Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows from Operating Activities:
Net Income	$ (82,209)	$ (5,402)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	113,971	106,967
Deferred income tax provision	(23,034)	(23,771)
Net loss (gain) on sales of property and equipment	860	320
Noncash compensation	5,985	7,710
Excluding the effects of acquisitions, increase (decrease) in cash from:
Accounts receivable	(12,161)	23,293
Inventory	(3,901)	13,494
Other operating assets	473	(10,855)
Currency translation effect on working capital	(2,771)	(5,961)
Current liabilities	3,941	(25,258)
Other operating liabilities	14,531	22,067
Total adjustments to net income	97,894	108,006
Net Cash Provided by Operating Activities	15,685	102,604
Cash Flows from Investing Activities:
Purchases of property and equipment	(53,530)	(41,300)
Payments to Acquire Businesses, Net of Cash Acquired	(68,398)	0
Proceeds from Sale of Available-for-sale Securities, Debt	33,405	0
Payments for (Proceeds from) Other Investing Activities	(10,025)	(1,014)
Distributions of capital from unconsolidated affiliates	2,372	1,424
Dispositions of property and equipment	1,403	630
Net Cash Used in Investing Activities	(94,773)	(40,260)
Cash Flows from Financing Activities:
Proceeds from Issuance of Long-term Debt	295,816	0
Repayments of Long-term Debt	(300,000)	0
Cash Dividends	0	(29,479)
Proceeds from (Payments for) Other Financing Activities	(1,594)	(2,049)
Net Cash Provided by (Used in) Financing Activities	(5,778)	(31,528)
Effect of Exchange Rate on Cash and Cash Equivalents	(5,909)	1,330
Net Increase (Decrease) in Cash and Cash Equivalents	(90,775)	32,146
Cash and Cash Equivalents-Beginning of Period	430,316	450,193
Cash and Cash Equivalents-End of Period	$ 339,541	$ 482,339