GOODWILL AND INTANGIBLES GOODWILL AND INTANGIBLES (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2016

Dec. 31, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill [Table Text Block]

Changes in the carrying value of goodwill were as follows:

	Chlor Alkali Products and Vinyls			Epoxy			Total
	($ in millions)
Balance at January 1, 2015	$	747.1		$	—		$	747.1
Acquisition activity	—			—			—
Balance at March 31, 2015	$	747.1		$	—		$	747.1
Balance at January 1, 2016	$	1,877.5		$	296.6		$	2,174.1
Acquisition activity	(23.3		)	(5.5		)	(28.8		)
Foreign currency translation adjustment	0.6			0.2			0.8
Balance at March 31, 2016	$	1,854.8		$	291.3		$	2,146.1

Changes in the carrying value of goodwill were as follows:

	Chlor Alkali Products and Vinyls			Epoxy			Total
	($ in millions)
Balance at January 1, 2014	$	747.1		$	—		$	747.1
Acquisition activity	—			—			—
Balance at December 31, 2014	747.1			—			747.1
Acquisition activity	1,130.8			296.7			1,427.5
Foreign currency translation adjustment	(0.4		)	(0.1		)	(0.5		)
Balance at December 31, 2015	$	1,877.5		$	296.6		$	2,174.1

Schedule of Finite-Lived Intangible Assets [Table Text Block]

Intangible assets consisted of the following:

	March 31, 2016								December 31, 2015								March 31, 2015
	Gross Amount		Accumulated Amortization				Net		Gross Amount		Accumulated Amortization				Net		Gross Amount		Accumulated Amortization				Net
	($ in millions)
Customers, customer contracts and relationships	$	643.8		$	(75.9	)	$	567.9	$	641.0		$	(64.0	)	$	577.0	$	152.9		$	(44.7	)	$	108.2
Trade name	17.9			(2.7		)	15.2		17.9			—			17.9		10.9			—			10.9
Acquired technology	85.2			(5.7		)	79.5		84.7			(2.7		)	82.0		—			—			—
Other	2.3			(1.7		)	0.6		2.3			(1.7		)	0.6		2.3			(1.6		)	0.7
Total intangible assets	$	749.2		$	(86.0	)	$	663.2	$	745.9		$	(68.4	)	$	677.5	$	166.1		$	(46.3	)	$	119.8

Intangible assets consisted of the following:

		December 31,
		2015							2014
	Useful Lives	Gross Amount		Accumulated Amortization			Net		Gross Amount		Accumulated Amortization			Net
		($ in millions)
Customers, customer contracts and relationships	(10-15 years)	$	641.0	$	(64.0	)	$	577.0	$	152.9	$	(41.0	)	$	111.9
Trade name	(indefinite)	17.9		—			17.9		10.9		—			10.9
Acquired technology	(7 years)	84.7		(2.7		)	82.0		—		—			—
Other	(4-10 years)	2.3		(1.7		)	0.6		2.3		(1.6		)	0.7
Total intangible assets		$	745.9	$	(68.4	)	$	677.5	$	166.1	$	(42.6	)	$	123.5