New Accounting Standards	9 Months Ended
Sep. 30, 2011
New Accounting Standards	18. New Accounting Standards The following new accounting standards were adopted by the Duke Energy Registrants subsequent to September 30, 2010 and the impact of such adoption, if applicable, has been presented in the respective Condensed Consolidated Financial Statements of the Duke Energy Registrants: Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605—Revenue Recognition (ASC 605). In October 2009, the FASB issued new revenue recognition accounting guidance in response to practice concerns related to the accounting for revenue arrangements with multiple deliverables. This new accounting guidance primarily applies to all contractual arrangements in which a vendor will perform multiple revenue generating activities and addresses the unit of accounting for arrangements involving multiple deliverables, as well as how arrangement consideration should be allocated to the separate units of accounting. For the Duke Energy Registrants, the new accounting guidance was effective January 1, 2011 and applied on a prospective basis. This new accounting guidance did not have a material impact to the consolidated results of operations, cash flows or financial position of the Duke Energy Registrants. ASC 805—Business Combinations (ASC 805). In November 2010, the FASB issued new accounting guidance in response to diversity in the interpretation of pro forma information disclosure requirements for business combinations. The new accounting guidance requires an entity to present pro forma financial information as if a business combination occurred at the beginning of the earliest period presented as well as additional disclosures describing the nature and amount of material, nonrecurring pro forma adjustments. This new accounting guidance was effective January 1, 2011 and will be applied to all business combinations consummated after that date. ASC 820—Fair Value Measurements and Disclosures (ASC 820). In January 2010, the FASB amended existing fair value measurements and disclosures accounting guidance to clarify certain existing disclosure requirements and to require a number of additional disclosures, including amounts and reasons for significant transfers between the three levels of the fair value hierarchy, and presentation of certain information in the reconciliation of recurring Level 3 measurements on a gross basis. For the Duke Energy Registrants, certain portions of this revised accounting guidance were effective on January 1, 2010, with additional disclosures effective for periods beginning January 1, 2011. The adoption of this accounting guidance resulted in additional disclosure in the notes to the consolidated financial statements but did not have an impact on the Duke Energy Registrants' consolidated results of operations, cash flows or financial position. See note 9 for additional disclosures required by the revised accounting guidance in ASC 820. ASC 350–Intangibles–Goodwill and Other. In September 2011, the FASB amended existing goodwill impairment testing accounting guidance to provide an entity testing goodwill for impairment with the option of performing a qualitative assessment prior to calculating the fair value of a reporting unit in step one of a goodwill impairment test. Under this revised guidance, a qualitative assessment would require an evaluation of economic, industry, and company-specific considerations. If an entity determines, on a basis of such qualitative factors, that the fair value of a reporting unit is more likely than not less than the carrying value of a reporting unit, the two-step impairment test, as currently required under existing applicable accounting guidance, would be required. Otherwise, no further impairment testing would be required. The revised goodwill impairment testing accounting guidance is effective for the Duke Energy Registrants' annual and interim goodwill impairment tests performed for fiscal years beginning January 1, 2012, with early adoption of this revised guidance permitted for annual and interim goodwill impairment tests performed as of a date before September 15, 2011. Since annual goodwill impairment tests are performed by Duke Energy as of August 31, the Duke Energy Registrants early adopted this revised accounting guidance during the third quarter of 2011 and applied that guidance to their annual goodwill impairment tests for 2011. The following new Accounting Standards Updates (ASU) have been issued, but have not yet been adopted by Duke Energy, as of September 30, 2011: ASC 820—Fair Value Measurements and Disclosures (ASC 820). In May 2011, the FASB amended existing requirements for measuring fair value and for disclosing information about fair value measurements. This revised guidance results in a consistent definition of fair value, as well as common requirements for measurement and disclosure of fair value information between U.S. GAAP and International Financial Reporting Standards (IFRS). In addition, the amendments set forth enhanced disclosure requirements with respect to recurring Level 3 measurements, nonfinancial