Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2016

Related Party Transaction [Line Items]

Schedule of New Accounting Pronouncements

The following table provides a brief description of recent accounting pronouncements that could have a material impact on our consolidated financial statements:

Accounting Standard	Description	Date of Adoption	Effect on the financial statements upon adoption
New Accounting Standards Adopted
2015-15, Interest - Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements	Given the absence of authoritative guidance within ASU 2015-03, this standard clarifies that the SEC Staff would not object to an entity presenting debt issuance costs related to line-of-credit arrangements as an asset that is subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. Transition method: retrospective.	January 1, 2016	Deferred financing costs related to lines-of-credit of approximately $3.1 million recorded within Other deferred assets were not reclassified.
2015-03, Interest - Imputation of Interest (Subtopic 835-30)	The standard simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the standard. Transition method: retrospective.	January 1, 2016	Deferred financing costs of approximately $2.1 million previously classified within Other prepayments and current assets and $14.0 million previously classified within Other deferred assets were reclassified to reduce the related debt liabilities.

Accounting Standard	Description	Date of Adoption	Effect on the financial statements upon adoption
2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis	The standard makes targeted amendments to the current consolidation guidance and ends the deferral granted to investment companies from applying the VIE guidance. The standard amends the evaluation of whether (1) fees paid to a decision-maker or service providers represent a variable interest, (2) a limited partnership or similar entity has the characteristics of a VIE and (3) a reporting entity is the primary beneficiary of a VIE. Transition method: retrospective.	January 1, 2016	There were no changes to the consolidation conclusions.
New Accounting Standards Issued But Not Yet Effective
2016-17, Consolidation (Topic 810): Interest Held through Related Parties That Are under Common Control	This standard amends the evaluation of whether a reporting entity is the primary beneficiary of a VIE by amending how a reporting entity, that is a single decision maker of a VIE, treats indirect interests in that entity held through related parties that are under common control. Transition method: retrospectively.	January 1, 2017 Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.
2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory	This standard requires that an entity recognizes the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Transition method: modified retrospective method.	January 1, 2018 Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.
2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Receipts and Cash Payments (a consensus of the Emerging Issues Task Force)	This standard provides specific guidance on how certain cash transactions are presented and classified in the statement of cash flows. Transition method: retrospective method	January 1, 2018. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements, but do not anticipate a material impact.
2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments	This standard updates the impairment model for financial assets measured at amortized cost to an expected loss model rather than an incurred loss model. It also allows for the presentation of credit losses on available-for-sale debt securities as an allowance rather than a write down. Transition method: various.	January 1, 2020 Early adoption is permitted only as of January 1, 2019.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.
2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting	The standard simplifies the following aspects of accounting for share-based payment awards: accounting for income taxes, classification of excess tax benefits on the statement of cash flows, forfeitures, statutory tax withholding requirements, classification of awards as either equity or liabilities and classification of employee taxes paid on statement of cash flows when an employer withholds shares for tax-withholding purposes. Transition method: Various.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.
2016-06, Derivatives and Hedging (Topic 815) - Contingent Put and Call Options in Debt Instruments	This standard clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. When a call (put) option is contingently exercisable, an entity no longer has to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks. Transition method: a modified retrospective basis to existing debt instruments as of the effective date.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard, but do not anticipate a material impact on our consolidated financial statements.
2016-05, Derivatives and Hedging (Topic 815) - Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships	The standard clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not require de-designation of that hedging relationship provided that all other hedge accounting criteria (including those in paragraphs 815-20-35-14 through 35-18) continue to be met. Transition method: prospective or a modified retrospective basis.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard, but do not anticipate a material impact on our consolidated financial statements.

Accounting Standard	Description	Date of Adoption	Effect on the financial statements upon adoption
2016-02, Leases (Topic 842)	The standard creates Topic 842, Leases which supersedes Topic 840, Leases, and introduces a lessee model that brings substantially all leases onto the balance sheet while retaining most of the principles of the existing lessor model in U.S. GAAP and aligning many of those principles with ASC 606, Revenue from Contracts with Customers. Transition method: modified retrospective approach with certain practical expedients.	January 1, 2019. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.
2016-01, Financial Instruments - Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities	The standard significantly revises an entity’s accounting related to (1) the classification and measurement of investments in equity securities and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. Also, it amends certain disclosure requirements associated with the fair value of financial instruments. Transition: cumulative effect in Retained Earnings as of adoption or prospectively for equity investments without readily determinable fair value.	January 1, 2018. Limited early adoption permitted.	We are currently evaluating the impact of adopting the standard, but do not anticipate a material impact on our consolidated financial statements.
2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory	The standard replaces the current lower of cost or market test with a lower of cost or net realizable value test. Transition method: prospectively.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.
2014-09, 2016-08, 2016-10, 2016-12 Revenue from Contracts with Customers (Topic 606)	The Revenue from Contracts with Customers standard provides a single and comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing revenue recognition. The standard requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. The amendments to the standard provide further clarification on contract revenue recognition specifically related to the implementation of the principal versus agent evaluation, the identification of performance obligations, clarification on accounting for licenses of intellectual property, and allows for the election to account for shipping and handling activities performed after control of a good has been transferred to the customer as a fulfillment cost. Transition method: a full retrospective or modified retrospective approach.	January 1, 2018 (deferred by ASU No. 2015-14). Earlier application is permitted only as of January 1, 2017.	We are currently evaluating the impact of adopting the standard on our consolidated financial statements.

