XML 69 R56.htm IDEA: XBRL DOCUMENT v3.23.3
Significant Accounting Policies (Schedule of Supplemental Cash Flow Information) (Parenthetical) (Detail) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Schedule Of Supplemental Cash Flow Information [Line Items]    
Financing leases $ 51 $ 29
Operating Leases 243 100
Virginia Electric and Power Company    
Schedule Of Supplemental Cash Flow Information [Line Items]    
Financing leases 44 20
Operating Leases $ 209 $ 93