Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities
Net income	$ 360,468	$ 327,475
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	118,981	94,474
Recovery of doubtful accounts	228	311
Amortization of debt issuance costs	1,002	730
Stock-based compensation expense	4,905	4,511
Loss from disposition of fixed assets	890	1,872
Gain from sales of equity securities	(3,795)	0
Gain on acquisition, net of loss on the fair value remeasurement of preexisting equity interest	(21,045)	0
Impairment of equity method investment	4,925	0
Deferred income taxes	3,088	19,359
Windfall tax benefits from share-based payment arrangements	(1,895)	(4,436)
Income from equity method investments, net of dividends	(1,760)	(1,239)
Other gains (losses), net	423	(526)
Changes in operating assets and liabilities
Accounts receivable	(22,380)	(27,367)
Inventories	50,115	34,360
Prepaid expenses and other current assets	(10,844)	(5,480)
Accounts payable	(2,327)	(21,990)
Accrued liabilities	(40,526)	13,631
Other, net	(5,098)	(3,443)
Net cash provided by operating activities	435,355	432,242
Cash flows from investing activities
Acquisition of business, net of cash acquired	(15,782)	0
Additions to property, plant and equipment	(203,933)	(216,912)
Proceeds from disposition of assets	0	13
Proceeds from sales and maturities of securities	15,037	342,045
Purchase of securities	0	(117,332)
Settlements of derivative instruments	(1,174)	(290)
Net cash used for investing activities	(174,288)	7,524
Cash flows from financing activities
Dividends paid	(43,896)	(33,623)
Distributions to noncontrolling interests	(7,218)	0
Proceeds from exercise of stock options	831	4,187
Proceeds from issuance of notes payable	2,392	0
Repayment of notes payable	(4,299)	0
Repurchase of common stock for treasury	(62,804)
Windfall tax benefits from share-based payment arrangements	1,895	4,436
Net cash provided by financing activities	(113,099)	(25,000)
Effect of exchange rate changes on cash and cash equivalents	(2,000)	0
Net increase in cash and cash equivalents	145,968	414,766
Cash and cash equivalents at beginning of period	880,601	461,301
Cash and cash equivalents at end of period	$ 1,026,569	$ 876,067