assets measured or disclosed at fair value, transfers between levels in the fair value hierarchy, and assets and liabilities disclosed but not recorded at fair value. For the Duke Energy Registrants, the revised fair value measurement guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2012. Duke Energy is currently evaluating the potential impact of the adoption of this revised guidance and is unable to estimate at this time the impact of adoption on its consolidated results of operations, cash flows, or financial position. ASC 220—Comprehensive Income (ASC 220). In June 2011, the FASB amended the existing requirements for presenting comprehensive income in financial statements primarily to increase the prominence of items reported in other comprehensive income (OCI) and to facilitate the convergence of U.S. GAAP and IFRS. Specifically, the revised guidance eliminates the option currently provided under existing requirements to present components of OCI as part of the statement of changes in stockholders' equity. Accordingly, all non-owner changes in stockholders' equity will be required to be presented either in a single continuous statement of comprehensive income or in two separate but consecutive financial statements. For the Duke Energy Registrants, this revised guidance is effective on a retrospective basis for interim and annual periods beginning January 1, 2012. Early adoption of this revised guidance is permitted. Duke Energy is currently evaluating the revised requirements for presenting comprehensive income in its financial statements and is unable to estimate at this time the impact of adoption of this revised guidance on its consolidated results of operations, cash flows or financial position.
Duke Energy Corp [Member]
New Accounting Standards	18. New Accounting Standards The following new accounting standards were adopted by the Duke Energy Registrants subsequent to September 30, 2010 and the impact of such adoption, if applicable, has been presented in the respective Condensed Consolidated Financial Statements of the Duke Energy Registrants: Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605—Revenue Recognition (ASC 605). In October 2009, the FASB issued new revenue recognition accounting guidance in response to practice concerns related to the accounting for revenue arrangements with multiple deliverables. This new accounting guidance primarily applies to all contractual arrangements in which a vendor will perform multiple revenue generating activities and addresses the unit of accounting for arrangements involving multiple deliverables, as well as how arrangement consideration should be allocated to the separate units of accounting. For the Duke Energy Registrants, the new accounting guidance was effective January 1, 2011 and applied on a prospective basis. This new accounting guidance did not have a material impact to the consolidated results of operations, cash flows or financial position of the Duke Energy Registrants. ASC 805—Business Combinations (ASC 805). In November 2010, the FASB issued new accounting guidance in response to diversity in the interpretation of pro forma information disclosure requirements for business combinations. The new accounting guidance requires an entity to present pro forma financial information as if a business combination occurred at the beginning of the earliest period presented as well as additional disclosures describing the nature and amount of material, nonrecurring pro forma adjustments. This new accounting guidance was effective January 1, 2011 and will be applied to all business combinations consummated after that date. ASC 820—Fair Value Measurements and Disclosures (ASC 820). In January 2010, the FASB amended existing fair value measurements and disclosures accounting guidance to clarify certain existing disclosure requirements and to require a number of additional disclosures, including amounts and reasons for significant transfers between the three levels of the fair value hierarchy, and presentation of certain information in the reconciliation of recurring Level 3 measurements on a gross basis. For the Duke Energy Registrants, certain portions of this revised accounting guidance were effective on January 1, 2010, with additional disclosures effective for periods beginning January 1, 2011. The adoption of this accounting guidance resulted in additional disclosure in the notes to the consolidated financial statements but did not have an impact on the Duke Energy Registrants' consolidated results of operations, cash flows or financial position. See note 9 for additional disclosures required by the revised accounting guidance in ASC 820. ASC 350–Intangibles–Goodwill and Other. In September 2011, the FASB amended existing goodwill impairment testing accounting guidance to provide an entity testing goodwill for impairment with the option of performing a qualitative assessment prior to calculating the fair value of a reporting unit in step one of a goodwill impairment test. Under this revised guidance, a qualitative assessment would require an evaluation of economic, industry, and company-specific