CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities
Net loss	$ (33,840)	$ (4,369)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	16,813	16,851
Stock-based compensation expense	6,458	8,083
Impairments	7,719
Restructuring and other charges	34,300	314
Gain on sale of assets	(552)	(1,203)
Deferred income taxes	(2,421)	164
Changes in operating assets and liabilities:
Trade receivables, net	(104)	7,621
Unbilled receivables	(467)	(24,337)
Inventories, net	(33,869)	(1,002)
Prepaids and other assets	(23,452)	5,860
Accounts payable and accrued expenses	11,224	2,731
Other, net		(63)
Net cash provided by (used in) operating activities	(18,191)	10,650
Investing activities
Purchase of property, plant and equipment	(8,318)	(4,598)
Proceeds from sale of equipment	3,138	1,565
Net cash used in investing activities	(5,180)	(3,033)
Financing activities
Repurchase of common shares	(25,000)	(1,996)
Other	(129)
Net cash used in financing activities	(25,129)	(1,996)
Effect of exchange rate changes on cash activities	(4,638)	(595)
Increase (decrease) in cash and cash equivalents	(53,138)	5,026
Cash and cash equivalents at beginning of period	398,946	418,100
Cash and cash equivalents at end of period	$ 345,808	$ 423,126