Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating Activities
Net income (loss)	$ 27	$ (84)
Income from discontinued operations	0	4
Income (loss) from continuing operations	27	(88)
Adjustments to reconcile income (loss) from continuing operations to net cash:
Depreciation, depletion and amortization	77	78
Loss on extinguishment of debt	0	41
Long-lived asset impairment charges	0	1
Share-based compensation expense	9	13
Deferred income taxes	(1)	2
Noncash income tax benefit	0	(4)
Gain on asset dispositions	0	(7)
(Increase) decrease in working capital:
Receivables	(63)	(43)
Income taxes receivable	0	2
Inventories	(19)	(1)
Other current assets	(6)	3
Payables	(32)	(6)
Accrued expenses	(31)	(5)
Increase in other assets	1	1
Increase in other liabilities	(16)	(3)
Other, net	9	(1)
Net cash used for operating activities - continuing operations	(45)	(17)
Investing Activities
Purchases of marketable securities	(111)	(70)
Sales or maturities of marketable securities	104	227
Capital expenditures	(46)	(28)
Acquisition of mining rights	(17)	(16)
Net proceeds from asset dispositions	0	14
Investment in joint ventures	(5)	(11)
Loan to joint venture	0	(4)
Deposit of restricted cash	0	(16)
Net cash (used for) provided by investing activities - continuing operations	(75)	96
Financing Activities
Issuance of debt	3	248
Repayment of debt	(2)	(280)
Payment of debt issuance fees	0	(5)
Loans from joint venture partner	3	0
Issuance of common stock	2	1
Repurchases of common stock to satisfy employee tax withholding obligations	(9)	(5)
Net cash used for financing activities - continuing operations	(3)	(41)
Effect of exchange rate changes on cash	(7)	2
Net (decrease) increase in cash and cash equivalents	(130)	40
Cash and cash equivalents at beginning of period	546	365
Cash and cash equivalents at end of period	416	405
Supplemental Cash Flow Disclosures:
Interest paid, net of capitalized interest	96	105
Income taxes paid, net	3	0
Amount in accounts payable for capital expenditures	$ 5	$ 2