XML 128 R84.htm IDEA: XBRL DOCUMENT v3.21.1
Fair Value of Financial Assets and Liabilities - Fair Value Assets Liabilities Measured On Recurring Basis Unobservable Input Reconciliation (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Fair Value, Inputs, Level 3 [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance $ 660 $ 1,068
Total realized / unrealized gains (losses)    
Included in net income (276) 10
Included in noncurrent payables to affiliates 0 0
Included in regulatory assets 7 (14)
Change in collateral (57) 1
Purchases, sales, issuances and settlements    
Purchases 109 42
Sales 1 (22)
Settlements (20) (14)
Transfers into Level 3   2
Transfers out of Level 3 2 15
Ending Balance 426 1,088
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) (147) 187
Fair Value, Inputs, Level 3 [Member] | Consolidation, Eliminations [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 0 0
Total realized / unrealized gains (losses)    
Included in net income 0 0
Included in noncurrent payables to affiliates (1) 1
Included in regulatory assets 1 (1)
Change in collateral 0 0
Purchases, sales, issuances and settlements    
Purchases 0 0
Sales 0 0
Settlements 0 0
Transfers into Level 3   0
Transfers out of Level 3 0 0
Ending Balance 0 0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) 0 0
Exelon Generation Co L L C [Member]    
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Abstract]    
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings 129 177
Exelon Generation Co L L C [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 927 1,328
Total realized / unrealized gains (losses)    
Included in net income (277) 9
Included in noncurrent payables to affiliates 1 (1)
Included in regulatory assets 0 0
Change in collateral (57) 1
Purchases, sales, issuances and settlements    
Purchases 109 42
Sales 1 (22)
Settlements (20) (14)
Transfers into Level 3   2
Transfers out of Level 3 2 15
Ending Balance 686 1,360
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) (148) 186
Exelon Generation Co L L C [Member] | Fair Value, Inputs, Level 3 [Member] | Nuclear Decommissioning Trust Fund Investments [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 497 511
Total realized / unrealized gains (losses)    
Included in net income 1 (1)
Included in noncurrent payables to affiliates 1 (1)
Included in regulatory assets 0 0
Change in collateral 0 0
Purchases, sales, issuances and settlements    
Purchases 0 3
Sales 0 0
Settlements (20) (14)
Transfers into Level 3   0
Transfers out of Level 3 0 0
Ending Balance 479 498
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) 1 (1)
Exelon Generation Co L L C [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 430 817
Total realized / unrealized gains (losses)    
Included in net income (278) 10
Included in noncurrent payables to affiliates 0 0
Included in regulatory assets 0 0
Change in collateral (57) 1
Purchases, sales, issuances and settlements    
Purchases 109 39
Sales 1 (22)
Settlements 0 0
Transfers into Level 3   2
Transfers out of Level 3 2 15
Ending Balance 207 862
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) (149) 187
Commonwealth Edison Co [Member] | Derivative [Member] | Interest Rate Swap [Member]    
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Abstract]    
Realized Investment Gains (Losses) 8 10
Commonwealth Edison Co [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance (301) (301)
Total realized / unrealized gains (losses)    
Included in net income 0 0
Included in noncurrent payables to affiliates 0 0
Included in regulatory assets 6 (13)
Change in collateral 0 0
Purchases, sales, issuances and settlements    
Purchases 0 0
Sales 0 0
Settlements 0 0
Transfers into Level 3   0
Transfers out of Level 3 0 0
Ending Balance (295) (314)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) 0 0
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Abstract]    
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease) (2) (23)
Pepco Holdings LLC [Member] | Fair Value, Inputs, Level 3 [Member] | 6311 Life Insurance [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 34 41
Total realized / unrealized gains (losses)    
Included in net income 1 1
Included in noncurrent payables to affiliates 0 0
Included in regulatory assets 0 0
Change in collateral 0 0
Purchases, sales, issuances and settlements    
Purchases 0 0
Sales 0 0
Settlements 0 0
Transfers into Level 3   0
Transfers out of Level 3 0 0
Ending Balance 35 42
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) 1 1
Potomac Electric Power Company [Member] | Fair Value, Inputs, Level 3 [Member] | 6311 Life Insurance [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Beginning Balance 34 41
Total realized / unrealized gains (losses)    
Included in net income 1 1
Included in noncurrent payables to affiliates 0 0
Included in regulatory assets 0 0
Change in collateral 0 0
Purchases, sales, issuances and settlements    
Purchases 0 0
Sales 0 0
Settlements 0 0
Transfers into Level 3   0
Transfers out of Level 3 0 0
Ending Balance 35 42
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) $ 1 $ 1