Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows From Operating Activities
Net loss	$ (398.9)	$ (1,216.8)
Loss from discontinued operations, net of income taxes	6.4	45.2
Loss from continuing operations, net of income taxes	(392.5)	(1,171.6)
Adjustments to reconcile loss from continuing operations, net of income taxes to net cash used in operating activities:
Depreciation, depletion and amortization	227.7	294.6
Noncash interest expense	16.3	15.2
Deferred income taxes	(66.9)	(89.6)
Noncash share-based compensation	5.1	13.6
Asset impairment	17.2	900.8
Net gain on disposal of assets	(15.5)	(12.3)
Loss from equity affiliates	9.7	7.0
Gain on VEBA settlement	(68.1)	0.0
Settlement of hedge positions	(25.0)	0.0
Gains on previously monetized foreign currency hedge positions	0.0	(14.8)
Noncash reorganization items, net	96.8	0.0
Restricted cash	(79.7)	0.0
Changes in current assets and liabilities:
Accounts receivable	34.4	178.1
Change in receivable from accounts receivable securitization program	(168.5)	80.0
Inventories	3.7	7.5
Net assets from coal trading activities	6.3	(12.9)
Other current assets	(33.4)	(3.6)
Accounts payable and accrued expenses	(16.7)	(277.9)
Asset retirement obligations	14.2	20.5
Accrued postretirement benefit costs	(0.6)	11.1
Accrued pension costs	11.5	14.9
Take-or-pay obligation settlement	(15.5)	0.0
Other, net	11.9	(13.0)
Net cash used in continuing operations	(427.6)	(52.4)
Net cash used in discontinued operations	(4.2)	(4.0)
Net cash used in operating activities	(431.8)	(56.4)
Cash Flows From Investing Activities
Additions to property, plant, equipment and mine development	(38.1)	(50.9)
Changes in accrued expenses related to capital expenditures	(7.1)	(13.2)
Proceeds from disposal of assets, net of notes receivable	116.0	23.9
Purchases of debt and equity securities	0.0	(17.9)
Proceeds from sales and maturities of debt and equity securities	0.0	27.1
Contributions to joint ventures	(159.7)	(239.8)
Distributions from joint ventures	163.5	236.7
Other, net	(8.9)	(2.0)
Net cash provided by (used in) investing activities	65.7	(36.1)
Cash Flows From Financing Activities
Proceeds from long-term debt	1,422.0	975.7
Repayments of long-term debt	(9.0)	(660.7)
Payment of deferred financing costs	(29.5)	(28.7)
Dividends paid	0.0	(1.4)
Distributions to noncontrolling interests	(2.5)	(1.8)
Other, net	(1.9)	(1.5)
Net cash provided by financing activities	1,379.1	281.6
Net change in cash and cash equivalents	1,013.0	189.1
Cash and cash equivalents at beginning of period	261.3	298.0
Cash and cash equivalents at end of period	$ 1,274.3	$ 487.1