Mergers, Acquisitions, and Dispositions	3 Months Ended
Mar. 31, 2015
Business Combinations [Abstract]
Mergers, Acquisitions and Dispositions	Mergers, Acquisitions, and Dispositions Proposed Merger with Pepco Holdings, Inc. (Exelon) Description of Transaction On April 29, 2014, Exelon and Pepco Holdings, Inc. (PHI) signed an agreement and plan of merger (as subsequently amended and restated as of July 18, 2014, the Merger Agreement) to combine the two companies in an all cash transaction. The resulting company will retain the Exelon name and be headquartered in Chicago. Under the Merger Agreement, PHI’s shareholders will receive $27.25 of cash in exchange for each share of PHI common stock. In connection with the Merger Agreement, Exelon entered into a subscription agreement under which it has purchased $144 million of a new class of nonvoting, nonconvertible and nontransferable preferred securities of PHI as of March 31, 2015, with additional investments of $18 million to be made quarterly up to a maximum aggregate investment of $180 million. The preferred securities are included in Other non-current assets on Exelon’s Consolidated Balance Sheet. PHI has the right to redeem the preferred securities at its option for the purchase price paid plus accrued dividends, if any. Exelon expects total cash required to fund the acquisition of common stock and preferred securities plus other related acquisition costs to total approximately $7.2 billion. As part of the applications for approval of the merger, under pending or final settlements reached to date, as well as other filings, Exelon and PHI have proposed a package to the PHI utilities’ respective customers, providing for direct investment in excess of approximately $300 million with the actual amount and timing of any related payments dependent upon settlement discussions in merger regulatory approval proceedings and the terms of regulatory orders approving the merger. On October 9, 2014, PHI and Exelon each received a request for additional information from the DOJ. The request had the effect of extending the DOJ review period until 30 days after PHI and Exelon each has certified that it had substantially complied with the request. On November 21, 2014, Exelon and PHI each certified that it had substantially complied with the request. Accordingly, the HSR Act waiting period expired on December 22, 2014, and the HSR Act no longer precludes completion of the merger. Although the DOJ allowed the waiting period under the HSR Act to expire without taking any action with respect to the merger, the DOJ has not advised Exelon or PHI that it has concluded its investigation. Exelon and PHI have cooperated with the DOJ regarding the proposed merger. To date, the PHI stockholders, the Virginia State Corporation Commission, the New Jersey Board of Public Utilities (NJBPU) and the FERC have approved the merger of PHI and Exelon. The Federal Communications Commission has also approved the transfer of certain PHI communications licenses. On February 13, 2015, Exelon and PHI announced that they had reached a settlement agreement in the proceeding before the Delaware Public Service Commission (DPSC) to review the proposed merger. The settlement, which was amended on April 7, 2015 and is subject to the approval of the DPSC, was signed and filed by Exelon, PHI, Delmarva Power & Light Company (DPL), the DPSC Staff, the Delaware Public Advocate, the Delaware Department of Natural Resources and Environment Control, the Delaware Sustainable Energy Utility, the Mid-Atlantic Renewable Energy Coalition and the Clean Air Council. As part of this settlement, Exelon and PHI have proposed a package of benefits to DPL customers and the state of Delaware including the establishment of customer rate credits of $40 million for DPL customers in Delaware, $2 million of funding for energy efficiency programs for DPL low income customers, and $2 million of funding for workforce development. On March 17, 2015, Exelon and PHI announced that they had reached a settlement agreement with Montgomery and Prince George’s Counties in the proceeding before the MDPSC to review the proposed merger. The settlement, which is subject to the approval of the MDPSC, was signed and filed by Exelon, PHI, Montgomery County, Prince George’s County, the National Consumer Law Center, National Housing Trust, Maryland Affordable Housing Coalition, the Housing Association of Nonprofit Developers and a consortium of recreational trail advocacy organizations led by the Mid-Atlantic Off-Road Enthusiasts. As part of this settlement, Exelon and PHI have proposed a package of benefits to Potomac Electric Power Company (Pepco) and DPL customers and the state of Maryland including the establishment of a customer investment fund of $94.4 million for utility customers in Maryland. A portion of the customer investment fund, representing approximately $36.8 million, will provide bill credits to Pepco and DPL customers in Maryland, with the remaining $57.6 million funding energy-efficiency programs, including programs targeted to help low income customers lower their energy bills. Exelon also agreed to establish a Green Sustainability Fund (GSF) of $50 million to be allocated across the service territories of Pepco, DPL and ACE, with $19.8 million allocated to Maryland. The GSF will be allocated within each state to state and local “green banks” and similar sponsoring organizations to make loans to finance public and private investment in renewable energy, microgrids, and other developing energy technologies. Loans made by sponsoring organizations from the