ACQUISITION (Details 2) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 05, 2015
Business Acquisition [Line Items]
Goodwill	$ 2,120.0	$ 2,118.0	$ 2,174.1
DCP Business
Business Acquisition [Line Items]
Total current assets				$ 883.7
Property, plant and equipment				3,079.1
Deferred tax assets				85.0
Intangible assets				612.6
Other assets				438.9
Total assets acquired				5,099.3
Total current liabilities				359.9
Long-term debt				517.9
Accrued pension liability				442.3
Deferred tax liabilities				1,017.7
Other liabilities				8.6
Total liabilities assumed				2,346.4
Net identifiable assets acquired				2,752.9
Goodwill				1,372.5
Fair value of net assets acquired				4,125.4
Initial Valuation [Member] | DCP Business
Business Acquisition [Line Items]
Total current assets				921.7
Property, plant and equipment				3,090.8
Deferred tax assets				76.8
Intangible assets				582.3
Other assets				426.5
Total assets acquired				5,098.1
Total current liabilities				357.6
Long-term debt				517.9
Accrued pension liability				447.1
Deferred tax liabilities				1,054.9
Other liabilities				2.0
Total liabilities assumed				2,379.5
Net identifiable assets acquired				2,718.6
Goodwill				1,427.5
Fair value of net assets acquired				4,146.1
Measurement Period Adjustments [Member] | DCP Business
Business Acquisition [Line Items]
Total current assets				(38.0)
Property, plant and equipment				(11.7)
Deferred tax assets				8.2
Intangible assets				30.3
Other assets				12.4
Total assets acquired				1.2
Total current liabilities				2.3
Long-term debt				0.0
Accrued pension liability				(4.8)
Deferred tax liabilities				(37.2)
Other liabilities				6.6
Total liabilities assumed				(33.1)
Net identifiable assets acquired				34.3
Goodwill				(55.0)
Fair value of net assets acquired				$ (20.7)