RESTRUCTURING CHARGES (Tables)

12 Months Ended

Dec. 31, 2018

Restructuring and Related Activities [Abstract]

Schedule of Restructuring Reserve by Type of Cost [Table Text Block]

The following table summarizes the 2018, 2017 and 2016 activities by major component of these restructuring actions and the remaining balances of accrued restructuring costs as of December 31, 2018:

	Employee severance and related benefit costs			Lease and other contract termination costs			Employee relocation costs			Facility exit costs			Write-off of equipment and facility			Total
	($ in millions)
Balance at January 1, 2016	$	4.6		$	2.1		$	—		$	—		$	—		$	6.7
2016 restructuring charges	5.1			13.6			2.1			15.5			76.6			112.9
Amounts utilized	(6.3		)	(8.2		)	(2.1		)	(13.7		)	(76.6		)	(106.9		)
Balance at December 31, 2016	3.4			7.5			—			1.8			—			12.7
2017 restructuring charges	2.0			22.1			0.3			11.7			1.5			37.6
Amounts utilized	(3.6		)	(26.3		)	(0.3		)	(13.5		)	(1.5		)	(45.2		)
Balance at December 31, 2017	1.8			3.3			—			—			—			5.1
2018 restructuring charges	1.7			5.6			—			12.0			2.6			21.9
Amounts utilized	(2.0		)	(2.9		)	—			(11.3		)	(2.6		)	(18.8		)
Balance at December 31, 2018	$	1.5		$	6.0		$	—		$	0.7		$	—		$	8.2

Restructuring and Related Costs [Table Text Block]

The following table summarizes the cumulative restructuring charges of these 2018, 2016, 2014 and 2010 restructuring actions by major component through December 31, 2018:

	Chlor Alkali Products and Vinyls				Winchester				Total
	Becancour		Capacity Reductions		Oxford		Geelong
	($ in millions)
Write-off of equipment and facility	$	3.5	$	78.1	$	—	$	2.6	$	84.2
Employee severance and related benefit costs	2.7		5.9		14.7		1.3		24.6
Facility exit costs	5.9		33.8		2.3		—		42.0
Pension and other postretirement benefits curtailment	—		—		4.1		—		4.1
Employee relocation costs	—		1.7		6.0		—		7.7
Lease and other contract termination costs	6.1		40.2		—		0.2		46.5
Total cumulative restructuring charges	$	18.2	$	159.7	$	27.1	$	4.1	$	209.1