GSF must mature within 20 years following the merger closing. At the end of that 20 year period, principal payments received by the sponsoring organizations must be returned to Exelon, but Exelon’s recovery of the entire GSF is not assured. In the settlement, Exelon also agreed to provide $4 million in funding for workforce development in Maryland and made various other commitments, including a commitment to develop 15 MW of commercial solar projects in Maryland. In a related agreement with Prince George’s County, Exelon agreed to develop an additional 5 MW of solar generation in Maryland, the output of which will be delivered to Prince George’s County under a 30-year PPA at no cost to the county for the first 15 years and at market pricing for the second 15 years. This agreement also requires Prince George’s County to purchase substantially all of its requirements for electricity and natural gas from an Exelon affiliate for a period of 15 years, unless the Exelon affiliate is not the lowest bidder. On March 10, 2015, Exelon and PHI announced that they had reached a settlement agreement with the Alliance for Solar Choice, a group of solar developers, in the proceeding before the MDPSC. The settlement, which is subject to the approval of the MDPSC, provides for enhancements to the interconnection process for behind-the-meter distributed generation and storage projects. Exelon and PHI continue to expect the merger to be completed late in the second or third quarter of 2015. Exelon has been named in suits filed in the Delaware Chancery Court alleging that individual directors of PHI breached their fiduciary duties by entering into the proposed merger transaction and Exelon aided and abetted the individual directors’ breaches. The suits seek to enjoin PHI from completing the merger or seek rescission of the merger if completed. In addition, they also seek unspecified damages and costs. Exelon was also named in a federal court suit making similar claims. In September 2014, the parties reached a proposed settlement that would resolve all claims, which is subject to court approval. Final court approval of the proposed settlement is not anticipated until approximately 90 days after merger close. Exelon does not believe these suits will impact the completion of the transaction, and they are not expected to have a material impact on Exelon’s results of operations. Including 2014 and through March 31, 2015, Exelon has incurred approximately $289 million of expense associated with the proposed merger, primarily $69 million related to acquisition and integration costs and $220 million of costs incurred to finance the transaction. The Merger Agreement also provides for termination rights for both parties. Under certain circumstances, if the Merger Agreement is terminated, PHI may be required to pay Exelon a termination fee ranging from $259 million to $293 million plus certain expenses. If the Merger Agreement is terminated due to a regulatory failure, Exelon may be required to pay PHI a termination fee equal to the amount of purchased nonvoting preferred securities of PHI described above, through the redemption by PHI of the outstanding nonvoting preferred securities for no consideration other than the nominal par value of the stock, plus certain expenses. Merger Financing Exelon intends to fund the all-cash transaction using a combination of approximately $3.5 billion of debt, up to $1.0 billion in cash from asset sales primarily at Generation, and the remainder through issuance of equity (including mandatory convertible securities). On June 11, 2014, Exelon marketed an equity offering of 57.5 million shares of its common stock at a public offering price of $35 per share in connection with forward sales agreements and $1.2 billion of junior subordinated notes in the form of 23 million equity units. In addition, Exelon signed a 364-day $7.2 billion senior unsecured bridge credit facility to support the contemplated transaction and provide flexibility for timing of permanent financing, which has subsequently been reduced to a $3.2 billion facility as a result of the execution of the equity issuance and the net after-tax cash proceeds from generating asset divestitures during the second half of 2014. See Note 9 — Debt and Credit Agreements and Note 15 — Common Stock for more information. Acquisitions (Exelon and Generation) Acquisition of Integrys Energy Group, Inc. (Exelon and Generation) On November 1, 2014, Generation acquired the competitive retail electric and natural gas business activities of Integrys Energy Group, Inc. through the purchase of all of the stock of its wholly owned subsidiary, Integrys Energy Services, Inc. (Integrys) for a purchase price of $332 million, including net working capital. As of March 31, 2015, Generation had remitted $319 million to Integrys Energy Group, Inc. and the remaining balance of $13 million is included in Other current liabilities on Exelon's and Generation's Consolidated Balance Sheets. The remaining balance was paid on April 17, 2015. Asset Divestitures (Exelon and Generation) On January 21, 2015, Generation closed on the sale of the Quail Run generating facility. Including the sale of the Quail Run generating facility, Generation has sold generating assets for total pre-tax proceeds of $1.8 billion (after-tax proceeds of $1.4 billion) which are expected to be used primarily to finance a portion of the acquisition of PHI. At March 31, 2015, assets of $1 million related to property, plant and equipment are recorded as Assets held for sale on Exelon’s and Generation’s Consolidated Balance Sheet.

