Note 5. Income Taxes (Detail) - Reconciliation of Statutory Federal Income Tax Rate to Annual Tax Provision (Benefit) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Computed “statutory” (benefit) provision	$ 81,600	$ (26,092)	$ 21,051
Computed “statutory” (benefit) provision	35.00%	(35.00%)	35.00%
Percentage depletion	(13,751)	(8,858)	(7,953)
Percentage depletion	(6.00%)	(12.00%)	(16.00%)
Net increase (utilization) of U.S. and foreign tax loss carryforwards	3,822	2,713	(13,098)
Net increase (utilization) of U.S. and foreign tax loss carryforwards	2.00%	3.00%	(19.00%)
Change in valuation allowance other than utilization		(88,069)	(7,100)
Change in valuation allowance other than utilization		(118.00%)	(12.00%)
Tax loss carryback from change in tax law			(1,989)
Tax loss carryback from change in tax law			(3.00%)
State taxes, net of federal taxes	10,890	(4,717)	33
State taxes, net of federal taxes	5.00%	(6.00%)
Effect of U.S. AMT, foreign taxes other	(583)	1,491	1,376
Effect of U.S. AMT, foreign taxes other	(1.00%)	2.00%	2.00%
	$ 81,978	$ (123,532)	$ (7,680)
	35.00%	(166.00%)	(13.00%)