considerations. If an entity determines, on a basis of such qualitative factors, that the fair value of a reporting unit is more likely than not less than the carrying value of a reporting unit, the two-step impairment test, as currently required under existing applicable accounting guidance, would be required. Otherwise, no further impairment testing would be required. The revised goodwill impairment testing accounting guidance is effective for the Duke Energy Registrants' annual and interim goodwill impairment tests performed for fiscal years beginning January 1, 2012, with early adoption of this revised guidance permitted for annual and interim goodwill impairment tests performed as of a date before September 15, 2011. Since annual goodwill impairment tests are performed by Duke Energy as of August 31, the Duke Energy Registrants early adopted this revised accounting guidance during the third quarter of 2011 and applied that guidance to their annual goodwill impairment tests for 2011. The following new Accounting Standards Updates (ASU) have been issued, but have not yet been adopted by Duke Energy, as of September 30, 2011: ASC 820—Fair Value Measurements and Disclosures (ASC 820). In May 2011, the FASB amended existing requirements for measuring fair value and for disclosing information about fair value measurements. This revised guidance results in a consistent definition of fair value, as well as common requirements for measurement and disclosure of fair value information between U.S. GAAP and International Financial Reporting Standards (IFRS). In addition, the amendments set forth enhanced disclosure requirements with respect to recurring Level 3 measurements, nonfinancial assets measured or disclosed at fair value, transfers between levels in the fair value hierarchy, and assets and liabilities disclosed but not recorded at fair value. For the Duke Energy Registrants, the revised fair value measurement guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2012. Duke Energy is currently evaluating the potential impact of the adoption of this revised guidance and is unable to estimate at this time the impact of adoption on its consolidated results of operations, cash flows, or financial position. ASC 220—Comprehensive Income (ASC 220). In June 2011, the FASB amended the existing requirements for presenting comprehensive income in financial statements primarily to increase the prominence of items reported in other comprehensive income (OCI) and to facilitate the convergence of U.S. GAAP and IFRS. Specifically, the revised guidance eliminates the option currently provided under existing requirements to present components of OCI as part of the statement of changes in stockholders' equity. Accordingly, all non-owner changes in stockholders' equity will be required to be presented either in a single continuous statement of comprehensive income or in two separate but consecutive financial statements. For the Duke Energy Registrants, this revised guidance is effective on a retrospective basis for interim and annual periods beginning January 1, 2012. Early adoption of this revised guidance is permitted. Duke Energy is currently evaluating the revised requirements for presenting comprehensive income in its financial statements and is unable to estimate at this time the impact of adoption of this revised guidance on its consolidated results of operations, cash flows or financial position.
Duke Energy Carolinas [Member]
New Accounting Standards	18. New Accounting Standards The following new accounting standards were adopted by the Duke Energy Registrants subsequent to September 30, 2010 and the impact of such adoption, if applicable, has been presented in the respective Condensed Consolidated Financial Statements of the Duke Energy Registrants: Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605—Revenue Recognition (ASC 605). In October 2009, the FASB issued new revenue recognition accounting guidance in response to practice concerns related to the accounting for revenue arrangements with multiple deliverables. This new accounting guidance primarily applies to all contractual arrangements in which a vendor will perform multiple revenue generating activities and addresses the unit of accounting for arrangements involving multiple deliverables, as well as how arrangement consideration should be allocated to the separate units of accounting. For the Duke Energy Registrants, the new accounting guidance was effective January 1, 2011 and applied on a prospective basis. This new accounting guidance did not have a material impact to the consolidated results of operations, cash flows or financial position of the Duke Energy Registrants. ASC 805—Business Combinations (ASC 805). In November 2010, the FASB issued new accounting guidance in response to diversity in the interpretation of pro forma information disclosure requirements for business combinations. The new accounting guidance requires an entity to present pro forma financial information as if a business combination occurred at the beginning of the earliest period presented as well as additional disclosures describing the