XML 78 R57.htm IDEA: XBRL DOCUMENT v3.21.2
FAIR VALUE MEASUREMENTS (Schedule of Activity for Debt and Equity Securities) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Fair Value Disclosures [Abstract]        
Proceeds from sales and maturities of nuclear decommissioning trust investments $ 224 $ 890 $ 1,176 $ 1,144
Gross realized gains on securities 21 51 150 59
Gross realized losses on securities $ (2) $ (22) $ (18) $ (34)