XML 64 R31.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2019
Summary of Significant Accounting Policies [Abstract]  
Allowance for Doubtful Accounts Activity The following table presents our allowance for doubtful accounts activity for the years indicated:

 
  
For the Year Ended December 31,
  
 
  
2019
    
2018
    
2017
  
Balance at beginning of period
  
$
11.5
    
$
12.1
    
$
11.3
  
Charged to costs and expenses
    
1.2
      
0.7
      
2.7
  
Deductions
    
(0.3
)
    
(1.3
)
    
(1.9
)
Balance at end of period
  
$
12.4
    
$
11.5
    
$
12.1
  
Cash, Cash Equivalents and Restricted Cash
 
  
December 31,
  
 
  
2019
    
2018
  
Cash and cash equivalents
  
$
334.7
    
$
344.8
  
Restricted cash
    
75.3
      
65.3
  
Total cash, cash equivalents and restricted cash shown in the
   Statements of Consolidated Cash Flows
  
$
410.0
    
$
410.1
  
Environmental Reserves Activity The following table presents the activity of our environmental reserves for the years indicated:

 
  
For the Year Ended December 31,
  
 
  
2019
    
2018
    
2017
  
Balance at beginning of period
  
$
6.9
    
$
11.6
    
$
11.9
  
Charged to costs and expenses
    
12.3
      
8.2
      
12.1
  
Acquisition-related additions and other
    
2.5
      
1.7
      
1.7
  
Deductions
    
(14.5
)
    
(14.6
)
    
(14.1
)
Balance at end of period
  
$
7.2
    
$
6.9
    
$
11.6