Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities
Net income	$ 610,425	$ 385,555	$ 258,966
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	157,808	144,541	131,397
Provision for doubtful accounts	5,514	229	1,321
Amortization of debt issue costs	1,459	1,514	1,683
Stock-based compensation expense	6,966	6,127	6,391
Loss from disposition of fixed assets	5,039	3,886	1,375
Gain from sales of equity securities	0	(16,429)	0
Impairment of long-lived assets	0	0	1,975
Write-off of debt issuance costs	0	1,277	0
Deferred income taxes	93,732	(5,793)	14,114
Windfall tax benefits from share-based payment arrangements	(5,449)	(11,967)	(3,361)
Loss (income) from equity method investments, net of dividends	199	3,005	(427)
Other loss, net	391	0	0
Changes in operating assets and liabilities
Accounts receivable	(14,830)	6,450	(45,766)
Inventories	(46,633)	91,479	(40,749)
Prepaid expenses and other current assets	(475)	(2,205)	2,987
Accounts payable	13,820	(12,725)	20,311
Accrued liabilities	(15,147)	32,381	18,785
Other, net	(60,090)	(15,238)	(10,067)
Net cash provided by operating activities	752,729	612,087	358,935
Cash flows from investing activities
Acquisition of business	(178,309)	0	0
Additions to equity investments	(23,338)	0	0
Additions to property, plant and equipment	(679,222)	(386,882)	(176,843)
Construction of assets pending sale-leaseback	(136)	(4,308)	0
Proceeds from disposition of assets	151	471	2,880
Proceeds from repayment of loan to affiliate	167	1,192	1,192
Proceeds from sale-leaseback of assets	0	2,304	0
Proceeds from sales and maturities of equity securities	252,519	47,655	0
Purchase of securities and other investments	(367,150)	(127,834)	(30,265)
Payments for (Proceeds from) Derivative Instrument, Investing Activities	6,920	(431)	(251)
Net cash used for investing activities	(1,002,238)	(466,971)	(202,785)
Cash flows from financing activities
Capitalized debt issuance costs	0	(2,221)	(2,697)
Dividends paid	(55,236)	(285,521)	(18,265)
Proceeds from debt issuance	0	248,818	0
Proceeds from exercise of stock options	3,437	10,369	5,344
Repayment of debt	0	(250,000)	0
Repurchase of common stock for treasury	(32,918)	(10,784)	(2,518)
Utilization of restricted cash	0	96,433	54,227
Windfall tax benefits from share-based payment arrangements	5,449	11,967	3,361
Net cash (used for) provided by financing activities	(79,268)	(180,939)	39,452
Net (decrease) increase in cash and cash equivalents	(328,777)	(35,823)	195,602
Cash and cash equivalents at beginning of the year	790,078	825,901	630,299
Cash and cash equivalents at end of the year	$ 461,301	$ 790,078	$ 825,901