CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities
Net loss	$ (53,425)	$ (33,840)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	14,759	16,813
Stock-based compensation expense	6,265	6,458
Impairments		7,719
Restructuring and other charges	23,218	34,300
Gain on sale of assets	(3,873)	(552)
Deferred income taxes	(695)	(2,421)
Changes in operating assets and liabilities:
Trade receivables, net	26,450	(104)
Unbilled receivables	(5,082)	(467)
Inventories, net	(12,700)	(33,869)
Prepaids and other assets	14,375	(23,452)
Accounts payable and accrued expenses	15,123	11,224
Net cash provided by (used in) operating activities	24,415	(18,191)
Investing activities
Purchase of property, plant and equipment	(5,625)	(8,318)
Proceeds from sale of equipment	5,950	3,138
Net cash provided by (used in) investing activities	325	(5,180)
Financing activities
Repurchase of common shares		(25,000)
Other	(77)	(129)
Net cash used in financing activities	(77)	(25,129)
Effect of exchange rate changes on cash activities	(137)	(4,638)
Increase (decrease) in cash and cash equivalents	24,526	(53,138)
Cash and cash equivalents at beginning of period	345,955	398,946
Cash and cash equivalents at end of period	$ 370,481	$ 345,808