ACQUISITION (Details 2) - USD ($)
$ in Millions
Sep. 30, 2016
Dec. 31, 2015
Oct. 05, 2015
Sep. 30, 2015
Dec. 31, 2014
Business Acquisition [Line Items]          
Goodwill $ 2,119.4 $ 2,174.1   $ 747.1 $ 747.1
DCP Business          
Business Acquisition [Line Items]          
Total current assets     $ 883.7    
Property, plant and equipment     3,079.1    
Deferred taxes     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 liability     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 | DCP Business          
Business Acquisition [Line Items]          
Total current assets     921.7    
Property, plant and equipment     3,090.8    
Deferred taxes     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 liability     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 | DCP Business          
Business Acquisition [Line Items]          
Total current assets     (38.0)    
Property, plant and equipment     (11.7)    
Deferred taxes     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 liability     (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)