Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 1,198,468	$ 825,901
Accounts receivable, net	393,592	407,372
Inventories	371,537	490,777
Prepaid expenses and other current assets	14,472	12,495
Deferred income taxes	19,736	19,611
Total current assets	1,997,805	1,756,156
Property, plant and equipment, net	1,394,198	1,232,066
Equity investments	44,174	46,741
Restricted cash		96,283
Other assets, net	107,997	135,575
Total assets	3,544,174	3,266,821
Current liabilities
Accounts payable	199,438	227,034
Accrued liabilities	163,369	137,561
Total current liabilities	362,807	364,595
Long-term debt	763,731	764,563
Deferred income taxes	335,394	330,791
Other liabilities	48,814	50,560
Total liabilities	1,510,746	1,510,509
Commitments and contingencies (Notes 6 and 13)
Stockholders' equity
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.01 par value, 150,000,000 shares authorized; 66,981,077 and 66,601,909 shares issued at September 30, 2012 and December 31, 2011, respectively	670	666
Common stock, held in treasury, at cost; 284,493 and 69,816 shares at September 30, 2012 and December 31, 2011, respectively	(13,302)	(2,518)
Additional paid-in capital	486,852	467,796
Retained earnings	1,567,371	1,299,438
Accumulated other comprehensive loss	(8,163)	(9,070)
Total stockholders' equity	2,033,428	1,756,312
Total liabilities and stockholders' equity	$ 3,544,174	$ 3,266,821