nature and amount of material, nonrecurring pro forma adjustments. This new accounting guidance was effective January 1, 2011 and will be applied to all business combinations consummated after that date. ASC 820—Fair Value Measurements and Disclosures (ASC 820). In January 2010, the FASB amended existing fair value measurements and disclosures accounting guidance to clarify certain existing disclosure requirements and to require a number of additional disclosures, including amounts and reasons for significant transfers between the three levels of the fair value hierarchy, and presentation of certain information in the reconciliation of recurring Level 3 measurements on a gross basis. For the Duke Energy Registrants, certain portions of this revised accounting guidance were effective on January 1, 2010, with additional disclosures effective for periods beginning January 1, 2011. The adoption of this accounting guidance resulted in additional disclosure in the notes to the consolidated financial statements but did not have an impact on the Duke Energy Registrants' consolidated results of operations, cash flows or financial position. See note 9 for additional disclosures required by the revised accounting guidance in ASC 820. ASC 350–Intangibles–Goodwill and Other. In September 2011, the FASB amended existing goodwill impairment testing accounting guidance to provide an entity testing goodwill for impairment with the option of performing a qualitative assessment prior to calculating the fair value of a reporting unit in step one of a goodwill impairment test. Under this revised guidance, a qualitative assessment would require an evaluation of economic, industry, and company-specific considerations. If an entity determines, on a basis of such qualitative factors, that the fair value of a reporting unit is more likely than not less than the carrying value of a reporting unit, the two-step impairment test, as currently required under existing applicable accounting guidance, would be required. Otherwise, no further impairment testing would be required. The revised goodwill impairment testing accounting guidance is effective for the Duke Energy Registrants' annual and interim goodwill impairment tests performed for fiscal years beginning January 1, 2012, with early adoption of this revised guidance permitted for annual and interim goodwill impairment tests performed as of a date before September 15, 2011. Since annual goodwill impairment tests are performed by Duke Energy as of August 31, the Duke Energy Registrants early adopted this revised accounting guidance during the third quarter of 2011 and applied that guidance to their annual goodwill impairment tests for 2011. The following new Accounting Standards Updates (ASU) have been issued, but have not yet been adopted by Duke Energy, as of September 30, 2011: ASC 820—Fair Value Measurements and Disclosures (ASC 820). In May 2011, the FASB amended existing requirements for measuring fair value and for disclosing information about fair value measurements. This revised guidance results in a consistent definition of fair value, as well as common requirements for measurement and disclosure of fair value information between U.S. GAAP and International Financial Reporting Standards (IFRS). In addition, the amendments set forth enhanced disclosure requirements with respect to recurring Level 3 measurements, nonfinancial assets measured or disclosed at fair value, transfers between levels in the fair value hierarchy, and assets and liabilities disclosed but not recorded at fair value. For the Duke Energy Registrants, the revised fair value measurement guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2012. Duke Energy is currently evaluating the potential impact of the adoption of this revised guidance and is unable to estimate at this time the impact of adoption on its consolidated results of operations, cash flows, or financial position. ASC 220—Comprehensive Income (ASC 220). In June 2011, the FASB amended the existing requirements for presenting comprehensive income in financial statements primarily to increase the prominence of items reported in other comprehensive income (OCI) and to facilitate the convergence of U.S. GAAP and IFRS. Specifically, the revised guidance eliminates the option currently provided under existing requirements to present components of OCI as part of the statement of changes in stockholders' equity. Accordingly, all non-owner changes in stockholders' equity will be required to be presented either in a single continuous statement of comprehensive income or in two separate but consecutive financial statements. For the Duke Energy Registrants, this revised guidance is effective on a retrospective basis for interim and annual periods beginning January 1, 2012. Early adoption of this revised guidance is permitted. Duke Energy is currently evaluating the revised requirements for presenting comprehensive income in its financial statements and is unable to estimate at this time the impact of adoption of this revised guidance on its consolidated results of operations, cash flows or financial position.
