Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Allowance for Doubtful Accounts) (Details)

v3.19.3.a.u2
Summary of Significant Accounting Policies (Allowance for Doubtful Accounts) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]      
Schedule of Accounts Receivable The following table illustrates the Company’s allowance for doubtful accounts activity for the years ended December 31:
 
2019
 
2018
 
2017
Beginning Balance
$
52

 
$
61

 
$
77

Bad debt expense
16

 
8

 
7

Write-offs
(21
)
 
(17
)
 
(23
)
Ending Balance
$
47

 
$
52

 
$
61


   
Accounts Receivable, Allowance for Credit Loss [Roll Forward]      
Beginning Balance $ 52 $ 61 $ 77
Bad debt expense 16 8 7
Write-offs (21) (17) (23)
Ending Balance $ 47 $ 52 $ 61