CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities
Net cash provided by operating activities	$ 41,860	$ 52,951
Cash flows from investing activities
Decrease (increase) in restricted cash	36	(2,611)
Purchases of property, plant and equipment	(29,072)	(46,877)
Proceeds from sales of property, plant, and equipment	19	19
Purchase of equity securities	(49)	(3,241)
Purchases of short-term investments	(13,238)	(35,095)
Proceeds from maturity of short-term investments	32,771	21,135
Other	(634)	(94)
Net cash and cash equivalents used in investing activities	(10,167)	(66,764)
Cash flows from financing activities
Advances on lines of credit and short-term debt		1,449
Taxes paid related to net share settlement	(2,494)
Repayments on lines of credit and short-term debt		(1,550)
Debt issuance costs	(307)
Proceeds from long-term debt	1,500
Repayments of long-term debt	(55,641)	(41,145)
Net proceeds from issuance of common stock		8,274
Repayment of capital lease obligation and other	(257)	(139)
Net cash and cash equivalents used in financing activities	(57,199)	(33,111)
Effect of exchange rate changes on cash and cash equivalents	(375)	(1,484)
Decrease in cash and cash equivalents	(25,881)	(48,408)
Cash and cash equivalents, beginning of period	218,435	243,000
Cash and cash equivalents, end of period	192,554	194,592
Non-cash financing activities:
Property, plant and equipment purchased on accounts payable	$ (1,925)	$ (18,963)