Duke Energy Ohio [Member]
New Accounting Standards	18. New Accounting Standards The following new accounting standards were adopted by the Duke Energy Registrants subsequent to September 30, 2010 and the impact of such adoption, if applicable, has been presented in the respective Condensed Consolidated Financial Statements of the Duke Energy Registrants: Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605—Revenue Recognition (ASC 605). In October 2009, the FASB issued new revenue recognition accounting guidance in response to practice concerns related to the accounting for revenue arrangements with multiple deliverables. This new accounting guidance primarily applies to all contractual arrangements in which a vendor will perform multiple revenue generating activities and addresses the unit of accounting for arrangements involving multiple deliverables, as well as how arrangement consideration should be allocated to the separate units of accounting. For the Duke Energy Registrants, the new accounting guidance was effective January 1, 2011 and applied on a prospective basis. This new accounting guidance did not have a material impact to the consolidated results of operations, cash flows or financial position of the Duke Energy Registrants. ASC 805—Business Combinations (ASC 805). In November 2010, the FASB issued new accounting guidance in response to diversity in the interpretation of pro forma information disclosure requirements for business combinations. The new accounting guidance requires an entity to present pro forma financial information as if a business combination occurred at the beginning of the earliest period presented as well as additional disclosures describing the nature and amount of material, nonrecurring pro forma adjustments. This new accounting guidance was effective January 1, 2011 and will be applied to all business combinations consummated after that date. ASC 820—Fair Value Measurements and Disclosures (ASC 820). In January 2010, the FASB amended existing fair value measurements and disclosures accounting guidance to clarify certain existing disclosure requirements and to require a number of additional disclosures, including amounts and reasons for significant transfers between the three levels of the fair value hierarchy, and presentation of certain information in the reconciliation of recurring Level 3 measurements on a gross basis. For the Duke Energy Registrants, certain portions of this revised accounting guidance were effective on January 1, 2010, with additional disclosures effective for periods beginning January 1, 2011. The adoption of this accounting guidance resulted in additional disclosure in the notes to the consolidated financial statements but did not have an impact on the Duke Energy Registrants' consolidated results of operations, cash flows or financial position. See note 9 for additional disclosures required by the revised accounting guidance in ASC 820. ASC 350–Intangibles–Goodwill and Other. In September 2011, the FASB amended existing goodwill impairment testing accounting guidance to provide an entity testing goodwill for impairment with the option of performing a qualitative assessment prior to calculating the fair value of a reporting unit in step one of a goodwill impairment test. Under this revised guidance, a qualitative assessment would require an evaluation of economic, industry, and company-specific considerations. If an entity determines, on a basis of such qualitative factors, that the fair value of a reporting unit is more likely than not less than the carrying value of a reporting unit, the two-step impairment test, as currently required under existing applicable accounting guidance, would be required. Otherwise, no further impairment testing would be required. The revised goodwill impairment testing accounting guidance is effective for the Duke Energy Registrants' annual and interim goodwill impairment tests performed for fiscal years beginning January 1, 2012, with early adoption of this revised guidance permitted for annual and interim goodwill impairment tests performed as of a date before September 15, 2011. Since annual goodwill impairment tests are performed by Duke Energy as of August 31, the Duke Energy Registrants early adopted this revised accounting guidance during the third quarter of 2011 and applied that guidance to their annual goodwill impairment tests for 2011. The following new Accounting Standards Updates (ASU) have been issued, but have not yet been adopted by Duke Energy, as of September 30, 2011: ASC 820—Fair Value Measurements and Disclosures (ASC 820). In May 2011, the FASB amended existing requirements for measuring fair value and for disclosing information about fair value measurements. This revised guidance results in a consistent definition of fair value, as well as common requirements for measurement and disclosure of fair value information between U.S. GAAP and International Financial Reporting Standards (IFRS). In addition, the amendments set forth enhanced disclosure requirements with respect to recurring Level 3 measurements, nonfinancial assets measured or disclosed at fair value, transfers between levels in