XML 78 R61.htm IDEA: XBRL DOCUMENT v3.21.2
Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Fixed income securities - Nuclear decommissioning trust fund
$ in Millions
Jun. 30, 2021
USD ($)
Debt Securities, Available-for-sale [Line Items]  
Due within one year $ 7
Due after one through five years 151
Due after five through ten years 113
Due after ten years 288
Fixed income securities total $ 559