Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	$ (57.6)	$ (182.2)	$ (23.8)
Revenues
Sales	4,117.9	5,138.3	6,132.7
Other revenues	597.4	470.9	659.5
Total revenues	4,715.3	5,609.2	6,792.2
Costs and expenses
Operating costs and expenses (exclusive of items shown separately below)	4,107.6	5,007.7	5,716.9
Depreciation, depletion and amortization	465.4	572.2	655.7
Asset retirement obligation expenses	41.8	45.5	81.0
Selling and administrative expenses	153.4	176.4	227.1
Restructuring and pension settlement charges	15.5	23.5	26.0
Other operating (income) loss:
Net gain on disposal of assets	(23.2)	(45.0)	(41.4)
Asset impairment	247.9	1,277.8	154.4
(Gain) loss from equity affiliates	(16.2)	15.9	107.6
Operating loss	(276.9)	(1,464.8)	(135.1)
Interest Expense	298.6	465.4	426.6
Loss on early debt extinguishment	29.5	67.8	1.6
Interest income	(5.7)	(7.7)	(15.4)
Reorganization Items	159.0	0.0	0.0
Loss from continuing operations before income taxes	(758.3)	(1,990.3)	(547.9)
Income tax (benefit) provision	(94.5)	(207.1)	147.4
Loss from continuing operations, net of income taxes	(663.8)	(1,783.2)	(695.3)
Loss from discontinued operations, net of income taxes	(57.6)	(175.0)	(28.2)
Net loss	(721.4)	(1,958.2)	(723.5)
Less: Net income attributable to noncontrolling interests	7.9	7.1	9.7
Net loss attributable to common stockholders	$ (729.3)	$ (1,965.3)	$ (733.2)
Loss From Continuing Operations
Basic loss per share	$ (36.72)	$ (98.65)	$ (39.51)
Diluted loss per share	(36.72)	(98.65)	(39.51)
Net Loss Attributable to Common Stockholders
Basic loss per share	(39.87)	(108.29)	(41.08)
Diluted loss per share	(39.87)	(108.29)	(41.08)
Dividends declared per share	$ 0.000	$ 0.075	$ 5.100