ALLOWANCE FOR DOUBTFUL ACCOUNTS RECEIVABLES (Tables)
 9 Months Ended
Sep. 30, 2016
Accounts Receivable, Net [Abstract]  
Allowance for Doubtful Accounts Receivable
Allowance for doubtful accounts receivable consisted of the following:
 
September 30,
 
2016
 
2015
 
($ in millions)
Balance at beginning of year
$
6.4

 
$
3.0

Provisions charged (credited)
3.6

 
(0.4
)
Write-offs, net of recoveries
(0.8
)
 
(0.1
)
Balance at end of period
$
9.2

 
$
2.5