Accounts Receivable
 12 Months Ended
Dec. 31, 2016
Receivables [Abstract]  
Accounts Receivable

Note 6. Accounts Receivable

Transactions affecting the allowances for doubtful accounts receivable during the years ended December 31, 2016, 2015 and 2014 were as follows:

 

 

2016

 

 

2015

 

 

2014

 

Balance, beginning of year

$

4.6

 

 

$

3.9

 

 

$

4.9

 

Provisions charged to expense

 

3.1

 

 

 

0.5

 

 

 

1.4

 

Write-offs and other

 

(1.3

)

 

 

0.2

 

 

 

(2.4

)

Balance, end of year

$

6.4

 

 

$

4.6

 

 

$

3.9