XML 112 R93.htm IDEA: XBRL DOCUMENT v3.20.4
Debt - Line of Credit and Commercial Paper - Schedule of Unsecured Revolving Credit Facility (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Nov. 04, 2019
Nov. 03, 2019
Nov. 01, 2019
Oct. 31, 2019
Line of Credit Facility [Line Items]            
Commercial paper balance outstanding $ (415,000,000.0) $ (1,000,000,000.0) $ (1,000,000,000.0) $ (500,000,000.0)    
Unsecured Revolving Credit Facility [Member]            
Line of Credit Facility [Line Items]            
Unsecured revolving credit facility commitment 2,500,000,000 2,500,000,000     $ 2,500,000,000 $ 2,000,000,000.0
Commercial paper balance outstanding (415,000,000) (1,000,000,000)        
Unsecured revolving credit facility balance outstanding   (20,000,000)        
Other restricted amounts (100,949,000) (100,929,000)        
Unsecured revolving credit facility availability $ 1,984,051,000 $ 1,379,071,000