the fair value hierarchy, and assets and liabilities disclosed but not recorded at fair value. For the Duke Energy Registrants, the revised fair value measurement guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2012. Duke Energy is currently evaluating the potential impact of the adoption of this revised guidance and is unable to estimate at this time the impact of adoption on its consolidated results of operations, cash flows, or financial position. ASC 220—Comprehensive Income (ASC 220). In June 2011, the FASB amended the existing requirements for presenting comprehensive income in financial statements primarily to increase the prominence of items reported in other comprehensive income (OCI) and to facilitate the convergence of U.S. GAAP and IFRS. Specifically, the revised guidance eliminates the option currently provided under existing requirements to present components of OCI as part of the statement of changes in stockholders' equity. Accordingly, all non-owner changes in stockholders' equity will be required to be presented either in a single continuous statement of comprehensive income or in two separate but consecutive financial statements. For the Duke Energy Registrants, this revised guidance is effective on a retrospective basis for interim and annual periods beginning January 1, 2012. Early adoption of this revised guidance is permitted. Duke Energy is currently evaluating the revised requirements for presenting comprehensive income in its financial statements and is unable to estimate at this time the impact of adoption of this revised guidance on its consolidated results of operations, cash flows or financial position.
Duke Energy Indiana [Member]
New Accounting Standards	18. New Accounting Standards The following new accounting standards were adopted by the Duke Energy Registrants subsequent to September 30, 2010 and the impact of such adoption, if applicable, has been presented in the respective Condensed Consolidated Financial Statements of the Duke Energy Registrants: Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605—Revenue Recognition (ASC 605). In October 2009, the FASB issued new revenue recognition accounting guidance in response to practice concerns related to the accounting for revenue arrangements with multiple deliverables. This new accounting guidance primarily applies to all contractual arrangements in which a vendor will perform multiple revenue generating activities and addresses the unit of accounting for arrangements involving multiple deliverables, as well as how arrangement consideration should be allocated to the separate units of accounting. For the Duke Energy Registrants, the new accounting guidance was effective January 1, 2011 and applied on a prospective basis. This new accounting guidance did not have a material impact to the consolidated results of operations, cash flows or financial position of the Duke Energy Registrants. ASC 805—Business Combinations (ASC 805). In November 2010, the FASB issued new accounting guidance in response to diversity in the interpretation of pro forma information disclosure requirements for business combinations. The new accounting guidance requires an entity to present pro forma financial information as if a business combination occurred at the beginning of the earliest period presented as well as additional disclosures describing the nature and amount of material, nonrecurring pro forma adjustments. This new accounting guidance was effective January 1, 2011 and will be applied to all business combinations consummated after that date. ASC 820—Fair Value Measurements and Disclosures (ASC 820). In January 2010, the FASB amended existing fair value measurements and disclosures accounting guidance to clarify certain existing disclosure requirements and to require a number of additional disclosures, including amounts and reasons for significant transfers between the three levels of the fair value hierarchy, and presentation of certain information in the reconciliation of recurring Level 3 measurements on a gross basis. For the Duke Energy Registrants, certain portions of this revised accounting guidance were effective on January 1, 2010, with additional disclosures effective for periods beginning January 1, 2011. The adoption of this accounting guidance resulted in additional disclosure in the notes to the consolidated financial statements but did not have an impact on the Duke Energy Registrants' consolidated results of operations, cash flows or financial position. See note 9 for additional disclosures required by the revised accounting guidance in ASC 820. ASC 350–Intangibles–Goodwill and Other. In September 2011, the FASB amended existing goodwill impairment testing accounting guidance to provide an entity testing goodwill for impairment with the option of performing a qualitative assessment prior to calculating the fair value of a reporting unit in step one of a goodwill impairment test. Under this revised guidance, a qualitative assessment would require an evaluation of economic, industry, and company-specific considerations. If an entity determines, on a basis of such qualitative factors, that the fair value of a reporting