Recently Issued Accounting Standards, Not Yet Adopted	12 Months Ended
Recently Issued Accounting Standards, Not Yet Adopted	Dec. 31, 2014
Recently Issued Accounting Standards, Not Yet Adopted	(4) RECENTLY ISSUED ACCOUNTING STANDARDS, NOT YET ADOPTED Revenue from Contracts with Customers (ASC 606) In May 2014, the FASB issued new recognition and disclosure requirements for revenue from contracts with customers, which supersedes the existing revenue recognition guidance. The new recognition requirements focus on when the customer obtains control of the goods or services, rather than the current risks and rewards model of recognition. The core principle of the new standard is that an entity will recognize revenue when it transfers goods or services to its customers in an amount that reflects the consideration an entity expects to be entitled to for those goods or services. The new disclosure requirements will include information intended to communicate the nature, amount, timing and any uncertainty of revenue and cash flows from applicable contracts, including any significant judgments and changes in judgments and assets recognized from the costs to obtain or fulfill a contract. Entities will generally be required to make more estimates and use more judgment under the new standard. The new requirements are effective for PHI beginning January 1, 2017, and may be implemented either retrospectively for all periods presented, or as a cumulative-effect adjustment as of January 1, 2017. Early adoption is not permitted. PHI is currently evaluating the potential impact of this new guidance on its consolidated financial statements and which implementation approach to select. Business Combinations (ASC 805) In November 2014, the FASB issued new recognition and disclosure requirements related to pushdown accounting. The new recognition requirements grant an acquired entity (or its subsidiaries) the option to elect whether and when a new accounting and reporting basis (pushdown accounting) will be applied when an acquirer obtains control of the acquired entity. This election may be made by the acquired entity (or its subsidiaries) for future change-in-control events or for its most recent change-in-control event, and the acquired entity will be required to determine whether pushdown accounting will be applied in the reporting period in which the change-in-control event occurs or in a subsequent reporting period. The new required disclosures include information that enables financial statement users to evaluate the effects of pushdown accounting. Disclosures are required to be made in the period in which pushdown accounting is applied and are expected to include both qualitative and quantitative information. The new recognition and disclosure requirements became effective on a prospective basis on November 18, 2014. PHI currently anticipates it may be affected by the new guidance if its Merger with Exelon closes.
Delmarva Power & Light Co/De [Member]
Recently Issued Accounting Standards, Not Yet Adopted	(4) RECENTLY ISSUED ACCOUNTING STANDARDS, NOT YET ADOPTED Revenue from Contracts with Customers (ASC 606) In May 2014, the FASB issued new recognition and disclosure requirements for revenue from contracts with customers, which supersedes the existing revenue recognition guidance. The new recognition requirements focus on when the customer obtains control of the goods or services, rather than the current risks and rewards model of recognition. The core principle of the new standard is that an entity will recognize revenue when it transfers goods or services to its customers in an amount that reflects the consideration an entity expects to be entitled to for those goods or services. The new disclosure requirements will include information intended to communicate the nature, amount, timing and any uncertainty of revenue and cash flows from applicable contracts, including any significant judgments and changes in judgments and assets recognized from the costs to obtain or fulfill a contract. Entities will generally be required to make more estimates and use more judgment under the new standard. The new requirements are effective for DPL beginning January 1, 2017, and may be implemented either retrospectively for all periods presented, or as a cumulative-effect adjustment as of January 1, 2017. Early adoption is not permitted. DPL is currently evaluating the potential impact of this new guidance on its financial statements and which implementation approach to select. Business Combinations (ASC 805) In November 2014, the FASB issued new recognition and disclosure requirements related to pushdown accounting. The new recognition requirements grant an acquired entity (or its subsidiaries) the option to elect whether and when a new accounting and reporting basis (pushdown accounting) will be applied when an acquirer obtains control of the acquired entity. This election may be made by the acquired entity (or its subsidiaries) for future change-in-control events or for its most recent change-in-control event, and the acquired entity will be required to determine whether pushdown accounting will be applied in the reporting period in which the change-in-control event occurs or in a subsequent reporting period. The new required disclosures include information that enables financial statement users to evaluate the effects of pushdown accounting. Disclosures are required to be made in the period in which pushdown accounting is applied and are expected to include both qualitative and quantitative information. The new recognition and disclosure requirements became effective on a prospective basis on November 18, 2014.
