XML 72 R52.htm IDEA: XBRL DOCUMENT v3.20.2
Revenue Recognition Provision for Doubtful Accounts (Details) - Accounting Standards Update 2016-13 [Member]
$ in Millions
 9 Months Ended
Sep. 30, 2020
USD ($)
Cumulative Effect on Retained Earnings $ 5
Energy Services Disposal Group [Member]  
Cumulative Effect on Retained Earnings 2
CERC Corp [Member]  
Cumulative Effect on Retained Earnings $ 5