Debt and Credit Agreements - Summary of Bilateral Credit Agreements (Details) - Exelon Generation Co L L C [Member] - USD ($) $ in Millions	Feb. 09, 2022	Dec. 31, 2021
BilateralJan2013 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 100
BilateralJan2016 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		150
BilateralFeb2019 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
BilateralOct2019a [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		200
BilateralNov2019a [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		300
BilateralNov2019b [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		150
BilateralNov2019c [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
BilateralMay2020[Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 100
BilateralMay2020[Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200