Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash Flows From Operating Activities
Net loss	$ (44.1)	$ (19.4)
(Income) loss from discontinued operations, net of income taxes	(0.2)	9.1
Loss from continuing operations, net of income taxes	(44.3)	(10.3)
Adjustments to reconcile loss from continuing operations, net of income taxes to net cash provided by operating activities:
Depreciation, depletion and amortization	157.2	170.7
Noncash interest expense	5.9	5.6
Deferred income taxes	(69.9)	(47.8)
Share-based compensation	13.5	11.8
Net gain on disposal or exchange of assets	(9.8)	(2.6)
Loss from equity affiliates	6.6	17.6
Gains on previously monetized foreign currency hedge positions	(40.9)	0
Changes in current assets and liabilities:
Accounts receivable	47.5	77.5
Change in receivable from accounts receivable securitization program	55.0	0
Inventories	(42.7)	(23.3)
Net assets from coal trading activities	(5.7)	25.3
Other current assets	(5.5)	7.1
Accounts payable and accrued expenses	47.1	43.5
Asset retirement obligations	9.5	12.7
Accrued postretirement benefit costs	3.6	3.8
Accrued pension costs	5.4	12.5
Other, net	(5.6)	(16.6)
Net cash provided by continuing operations	126.9	287.5
Net cash used in discontinued operations	(72.8)	(15.8)
Net cash provided by operating activities	54.1	271.7
Cash Flows From Investing Activities
Additions to property, plant, equipment and mine development	(24.4)	(74.0)
Changes in accrued expenses related to capital expenditures	(18.3)	(66.4)
Proceeds from disposal of assets, net of notes receivable	99.8	53.0
Purchases of debt securities	(2.0)	(4.6)
Proceeds from sales and maturities of debt securities	0.4	12.9
Contributions to joint ventures	(151.8)	(154.1)
Distributions from joint ventures	138.2	174.3
Advances to related parties	(3.1)	(23.1)
Repayments of loans from related parties	1.5	14.8
Other, net	(0.6)	(1.0)
Net cash provided by (used in) continuing operations	39.7	(68.2)
Net cash used in discontinued operations	0	(0.1)
Net cash provided by (used in) investing activities	39.7	(68.3)
Cash Flows From Financing Activities
Repayments of long-term debt	(5.2)	(108.5)
Dividends paid	(23.1)	(22.9)
Repurchase of employee common stock relinquished for tax withholding	(2.0)	(2.6)
Other, net	0.6	1.3
Net cash used in financing activities	(29.7)	(132.7)
Net change in cash and cash equivalents	64.1	70.7
Cash and cash equivalents at beginning of period	444.0	558.8
Cash and cash equivalents at end of period	$ 508.1	$ 629.5