	74	[4]
Related party transaction, expenses from transactions with related party	182	[1]	54	[1]	560	[1]	327	[1]
Progress Energy [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	8	[2]	9	[2]	25	[2]	26	[2]
Progress Energy [Member] | Joint Dispatch Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	36	[3]	39	[3]	127	[3]	71	[3]
Related party transaction, expenses from transactions with related party	13	[3]	24	[3]	125	[3]	101	[3]
Duke Energy Progress [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	91	[1]	33	[1]	291	[1]	195	[1]
Duke Energy Progress [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	[2]	5	[2]	13	[2]	15	[2]
Duke Energy Progress [Member] | Joint Dispatch Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	36	[3]	39	[3]	127	[3]	71	[3]
Related party transaction, expenses from transactions with related party	13	[3]	24	[3]	125	[3]	101	[3]
Duke Energy Florida [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	91	[1]	20	[1]	269	[1]	131	[1]
Duke Energy Florida [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	[2]	4	[2]	12	[2]	11	[2]
Duke Energy Ohio [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	83	[1]	89	[1]	242	[1]	261	[1]
Duke Energy Ohio [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	3	[2]	3	[2]	10	[2]	11	[2]
Duke Energy Indiana [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	94	[1]	113	[1]	293	[1]	313	[1]
Duke Energy Indiana [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 3	[2]	$ 5	[2]	$ 8	[2]	$ 10	[2]

[1] The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, 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 Condensed 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 Condensed Consolidated Statements of Operations and Comprehensive Income.

[3] Duke Energy Carolinas and Duke Energy participate in a JDA which allows 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 Operating Revenues on the Condensed 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 on the Condensed Consolidated Statements of Operations and Comprehensive Income.

[4] In 2013, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Condensed Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Condensed Consolidated Statements of Changes in Common Stockholder's Equity during the nine months ended September 30, 2014.