XML 72 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9
Valuation and Qualifying Accounts (Tables)
 12 Months Ended
Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]  
Schedule of Valuation and Qualifying Accounts
The table below provides changes in the allowance for doubtful accounts over each period.
(in millions)
2014
 
2013
 
2012
Balance at beginning of year
$
22

 
$
25

 
$
29

Additions charged to expense
9

 
8

 
4

Deductions/other
(7
)
 
(11
)
 
(8
)
Balance at end of year
$
24

 
$
22

 
$
25