XML 62 R51.htm IDEA: XBRL DOCUMENT v3.21.1
Derivatives and Risk Management Activities - Broker Receivable/Payable (Details) - USD ($)
$ in Millions
Mar. 31, 2021
Dec. 31, 2020
Offsetting Assets, Liabilities [Line Items]    
Initial margin $ 62 $ 91
Variation margin posted/(returned) 259 290
Letters of credit (130) (129)
Net broker receivable/(payable) 269 318
Exchange traded    
Offsetting Assets, Liabilities [Line Items]    
Letters of credit $ (52) $ (63)