unit is more likely than not less than the carrying value of a reporting unit, the two-step impairment test, as currently required under existing applicable accounting guidance, would be required. Otherwise, no further impairment testing would be required. The revised goodwill impairment testing accounting guidance is effective for the Duke Energy Registrants' annual and interim goodwill impairment tests performed for fiscal years beginning January 1, 2012, with early adoption of this revised guidance permitted for annual and interim goodwill impairment tests performed as of a date before September 15, 2011. Since annual goodwill impairment tests are performed by Duke Energy as of August 31, the Duke Energy Registrants early adopted this revised accounting guidance during the third quarter of 2011 and applied that guidance to their annual goodwill impairment tests for 2011. The following new Accounting Standards Updates (ASU) have been issued, but have not yet been adopted by Duke Energy, as of September 30, 2011: ASC 820—Fair Value Measurements and Disclosures (ASC 820). In May 2011, the FASB amended existing requirements for measuring fair value and for disclosing information about fair value measurements. This revised guidance results in a consistent definition of fair value, as well as common requirements for measurement and disclosure of fair value information between U.S. GAAP and International Financial Reporting Standards (IFRS). In addition, the amendments set forth enhanced disclosure requirements with respect to recurring Level 3 measurements, nonfinancial assets measured or disclosed at fair value, transfers between levels in the fair value hierarchy, and assets and liabilities disclosed but not recorded at fair value. For the Duke Energy Registrants, the revised fair value measurement guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2012. Duke Energy is currently evaluating the potential impact of the adoption of this revised guidance and is unable to estimate at this time the impact of adoption on its consolidated results of operations, cash flows, or financial position. ASC 220—Comprehensive Income (ASC 220). In June 2011, the FASB amended the existing requirements for presenting comprehensive income in financial statements primarily to increase the prominence of items reported in other comprehensive income (OCI) and to facilitate the convergence of U.S. GAAP and IFRS. Specifically, the revised guidance eliminates the option currently provided under existing requirements to present components of OCI as part of the statement of changes in stockholders' equity. Accordingly, all non-owner changes in stockholders' equity will be required to be presented either in a single continuous statement of comprehensive income or in two separate but consecutive financial statements. For the Duke Energy Registrants, this revised guidance is effective on a retrospective basis for interim and annual periods beginning January 1, 2012. Early adoption of this revised guidance is permitted. Duke Energy is currently evaluating the revised requirements for presenting comprehensive income in its financial statements and is unable to estimate at this time the impact of adoption of this revised guidance on its consolidated results of operations, cash flows or financial position.

18. New Accounting Standards

The following new accounting standards were adopted by the Duke Energy Registrants subsequent to September 30, 2010 and the impact of such adoption, if applicable, has been presented in the respective Condensed Consolidated Financial Statements of the Duke Energy Registrants:

Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605—Revenue Recognition (ASC 605). In October 2009, the FASB issued new revenue recognition accounting guidance in response to practice concerns related to the accounting for revenue arrangements with multiple deliverables. This new accounting guidance primarily applies to all contractual arrangements in which a vendor will perform multiple revenue generating activities and addresses the unit of accounting for arrangements involving multiple deliverables, as well as how arrangement consideration should be allocated to the separate units of accounting. For the Duke Energy Registrants, the new accounting guidance was effective January 1, 2011 and applied on a prospective basis. This new accounting guidance did not have a material impact to the consolidated results of operations, cash flows or financial position of the Duke Energy Registrants.

ASC 805—Business Combinations (ASC 805). In November 2010, the FASB issued new accounting guidance in response to diversity in the interpretation of pro forma information disclosure requirements for business combinations. The new accounting guidance requires an entity to present pro forma financial information as if a business combination occurred at the beginning of the earliest period presented as well as additional disclosures describing the nature and amount of material, nonrecurring pro forma adjustments. This new accounting guidance was effective January 1, 2011 and will be applied to all business combinations consummated after that date.

