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Fair value as of the balance sheet date of cash and non-cash collateral held for loan securities

+ References

No definition available.

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- Details

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- Definition

The after-tax charge to income tax expense to reverse the deferred tax assets previously established for government-subsidized retiree health care costs. In March 2010, the Patient Protection and Affordable Care Act, as modified by the Health Care and Education Reconciliation Act, was enacted into law, which eliminated the deductibility, for Federal income tax purposes, of retiree health care costs to the extent an employer's postretirement health care plan received Federal subsidies.

+ References

No definition available.

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- Definition

The fair value of plan assets as a percentage of the benefit obligation.

+ References

No definition available.

+ Details

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- Definition

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the other postretirement benefit plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

+ References

No definition available.

+ Details

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- Definition

The excise tax rate that will be charged on premiums paid over a prescribed threshold on certain high-cost benefit plans beginning in 2018 resulting from the 2010 Health Care Reform Acts.

+ References

No definition available.

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- Definition

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the non-qualified pension plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

+ References

No definition available.

+ Details

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- Definition

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the qualified pension plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

+ References

No definition available.

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- Definition

Amount of the effect of the government subsidy for prescription drug benefits on the measurement of net periodic postretirement benefit cost. That effect includes (1) any amortization of the actuarial experience gain, (2) the reduction in current period service cost due to the subsidy, and (3) the resulting reduction in interest cost on the accumulated postretirement benefit obligation as a result of the subsidy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 60

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39689-114964

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- Definition

Amount, after the effects of master netting arrangements, of securities loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (c)

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-Name Accounting Standards Codification

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-SubTopic 20

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-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

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-Name Accounting Standards Codification

-Topic 940

-SubTopic 405

-Section 55

-Paragraph 1

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Retirement Benefits - Additional (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended				12 Months Ended				3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended
	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013 Projected Benefit Obligation In Excess Of Plan Assets [Member]	Dec. 31, 2012 Projected Benefit Obligation In Excess Of Plan Assets [Member]	Dec. 31, 2013 Accumulated Benefit Obligation In Excess Of Plan Assets [Member]	Dec. 31, 2012 Accumulated Benefit Obligation In Excess Of Plan Assets [Member]	Mar. 31, 2010 Exelon Generation Co L L C [Member]	Dec. 31, 2014 Exelon Generation Co L L C [Member]	Mar. 31, 2010 Commonwealth Edison Co [Member]	Dec. 31, 2014 Commonwealth Edison Co [Member]	Mar. 31, 2010 PECO Energy Co [Member]	Dec. 31, 2014 PECO Energy Co [Member]	Mar. 31, 2010 Baltimore Gas and Electric Company [Member]	Dec. 31, 2014 Baltimore Gas and Electric Company [Member]	Dec. 31, 2012 Baltimore Gas and Electric Company [Member]	Dec. 31, 2011 Baltimore Gas and Electric Company [Member]
Benefit Obligation and Plan Assets, and Funded Status [Abstract]
Funded status of the pension and other postretirement benefit obligations						88.00%	80.00%	93.00%	85.00%
Healthcare Reform Legislation Impact [Abstract]
After-tax charge to income tax expense as a result of health care reform legislation	$ 65									$ 24		$ 11		$ 9		$ 3
Excise tax on certain high-cost benefit plans					40.00%
Components Of Net Periodic Benefit Costs [Abstract]
Effect of federal subsidy on net periodic postretirement benefit costs under the Prescription Drug Act		(17)	28
Defined Benefit Plan Contributions [Abstract]
Expected qualified pension plan contributions				264							118		119		11
Expected non-qualified pension plan contributions				12							5		1				1
Expected other postretirement benefit plan contributions				430							168		197		19		17	4	13
Securities Lending Program [Abstract]
Fair value of securities on loan					17
Fair value of cash and non-cash collateral received for loan securities					$ 17