XML 77 R91.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Fair Value Measurements - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Nov. 12, 2019
Sep. 30, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Decommissioning fund investments $ 0     $ 790
Investment excludes receivables, payables and accrued income (16)     4
Noncurrent liabilities - held for sale (Note 10) 691     0
Investments - held for sale (Note 10) 882     0
Investments not required to be disclosed $ 299     $ 253
NUG contracts        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Period of future observable data to determine contract price 2 years      
Nuclear Plant Matters        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Decommissioning fund investments $ 882      
Financial Guarantee | Nuclear Plant Matters | JCP&L, ME, PN and GPUN        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Decommissioning fund investments     $ 900  
Ownership interest   25.00%    
TMI-2        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Noncurrent liabilities - held for sale (Note 10) $ 691