CENG Preferred Distribution Return

No definition available.

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- Definition

Percentage of ownership interest in certain nonconsolidated VIEs where none of the equity holders consolidate these VIEs.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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- Definition

Amount of tangible or intangible assets, including a business or subsidiary of the acquirer transferred by the entity to the former owners of the acquiree. Excludes cash.

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Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.

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No definition available.

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For an unclassified balance sheet, amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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No definition available.

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Cash outflow to owners or shareholders, excluding ordinary dividends. Includes special dividends.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Mergers, Acquisitions and Dispositions - Acquisitions Narrative (Details) - USD ($) $ in Millions				12 Months Ended
	Apr. 04, 2018	Mar. 31, 2017	Apr. 01, 2014	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross				$ 41	$ 154	$ 208
Business Combination, Bargain Purchase, Gain Recognized, Amount				0	0	233
Fitzpatrick [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 289
Business Combination, Consideration Transferred, Other		179
Business Combination, Bargain Purchase, Gain Recognized, Amount						233
Business Combination, Integration Related Costs						57
Fitzpatrick [Member] \| Cash and Cash Equivalents [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		110
Handley [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 62
Exelon Generation Co L L C [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross				41	154	208
Business Combination, Bargain Purchase, Gain Recognized, Amount				$ 0	$ 0	233
Exelon Generation Co L L C [Member] \| Fitzpatrick [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		289
Business Combination, Consideration Transferred, Other		179
Business Combination, Bargain Purchase, Gain Recognized, Amount						233
Business Combination, Integration Related Costs						$ 57
Exelon Generation Co L L C [Member] \| Fitzpatrick [Member] \| Cash and Cash Equivalents [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 110
Exelon Generation Co L L C [Member] \| Handley [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 62
CENG [Member]
Business Acquisition [Line Items]
Ownership Percentage Of Consolidated Variable Interest Entities				50.01%
Payments of Capital Distribution			$ 400
Due from Affiliates			400	$ 571
CENG Preferred Distribution Return				8.50%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				49.99%
CENG [Member] \| Exelon Generation Co L L C [Member]
Business Acquisition [Line Items]
Ownership Percentage Of Consolidated Variable Interest Entities				50.01%
Payments of Capital Distribution			400
Due from Affiliates			$ 400	$ 571
CENG Preferred Distribution Return				8.50%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				49.99%
Nine Mile Point [Member]
Business Acquisition [Line Items]
Ownership Percentage Of Consolidated Variable Interest Entities				82.00%
Nine Mile Point [Member] \| Exelon Generation Co L L C [Member]
Business Acquisition [Line Items]
Ownership Percentage Of Consolidated Variable Interest Entities				82.00%