CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net cash flows provided by operating activities	$ 110,488	$ 88,381
Cash flows from investing activities
Acquisitions, net of cash received	(33,029)
Purchases of property, plant and equipment	(50,698)	(52,990)
Purchases of short-term investments	(9,000)	(10,171)
Proceeds from maturity of short-term investments	9,843	7,289
Other	367	2,245
Net cash and cash equivalents used in investing activities	(82,517)	(53,627)
Cash flows from financing activities
Advances on lines of credit and short-term debt	6,769	3,414
Repayments of line of credit and short-term debt	(1,461)
Taxes paid related to net share settlement	(1,595)	(8,617)
Proceeds from long-term debt	161,237	189,656
Repayments of long-term debt	(203,385)	(272,170)
Net proceeds from issuance of common stock	6,706	3,009
Repayment of and proceeds from finance lease obligation	(588)	1,775
Dividend distribution to noncontrolling interests	(1,180)	(1,151)
Other	542	654
Net cash and cash equivalents used in financing activities	(32,955)	(83,430)
Effect of exchange rate changes on cash and cash equivalents	(35)	(2,753)
Change in cash and cash equivalents, including restricted cash	(5,019)	(51,429)
Cash and cash equivalents, beginning of period, including restricted cash	241,833	205,202
Cash and cash equivalents, end of period, including restricted cash	236,814	153,773
Supplemental Cash Flow Information
Interest paid during the period	4,107	5,334
Taxes paid during the period	23,199	16,643
Non-cash investing and financing activities:
(Increase) decrease in accounts payable related to the purchase of property, plant and equipment	(2,038)	5,452
Noncontrolling Interest
Non-cash investing and financing activities:
Increase in dividend accrued for noncontrolling interest	$ (1,400)	$ (1,427)