Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows From Operating Activities
Net loss	$ (1,518.7)	$ (264.3)
Loss (income) from discontinued operations, net of income taxes	202.7	(6.0)
Loss from continuing operations, net of income taxes	(1,316.0)	(270.3)
Adjustments to reconcile loss from continuing operations, net of income taxes to net cash (used in) provided by operating activities:
Depreciation, depletion and amortization	430.6	483.9
Noncash interest expense	22.9	17.7
Deferred income taxes	(53.7)	(44.3)
Noncash share-based compensation	20.0	35.8
Asset impairment	900.8	0.0
Net gain on disposal of assets	(20.2)	(25.9)
Loss from equity affiliates	12.3	44.0
Gains on previously monetized foreign currency hedge positions	(14.9)	(106.7)
Changes in current assets and liabilities:
Accounts receivable	190.0	142.0
Change in receivable from accounts receivable securitization program	(5.0)	(75.0)
Inventories	55.2	20.5
Net assets from coal trading activities	(17.4)	(14.6)
Other current assets	7.6	4.4
Accounts payable and accrued expenses	(322.0)	76.2
Asset retirement obligations	28.1	28.4
Accrued postretirement benefit costs	14.2	12.7
Accrued pension costs	21.1	14.6
Other, net	(15.6)	2.4
Net cash (used in) provided by continuing operations	(62.0)	345.8
Net cash used in discontinued operations	(28.6)	(95.7)
Net cash (used in) provided by operating activities	(90.6)	250.1
Cash Flows From Investing Activities
Additions to property, plant, equipment and mine development	(76.9)	(107.5)
Changes in accrued expenses related to capital expenditures	(14.5)	(22.8)
Federal coal lease expenditures	(89.8)	(89.4)
Proceeds from disposal of assets, net of notes receivable	39.6	152.5
Purchases of debt and equity securities	(22.6)	(6.0)
Proceeds from sales and maturities of debt and equity securities	33.6	7.7
Contributions to joint ventures	(349.8)	(410.4)
Distributions from joint ventures	339.8	408.5
Advances to related parties	(3.6)	(19.7)
Other, net	(2.1)	(2.5)
Net cash used in investing activities	(146.3)	(89.6)
Cash Flows From Financing Activities
Proceeds from long-term debt	975.7	1.1
Repayments of long-term debt	(666.0)	(15.6)
Payment of deferred financing costs	(28.7)	(10.1)
Dividends paid	(1.4)	(69.2)
Restricted cash for distributions to noncontrolling interests	0.0	(42.5)
Other, net	(6.4)	(1.7)
Net cash provided by (used in) financing activities	273.2	(138.0)
Net change in cash and cash equivalents	36.3	22.5
Cash and cash equivalents at beginning of period	298.0	444.0
Cash and cash equivalents at end of period	$ 334.3	$ 466.5