THE DAYTON POWER AND LIGHT COMPANY [Member]

Related Party Transaction [Line Items]

Schedule of New Accounting Pronouncements

The following table provides a brief description of recent accounting pronouncements that could have a material impact on our financial statements:

Accounting Standard	Description	Date of Adoption	Effect on the financial statements upon adoption
New Accounting Standards Adopted
2015-15, Interest - Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements	Given the absence of authoritative guidance within ASU 2015-03, this standard clarifies that the SEC Staff would not object to an entity presenting debt issuance costs related to line-of-credit arrangements as an asset that is subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. Transition method: retrospective.	January 1, 2016	Deferred financing costs related to lines-of-credit of approximately $0.7 million recorded within Other deferred assets were not reclassified.
2015-03, Interest - Imputation of Interest (Subtopic 835-30)	The standard simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the standard. Transition method: retrospective.	January 1, 2016	Deferred financing costs of approximately $1.8 million previously classified within Other prepayments and current assets and $4.5 million previously classified within Other deferred assets were reclassified to reduce the related debt liabilities.
2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis	The standard makes targeted amendments to the current consolidation guidance and ends the deferral granted to investment companies from applying the VIE guidance. The standard amends the evaluation of whether (1) fees paid to a decision-maker or service providers represent a variable interest, (2) a limited partnership or similar entity has the characteristics of a VIE and (3) a reporting entity is the primary beneficiary of a VIE. Transition method: retrospective.	January 1, 2016	There were no changes to the consolidation conclusions.
New Accounting Standards Issued But Not Yet Effective
2016-17, Consolidation (Topic 810): Interest Held through Related Parties That Are under Common Control	This standard amends the evaluation of whether a reporting entity is the primary beneficiary of a VIE by amending how a reporting entity, that is a single decision maker of a VIE, treats indirect interests in that entity held through related parties that are under common control. Transition method: retrospectively.	January 1, 2017 Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our financial statements.
2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory	This standard requires that an entity recognizes the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. Transition method: modified retrospective method.	January 1, 2018 Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our financial statements.
2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Receipts and Cash Payments (a consensus of the Emerging Issues Task Force)	This standard provides specific guidance on how certain cash transactions are presented and classified in the statement of cash flows. Transition method: retrospective method	January 1, 2018. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our financial statements but do not anticipate a material impact.

Accounting Standard	Description	Date of Adoption	Effect on the financial statements upon adoption
2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments	This standard updates the impairment model for financial assets measured at amortized cost to an expected loss model rather than an incurred loss model. It also allows for the presentation of credit losses on available-for-sale debt securities as an allowance rather than a write down. Transition method: various.	January 1, 2020 Early adoption is permitted only as of January 1, 2019.	We are currently evaluating the impact of adopting the standard on our financial statements.
2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting	The standard simplifies the following aspects of accounting for share-based payment awards: accounting for income taxes, classification of excess tax benefits on the statement of cash flows, forfeitures, statutory tax withholding requirements, classification of awards as either equity or liabilities and classification of employee taxes paid on statement of cash flows when an employer withholds shares for tax-withholding purposes. Transition method: Various.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our financial statements.
2016-06, Derivatives and Hedging (Topic 815) - Contingent Put and Call Options in Debt Instruments	This standard clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. When a call (put) option is contingently exercisable, an entity no longer has to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks. Transition method: a modified retrospective basis to existing debt instruments as of the effective date.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard, but do not anticipate a material impact on our financial statements.
2016-05, Derivatives and Hedging (Topic 815) - Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships	The standard clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not require de-designation of that hedging relationship provided that all other hedge accounting criteria (including those in paragraphs 815-20-35-14 through 35-18) continue to be met. Transition method: prospective or a modified retrospective basis.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard, but do not anticipate a material impact on our financial statements.
2016-02, Leases (Topic 842)	The standard creates Topic 842, Leases which supersedes Topic 840, Leases, and introduces a lessee model that brings substantially all leases onto the balance sheet while retaining most of the principles of the existing lessor model in U.S. GAAP and aligning many of those principles with ASC 606, Revenue from Contracts with Customers. Transition method: modified retrospective approach with certain practical expedients.	January 1, 2019. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our financial statements.
2016-01, Financial Instruments - Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities	The standard significantly revises an entity’s accounting related to (1) the classification and measurement of investments in equity securities and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. Also, it amends certain disclosure requirements associated with the fair value of financial instruments. Transition: cumulative effect in Retained Earnings as of adoption or prospectively for equity investments without readily determinable fair value.	January 1, 2018. Limited early adoption permitted.	We are currently evaluating the impact of adopting the standard, but do not anticipate a material impact on our financial statements.
2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory	The standard replaces the current lower of cost or market test with a lower of cost or net realizable value test. Transition method: prospectively.	January 1, 2017. Early adoption is permitted.	We are currently evaluating the impact of adopting the standard on our financial statements.

Accounting Standard	Description	Date of Adoption	Effect on the financial statements upon adoption
2014-09, 2016-08, 2016-10, 2016-12 Revenue from Contracts with Customers (Topic 606)	The Revenue from Contracts with Customers standard provides a single and comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing revenue recognition. The standard requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. The amendments to the standard provide further clarification on contract revenue recognition specifically related to the implementation of the principal versus agent evaluation, the identification of performance obligations, clarification on accounting for licenses of intellectual property, and allows for the election to account for shipping and handling activities performed after control of a good has been transferred to the customer as a fulfillment cost. Transition method: a full retrospective or modified retrospective approach.	January 1, 2018 (deferred by ASU No. 2015-14). Earlier application is permitted only as of January 1, 2017.	We are currently evaluating the impact of adopting the standard on our financial statements.