Potomac Electric Power Co [Member]
Recently Issued Accounting Standards, Not Yet Adopted	(4) RECENTLY ISSUED ACCOUNTING STANDARDS, NOT YET ADOPTED Revenue from Contracts with Customers (ASC 606) In May 2014, the FASB issued new recognition and disclosure requirements for revenue from contracts with customers, which supersedes the existing revenue recognition guidance. The new recognition requirements focus on when the customer obtains control of the goods or services, rather than the current risks and rewards model of recognition. The core principle of the new standard is that an entity will recognize revenue when it transfers goods or services to its customers in an amount that reflects the consideration an entity expects to be entitled to for those goods or services. The new disclosure requirements will include information intended to communicate the nature, amount, timing and any uncertainty of revenue and cash flows from applicable contracts, including any significant judgments and changes in judgments and assets recognized from the costs to obtain or fulfill a contract. Entities will generally be required to make more estimates and use more judgment under the new standard. The new requirements are effective for Pepco beginning January 1, 2017, and may be implemented either retrospectively for all periods presented, or as a cumulative-effect adjustment as of January 1, 2017. Early adoption is not permitted. Pepco is currently evaluating the potential impact of this new guidance on its financial statements and which implementation approach to select. Business Combinations (ASC 805) In November 2014, the FASB issued new recognition and disclosure requirements related to pushdown accounting. The new recognition requirements grant an acquired entity (or its subsidiaries) the option to elect whether and when a new accounting and reporting basis (pushdown accounting) will be applied when an acquirer obtains control of the acquired entity. This election may be made by the acquired entity (or its subsidiaries) for future change-in-control events or for its most recent change-in-control event, and the acquired entity will be required to determine whether pushdown accounting will be applied in the reporting period in which the change-in-control event occurs or in a subsequent reporting period. The new required disclosures include information that enables financial statement users to evaluate the effects of pushdown accounting. Disclosures are required to be made in the period in which pushdown accounting is applied and are expected to include both qualitative and quantitative information. The new recognition and disclosure requirements became effective on a prospective basis on November 18, 2014.
Atlantic City Electric Co [Member]
Recently Issued Accounting Standards, Not Yet Adopted	(4) RECENTLY ISSUED ACCOUNTING STANDARDS, NOT YET ADOPTED Revenue from Contracts with Customers (ASC 606) In May 2014, the FASB issued new recognition and disclosure requirements for revenue from contracts with customers, which supersedes the existing revenue recognition guidance. The new recognition requirements focus on when the customer obtains control of the goods or services, rather than the current risks and rewards model of recognition. The core principle of the new standard is that an entity will recognize revenue when it transfers goods or services to its customers in an amount that reflects the consideration an entity expects to be entitled to for those goods or services. The new disclosure requirements will include information intended to communicate the nature, amount, timing and any uncertainty of revenue and cash flows from applicable contracts, including any significant judgments and changes in judgments and assets recognized from the costs to obtain or fulfill a contract. Entities will generally be required to make more estimates and use more judgment under the new standard. The new requirements are effective for ACE beginning January 1, 2017, and may be implemented either retrospectively for all periods presented, or as a cumulative-effect adjustment as of January 1, 2017. Early adoption is not permitted. ACE is currently evaluating the potential impact of this new guidance on its consolidated financial statements and which implementation approach to select. Business Combinations (ASC 805) In November 2014, the FASB issued new recognition and disclosure requirements related to pushdown accounting. The new recognition requirements grant an acquired entity (or its subsidiaries) the option to elect whether and when a new accounting and reporting basis (pushdown accounting) will be applied when an acquirer obtains control of the acquired entity. This election may be made by the acquired entity (or its subsidiaries) for future change-in-control events or for its most recent change-in-control event, and the acquired entity will be required to determine whether pushdown accounting will be applied in the reporting period in which the change-in-control event occurs or in a subsequent reporting period. The new required disclosures include information that enables financial statement users to evaluate the effects of pushdown accounting. Disclosures are required to be made in the period in which pushdown accounting is applied and are expected to include both qualitative and quantitative information. The new recognition and disclosure requirements became effective on a prospective basis on November 18, 2014.