DISCONTINUED OPERATIONS Schedule of Disposal Groups, including Discontinued Operations, Income Statement - North American Coal (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Disposal Groups, Including Discontinued Operations, Assets and Liabilities [Line Items]
Discontinued Operation, Tax Effect of Discontinued Operation	$ (6.0)	$ (1,216.0)	$ (184.5)
LOSS FROM DISCONTINUED OPERATIONS, net of tax	(892.1)	(8,368.0)	(517.1)
North American Coal [Member]
Schedule of Disposal Groups, Including Discontinued Operations, Assets and Liabilities [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	392.9	687.1	821.9
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	(449.2)	(822.9)	(836.4)
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)	(56.3)	(135.8)	(14.5)
Disposal Group, Including Discontinued Operation, Operating Expense	(30.4)	(20.8)	(13.8)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	9.3	(419.6)	0.0
Disposal Group, Including Discontinued Operation, Other Expense	(1.8)	(3.0)	(2.4)
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	(79.2)	(579.2)	(3.1)
Impairment of Long-Lived Assets to be Disposed of	(73.4)	(857.5)	0.0
Discontinued Operation, Tax Effect of Discontinued Operation	0.2	302.2	(6.2)
LOSS FROM DISCONTINUED OPERATIONS, net of tax	$ (152.4)	$ (1,134.5)	$ (9.3)