ASC 820—Fair Value Measurements and Disclosures (ASC 820). In January 2010, the FASB amended existing fair value measurements and disclosures accounting guidance to clarify certain existing disclosure requirements and to require a number of additional disclosures, including amounts and reasons for significant transfers between the three levels of the fair value hierarchy, and presentation of certain information in the reconciliation of recurring Level 3 measurements on a gross basis. For the Duke Energy Registrants, certain portions of this revised accounting guidance were effective on January 1, 2010, with additional disclosures effective for periods beginning January 1, 2011. The adoption of this accounting guidance resulted in additional disclosure in the notes to the consolidated financial statements but did not have an impact on the Duke Energy Registrants' consolidated results of operations, cash flows or financial position. See note 9 for additional disclosures required by the revised accounting guidance in ASC 820.

ASC 350–Intangibles–Goodwill and Other. In September 2011, the FASB amended existing goodwill impairment testing accounting guidance to provide an entity testing goodwill for impairment with the option of performing a qualitative assessment prior to calculating the fair value of a reporting unit in step one of a goodwill impairment test. Under this revised guidance, a qualitative assessment would require an evaluation of economic, industry, and company-specific considerations. If an entity determines, on a basis of such qualitative factors, that the fair value of a reporting unit is more likely than not less than the carrying value of a reporting unit, the two-step impairment test, as currently required under existing applicable accounting guidance, would be required. Otherwise, no further impairment testing would be required. The revised goodwill impairment testing accounting guidance is effective for the Duke Energy Registrants' annual and interim goodwill impairment tests performed for fiscal years beginning January 1, 2012, with early adoption of this revised guidance permitted for annual and interim goodwill impairment tests performed as of a date before September 15, 2011. Since annual goodwill impairment tests are performed by Duke Energy as of August 31, the Duke Energy Registrants early adopted this revised accounting guidance during the third quarter of 2011 and applied that guidance to their annual goodwill impairment tests for 2011.

The following new Accounting Standards Updates (ASU) have been issued, but have not yet been adopted by Duke Energy, as of September 30, 2011:

ASC 820—Fair Value Measurements and Disclosures (ASC 820). In May 2011, the FASB amended existing requirements for measuring fair value and for disclosing information about fair value measurements. This revised guidance results in a consistent definition of fair value, as well as common requirements for measurement and disclosure of fair value information between U.S. GAAP and International Financial Reporting Standards (IFRS). In addition, the amendments set forth enhanced disclosure requirements with respect to recurring Level 3 measurements, nonfinancial assets measured or disclosed at fair value, transfers between levels in the fair value hierarchy, and assets and liabilities disclosed but not recorded at fair value. For the Duke Energy Registrants, the revised fair value measurement guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2012. Duke Energy is currently evaluating the potential impact of the adoption of this revised guidance and is unable to estimate at this time the impact of adoption on its consolidated results of operations, cash flows, or financial position.

ASC 220—Comprehensive Income (ASC 220). In June 2011, the FASB amended the existing requirements for presenting comprehensive income in financial statements primarily to increase the prominence of items reported in other comprehensive income (OCI) and to facilitate the convergence of U.S. GAAP and IFRS. Specifically, the revised guidance eliminates the option currently provided under existing requirements to present components of OCI as part of the statement of changes in stockholders' equity. Accordingly, all non-owner changes in stockholders' equity will be required to be presented either in a single continuous statement of comprehensive income or in two separate but consecutive financial statements. For the Duke Energy Registrants, this revised guidance is effective on a retrospective basis for interim and annual periods beginning January 1, 2012. Early adoption of this revised guidance is permitted. Duke Energy is currently evaluating the revised requirements for presenting comprehensive income in its financial statements and is unable to estimate at this time the impact of adoption of this revised guidance on its consolidated results of operations, cash flows or financial position.

New Accounting Standards