CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current Assets
Cash and cash equivalents	$ 1,279	$ 1,478
Accounts receivable, net of allowance for doubtful accounts	277	308
Inventories, net	770	759
Prepaid and other assets	42	61
Deferred tax assets	13	47
Total current assets	2,381	2,653
Noncurrent Assets
Property, plant and equipment, net	1,227	1,258
Mineral leaseholds, net	1,058	1,216
Intangible assets, net	272	300
Inventories, net	57	0
Long-term deferred tax assets	9	192
Other long-term assets	61	80
Total assets	5,065	5,699
Current Liabilities
Accounts payable	160	164
Accrued liabilities	147	146
Long-term debt due within one year	18	18
Income taxes payable	32	28
Deferred tax liabilities	9	7
Total current liabilities	366	363
Noncurrent Liabilities
Long-term debt	2,375	2,395
Pension and postretirement healthcare benefits	172	148
Asset retirement obligations	85	90
Long-term deferred tax liabilities	204	204
Other long-term liabilities	75	62
Total liabilities	3,277	3,262
Contingencies and Commitments
Shareholders' Equity
Capital in excess of par value	1,476	1,448
Retained earnings	529	1,073
Accumulated other comprehensive loss	(396)	(284)
Total shareholders' equity	1,610	2,238
Noncontrolling interest	178	199
Total equity	1,788	2,437
Total liabilities and equity	5,065	5,699
Class A [Member]
Shareholders' Equity
Common stock, value	1	1
Class B [Member]
Shareholders' Equity
Common stock, value	$ 0	$ 0