Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities
Net income	$ 244,556	$ 360,468
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	132,964	118,981
Provision for doubtful accounts	403	228
Amortization of debt issuance costs	417	1,002
Stock-based compensation expense	5,084	4,905
Loss from disposition of property, plant and equipment	3,331	890
Gains from sales of securities	(1,319)	(3,795)
Gain on acquisition, net of loss on the fair value remeasurement of preexisting equity interest	0	(21,045)
Impairment of equity method investment	0	4,925
Deferred income taxes	102,990	3,088
Windfall tax benefits from share-based payment arrangements	(319)	(1,895)
Loss (income) from equity method investments, net of dividends	279	(1,760)
Other losses, net	1,210	423
Changes in operating assets and liabilities
Accounts receivable	(72,996)	(22,380)
Inventories	(12,719)	50,115
Prepaid expenses and other current assets	(12,586)	(10,844)
Accounts payable	54,394	(2,327)
Accrued liabilities	(1,617)	(40,526)
Other, net	(74,180)	(5,098)
Net cash provided by operating activities	369,892	435,355
Cash flows from investing activities
Acquisition of business, net of cash acquired	0	15,782
Additions to property, plant and equipment	(287,160)	(203,933)
Proceeds from disposition of assets	105	0
Proceeds from sales and maturities of securities	302,432	15,037
Purchase of securities	(138,422)
Settlements of derivative instruments	(3,372)	(1,174)
Net cash used for investing activities	(126,417)	(174,288)
Cash flows from financing activities
Debt issuance costs	(9,700)	0
Dividends paid	(47,317)	(43,896)
Distributions to noncontrolling interests	(8,084)	(7,218)
Proceeds from exercise of stock options	481	831
Proceeds from issuance of notes payable	3,842	2,392
Repayment of notes payable	(8,626)	(4,299)
Repurchase of common stock for treasury	(67,404)	(62,804)
Windfall tax benefits from share-based payment arrangements	319	1,895
Net cash provided by financing activities	(136,489)	(113,099)
Effect of exchange rate changes on cash and cash equivalents	1,486	(2,000)
Net increase in cash and cash equivalents	108,472	145,968
Cash and cash equivalents at beginning of period	662,525	880,601
Cash and cash equivalents at end of period	$ 770,997	$ 1,026,569