Mergers, Acquisitions, and Dispositions

Proposed Merger with Pepco Holdings, Inc. (Exelon)

Description of Transaction

On April 29, 2014, Exelon and Pepco Holdings, Inc. (PHI) signed an agreement and plan of merger (as subsequently amended and restated as of July 18, 2014, the Merger Agreement) to combine the two companies in an all cash transaction. The resulting company will retain the Exelon name and be headquartered in Chicago. Under the Merger Agreement, PHI’s shareholders will receive $27.25 of cash in exchange for each share of PHI common stock. In connection with the Merger Agreement, Exelon entered into a subscription agreement under which it has purchased $144 million of a new class of nonvoting, nonconvertible and nontransferable preferred securities of PHI as of March 31, 2015, with additional investments of $18 million to be made quarterly up to a maximum aggregate investment of $180 million. The preferred securities are included in Other non-current assets on Exelon’s Consolidated Balance Sheet. PHI has the right to redeem the preferred securities at its option for the purchase price paid plus accrued dividends, if any. Exelon expects total cash required to fund the acquisition of common stock and preferred securities plus other related acquisition costs to total approximately $7.2 billion. As part of the applications for approval of the merger, under pending or final settlements reached to date, as well as other filings, Exelon and PHI have proposed a package to the PHI utilities’ respective customers, providing for direct investment in excess of approximately $300 million with the actual amount and timing of any related payments dependent upon settlement discussions in merger regulatory approval proceedings and the terms of regulatory orders approving the merger.

On October 9, 2014, PHI and Exelon each received a request for additional information from the DOJ. The request had the effect of extending the DOJ review period until 30 days after PHI and Exelon each has certified that it had substantially complied with the request. On November 21, 2014, Exelon and PHI each certified that it had substantially complied with the request. Accordingly, the HSR Act waiting period expired on December 22, 2014, and the HSR Act no longer precludes completion of the merger. Although the DOJ allowed the waiting period under the HSR Act to expire without taking any action with respect to the merger, the DOJ has not advised Exelon or PHI that it has concluded its investigation. Exelon and PHI have cooperated with the DOJ regarding the proposed merger.

To date, the PHI stockholders, the Virginia State Corporation Commission, the New Jersey Board of Public Utilities (NJBPU) and the FERC have approved the merger of PHI and Exelon. The Federal Communications Commission has also approved the transfer of certain PHI communications licenses.

On February 13, 2015, Exelon and PHI announced that they had reached a settlement agreement in the proceeding before the Delaware Public Service Commission (DPSC) to review the proposed merger. The settlement, which was amended on April 7, 2015 and is subject to the approval of the DPSC, was signed and filed by Exelon, PHI, Delmarva Power & Light Company (DPL), the DPSC Staff, the Delaware Public Advocate, the Delaware Department of Natural Resources and Environment Control, the Delaware Sustainable Energy Utility, the Mid-Atlantic Renewable Energy Coalition and the Clean Air Council. As part of this settlement, Exelon and PHI have proposed a package of benefits to DPL customers and the state of Delaware including the establishment of customer rate credits of $40 million for DPL customers in Delaware, $2 million of funding for energy efficiency programs for DPL low income customers, and $2 million of funding for workforce development.

On March 17, 2015, Exelon and PHI announced that they had reached a settlement agreement with Montgomery and Prince George’s Counties in the proceeding before the MDPSC to review the proposed merger. The settlement, which is subject to the approval of the MDPSC, was signed and filed by Exelon, PHI, Montgomery County, Prince George’s County, the National Consumer Law Center, National Housing Trust, Maryland Affordable Housing Coalition, the Housing Association of Nonprofit Developers and a consortium of recreational trail advocacy organizations led by the Mid-Atlantic Off-Road Enthusiasts. As part of this settlement, Exelon and PHI have proposed a package of benefits to Potomac Electric Power Company (Pepco) and DPL customers and the state of Maryland including the establishment of a customer investment fund of $94.4 million for utility customers in Maryland. A portion of the customer investment fund, representing approximately $36.8 million, will provide bill credits to Pepco and DPL customers in Maryland, with the remaining $57.6 million funding energy-efficiency programs, including programs targeted to help low income customers lower their energy bills. Exelon also agreed to establish a Green Sustainability Fund (GSF) of $50 million to be allocated across the service territories of Pepco, DPL and ACE, with $19.8 million allocated to Maryland. The GSF will be allocated within each state to state and local “green banks” and similar sponsoring organizations to make loans to finance public and private investment in renewable energy, microgrids, and other developing energy technologies. Loans made by sponsoring organizations from the GSF must mature within 20 years following the merger closing. At the end of that 20 year period, principal payments received by the sponsoring organizations must be returned to Exelon, but Exelon’s recovery of the entire GSF is not assured. In the settlement, Exelon also agreed to provide $4 million in funding for workforce development in Maryland and made various other commitments, including a commitment to develop 15 MW of commercial solar projects in Maryland. In a related agreement with Prince George’s County, Exelon agreed to develop an additional 5 MW of solar generation in Maryland, the output of which will be delivered to Prince George’s County under a 30-year PPA at no cost to the county for the first 15 years and at market pricing for the second 15 years. This agreement also requires Prince George’s County to purchase substantially all of its requirements for electricity and natural gas from an Exelon affiliate for a period of 15 years, unless the Exelon affiliate is not the lowest bidder.

