Condensed Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current Assets
Cash and cash equivalents	$ 1,389	$ 716
Accounts receivable, net of allowance for doubtful accounts of $1 million and $3 million, respectively	425	391
Inventories	749	914
Prepaid and other assets	37	38
Deferred income taxes	54	114
Total Current Assets	2,654	2,173
Noncurrent Assets
Property, plant and equipment, net	1,309	1,423
Mineral leaseholds, net	1,321	1,439
Intangible assets, net	313	326
Long-term deferred tax assets	170	91
Other long-term assets	80	59
Total Assets	5,847	5,511
Current Liabilities
Accounts payable	129	189
Accrued liabilities	180	209
Short-term Debt		30
Long-term debt due within one year	18	10
Income taxes payable	8	24
Current deferred income taxes	1	5
Total Current Liabilities	336	467
Noncurrent Liabilities
Long-term debt	2,390	1,605
Pension and postretirement healthcare benefits	177	176
Asset retirement obligations	96	106
Deferred income taxes	209	222
Other long-term liabilities	49	53
Total Liabilities	3,257	2,629
Contingencies and Commitments
Shareholders' Equity
Capital in excess of par value	1,441	1,429
Retained earnings	1,187	1,314
Accumulated other comprehensive loss	(245)	(95)
Total Shareholders' Equity	2,384	2,649
Noncontrolling interest	206	233
Total Equity	2,590	2,882
Total Liabilities and Equity	5,847	5,511
Class A common stock [Member]
Shareholders' Equity
Common stock, value	1	1
Total Equity	$ 1	$ 1