Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities
Net income	$ 385,555	$ 258,966	$ 221,393
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	144,541	131,397	128,732
Provision for doubtful accounts	229	1,321	917
Amortization of debt issue costs	1,514	1,683	2,154
Stock-based compensation expense	6,127	6,391	6,164
Loss from disposition of fixed assets	3,886	1,375	581
Gain from sales of equity securities	(16,429)	0	0
Impairment of long-lived assets	0	1,975	0
Write-off of debt issuance costs	1,277	0	0
Deferred income taxes	(5,793)	14,114	14,153
Equity in loss (income) of joint ventures	3,005	(427)	(2,212)
Changes in operating assets and liabilities
Accounts receivable	6,450	(45,766)	(33,478)
Inventories	91,479	(40,749)	(80,611)
Prepaid expenses and other current assets	(2,205)	2,987	(7,217)
Accounts payable	(12,725)	20,311	25,644
Accrued liabilities	32,381	18,785	9,910
Other, net	(15,238)	(10,067)	(2,846)
Net cash provided by operating activities	624,054	362,296	283,284
Cash flows from investing activities
Additions to equity investments	0	0	(10,177)
Additions to property, plant and equipment	(386,882)	(176,843)	(81,269)
Construction of assets pending sale-leaseback	(4,308)	0	0
Proceeds from disposition of assets	471	2,880	914
Proceeds from repayment of loan to affiliate	1,192	1,192	763
Proceeds from sale-leaseback of assets	2,304	0	0
Proceeds from sales of equity securities	47,655	0	0
Purchase of securities and other investments	(127,834)	(30,265)	0
Settlements of derivative instruments	431	251	9,494
Net cash used for investing activities	(466,971)	(202,785)	(80,275)
Cash flows from financing activities
Capitalized debt issuance costs	(2,221)	(2,697)	(3,331)
Dividends paid	(285,521)	(18,265)	(16,014)
Proceeds from debt issuance	248,818	0	0
Proceeds from exercise of stock options	10,369	5,344	3,745
Repayment of debt	(250,000)	0	0
Repurchase of common stock for treasury	(10,784)	(2,518)	0
Utilization of restricted cash	96,433	54,227	197,298
Net cash (used for) provided by financing activities	(192,906)	36,091	181,698
Net (decrease) increase in cash and cash equivalents	(35,823)	195,602	384,707
Cash and cash equivalents at beginning of the year	825,901	630,299	245,592
Cash and cash equivalents at end of the year	$ 790,078	$ 825,901	$ 630,299