On March 10, 2015, Exelon and PHI announced that they had reached a settlement agreement with the Alliance for Solar Choice, a group of solar developers, in the proceeding before the MDPSC. The settlement, which is subject to the approval of the MDPSC, provides for enhancements to the interconnection process for behind-the-meter distributed generation and storage projects.

Exelon and PHI continue to expect the merger to be completed late in the second or third quarter of 2015.

Exelon has been named in suits filed in the Delaware Chancery Court alleging that individual directors of PHI breached their fiduciary duties by entering into the proposed merger transaction and Exelon aided and abetted the individual directors’ breaches. The suits seek to enjoin PHI from completing the merger or seek rescission of the merger if completed. In addition, they also seek unspecified damages and costs. Exelon was also named in a federal court suit making similar claims. In September 2014, the parties reached a proposed settlement that would resolve all claims, which is subject to court approval. Final court approval of the proposed settlement is not anticipated until approximately 90 days after merger close. Exelon does not believe these suits will impact the completion of the transaction, and they are not expected to have a material impact on Exelon’s results of operations.

Including 2014 and through March 31, 2015, Exelon has incurred approximately $289 million of expense associated with the proposed merger, primarily $69 million related to acquisition and integration costs and $220 million of costs incurred to finance the transaction.

The Merger Agreement also provides for termination rights for both parties. Under certain circumstances, if the Merger Agreement is terminated, PHI may be required to pay Exelon a termination fee ranging from $259 million to $293 million plus certain expenses. If the Merger Agreement is terminated due to a regulatory failure, Exelon may be required to pay PHI a termination fee equal to the amount of purchased nonvoting preferred securities of PHI described above, through the redemption by PHI of the outstanding nonvoting preferred securities for no consideration other than the nominal par value of the stock, plus certain expenses.

Merger Financing

Exelon intends to fund the all-cash transaction using a combination of approximately $3.5 billion of debt, up to $1.0 billion in cash from asset sales primarily at Generation, and the remainder through issuance of equity (including mandatory convertible securities). On June 11, 2014, Exelon marketed an equity offering of 57.5 million shares of its common stock at a public offering price of $35 per share in connection with forward sales agreements and $1.2 billion of junior subordinated notes in the form of 23 million equity units. In addition, Exelon signed a 364-day $7.2 billion senior unsecured bridge credit facility to support the contemplated transaction and provide flexibility for timing of permanent financing, which has subsequently been reduced to a $3.2 billion facility as a result of the execution of the equity issuance and the net after-tax cash proceeds from generating asset divestitures during the second half of 2014. See Note 9 — Debt and Credit Agreements and Note 15 — Common Stock for more information.

Acquisitions (Exelon and Generation)

Acquisition of Integrys Energy Group, Inc. (Exelon and Generation)

On November 1, 2014, Generation acquired the competitive retail electric and natural gas business activities of Integrys Energy Group, Inc. through the purchase of all of the stock of its wholly owned subsidiary, Integrys Energy Services, Inc. (Integrys) for a purchase price of $332 million, including net working capital. As of March 31, 2015, Generation had remitted $319 million to Integrys Energy Group, Inc. and the remaining balance of $13 million is included in Other current liabilities on Exelon's and Generation's Consolidated Balance Sheets. The remaining balance was paid on April 17, 2015.

Asset Divestitures (Exelon and Generation)

On January 21, 2015, Generation closed on the sale of the Quail Run generating facility. Including the sale of the Quail Run generating facility, Generation has sold generating assets for total pre-tax proceeds of $1.8 billion (after-tax proceeds of $1.4 billion) which are expected to be used primarily to finance a portion of the acquisition of PHI.

At March 31, 2015, assets of $1 million related to property, plant and equipment are recorded as Assets held for sale on Exelon’s and Generation’s Consolidated Balance Sheet.