XML 81 R63.htm IDEA: XBRL DOCUMENT v3.20.4
Financial Instruments (Credit Facilities) (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Line of Credit Facility [Line Items]    
Line of credit facility, maximum borrowing capacity $ 79,000,000  
Revolving credit facility, minimum interest coverage ratio 3.50  
Borrowings outstanding $ 4,000,000  
Short-term Debt 4,000,000 $ 0
Revolving Credit Facility    
Line of Credit Facility [Line Items]    
Revolving credit facility, current borrowing capacity 1,000,000,000.0  
Line of credit facility, maximum borrowing capacity $ 1,500,000,000  
Maximum total leverage ratio 3.50  
Revolving credit facility, covenant compliance ratio 4.00  
Borrowings outstanding $ 0  
Operational Efficiency    
Line of Credit Facility [Line Items]    
Charges add back $ 100,000,000