CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities
Cash flows from operating activities	$ 65,437	$ 41,860
Cash flows from investing activities
Decrease in restricted cash	650	36
Purchases of property, plant and equipment	(43,883)	(29,072)
Purchases of short-term investments	(9,821)	(13,238)
Proceeds from maturity of short-term investments	24,108	32,771
Other	(553)	(664)
Net cash and cash equivalents used in investing activities	(29,499)	(10,167)
Cash flows from financing activities
Advances on lines of credit and short-term debt	392
Taxes paid related to net share settlement	(128)	(2,494)
Debt issuance costs	(83)	(307)
Proceeds from long-term debt	7,500	1,500
Repayments of long-term debt	(34,404)	(55,641)
Net proceeds from issuance of common stock	6,666	5
Repayment of capital lease obligation	(378)	(262)
Dividend distribution to noncontrolling interest	(3,282)
Other	308
Net cash and cash equivalents used in financing activities	(23,409)	(57,199)
Effect of exchange rate changes on cash and cash equivalents	6,274	(375)
Change in cash and cash equivalents	18,803	(25,881)
Cash and cash equivalents, beginning of period	247,802	218,435
Cash and cash equivalents, end of period	266,605	192,554
Non-cash financing activities:
Increase in Accounts Payable related to the purchase of Property, plant and equipment	$ (13,840)	$ (1,925)