XML 110 R77.htm IDEA: XBRL DOCUMENT v3.10.0.1
Notes Receivable (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Sale of notes receivable $ 0 $ 50 $ 0
Consumer retail installment contracts 1,857 1,371  
EnerBank      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Sale of notes receivable   52  
Unearned income 102 84  
Delinquent loans 21 14  
Loans modified as troubled debt restructurings 1 $ 1  
Retail Installment Contracts | EnerBank      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Consumer retail installment contracts $ 205