XML 134 R111.htm IDEA: XBRL DOCUMENT v3.20.4
Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Nuclear decommissioning trusts - Fixed Income Securities
$ in Millions
Dec. 31, 2020
USD ($)
Debt Securities, Available-for-sale [Line Items]  
Due within one year $ 51
Due after one through five years 101
Due after five through ten years 89
Due after ten years 232
Fixed income securities total $ 473