Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities
Net income	$ 290,278	$ 232,523
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	109,601	98,244
(Recovery of) provision for doubtful accounts	(536)	917
Amortization of debt issuance costs	1,149	1,289
Stock-based compensation expense	4,640	4,762
Loss from disposition of fixed assets	1,945	1,022
Gain from sales of equity securities	(16,429)	0
Impairment of long-lived assets	0	1,975
Write-off of debt issuance costs	1,277	0
Deferred income taxes	4,385	19,435
Equity in loss (income) of joint ventures	2,567	(2,443)
Changes in operating assets and liabilities
Accounts receivable	13,732	(100,524)
Inventories	119,240	(16,220)
Prepaid expenses and other current assets	(1,977)	4,039
Accounts payable	(35,651)	(9,558)
Accrued liabilities	20,077	14,330
Other, net	(13,675)	(5,438)
Net cash (used for) provided by operating activities	500,623	244,353
Cash flows from investing activities
Additions to property, plant and equipment	(235,463)	(111,823)
Construction of assets pending sale-leaseback	(5,484)	0
Proceeds from disposition of assets	435	2,456
Proceeds from repayment of loan to affiliate	763	763
Proceeds from sales of equity securities	47,655	0
Purchase of investments	(2,961)	(29,877)
Settlements of derivative instruments	471	(331)
Net cash provided by (used for) investing activities	(194,584)	(138,812)
Cash flows from financing activities
Capitalized debt issuance costs	(2,221)	(2,540)
Dividends paid	(22,345)	(13,359)
Proceeds from borrowings	248,818	0
Proceeds from exercise of stock options	6,627	5,323
Repayment of borrowings	(250,000)	0
Repurchase of common stock for treasury	(10,784)	(19)
Utilization of restricted cash	96,433	33,694
Net cash provided by (used for) financing activities	66,528	23,099
Net increase (decrease) in cash and cash equivalents	372,567	128,640
Cash and cash equivalents at beginning of period	825,901	630,299
Cash and cash equivalents at end of period	$ 1,198,468	$ 758,939