SHAREHOLDERS' EQUITY (Tables)
 12 Months Ended
Dec. 31, 2019
Stockholders' Equity Note [Abstract]  
Activity included in accumulated other comprehensive loss table
The following table represents the activity included in accumulated other comprehensive loss:
 
Foreign Currency Translation Adjustment (net of taxes)
 
Unrealized (Losses) Gains on Derivative Contracts (net of taxes)
 
Pension and Other Postretirement Benefits (net of taxes)
 
Accumulated Other Comprehensive Loss
 
($ in millions)
Balance at January 1, 2017
$
(24.1
)
 
$
12.8

 
$
(498.7
)
 
$
(510.0
)
Unrealized gains (losses)
55.6

 
1.9

 
(27.3
)
 
30.2

Reclassification adjustments of (gains) losses into income
—

 
(4.6
)
 
26.9

 
22.3

Tax (provision) benefit
(23.9
)
 
1.0

 
(4.2
)
 
(27.1
)
Net change
31.7

 
(1.7
)
 
(4.6
)
 
25.4

Balance at December 31, 2017
7.6

 
11.1

 
(503.3
)
 
(484.6
)
Unrealized losses
(22.2
)
 
(1.1
)
 
(98.5
)
 
(121.8
)
Reclassification adjustments of (gains) losses into income
—

 
(14.3
)
 
37.0

 
22.7

Tax benefit (provision)
—

 
3.7

 
14.9

 
18.6

Net change
(22.2
)
 
(11.7
)
 
(46.6
)
 
(80.5
)
Income tax reclassification adjustment
15.3

 
2.4

 
(103.6
)
 
(85.9
)
Balance at December 31, 2018
0.7

 
1.8

 
(653.5
)
 
(651.0
)
Unrealized losses
(9.1
)
 
(23.0
)
 
(183.9
)
 
(216.0
)
Reclassification adjustments of (gains) losses into income
—

 
2.8

 
29.1

 
31.9

Tax benefit (provision)
—

 
4.8

 
26.9

 
31.7

Net change
(9.1
)
 
(15.4
)
 
(127.9
)
 
(152.4
)
Balance at December 31, 2019
$
(8.4
)
 
$
(13.6
)
 
$
(781.4
)
 
$
(803.4
)