CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net income (loss)	$ 443	$ (127,996)	$ (30,768)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	29,421	30,381	32,389
Stock-based compensation expense	10,363	14,895	12,914
Impairments	0	0	7,719
Restructuring and other charges	7,829	75,214	35,380
Gain on sale of property, plant and equipment	(20,019)	(4,482)	(587)
Deferred income taxes	6,401	(8,701)	4,950
Changes in operating assets and liabilities:
Trade receivables, net	8,420	13,469	(9,522)
Unbilled receivables	(43,077)	37,721	216
Inventories, net	(1,151)	(5,482)	(28,290)
Prepaids and other assets	(14,466)	10,650	(24,930)
Accounts payable and accrued expenses	(20,768)	3,015	(20,387)
Other, net	(167)	(256)	(172)
Net cash provided by (used in) operating activities	(36,771)	38,428	(21,088)
Investing activities
Purchase of property, plant and equipment	(18,866)	(9,990)	(11,943)
Proceeds from sale of property, plant and equipment	20,993	6,783	6,315
Purchase of short-term investments	(32,232)	0	0
Net cash used in investing activities	(30,105)	(3,207)	(5,628)
Financing activities
Repurchase of common shares	(20,807)	(24,191)	(25,000)
Other	(83)	(109)	(183)
Net cash used in financing activities	(20,890)	(24,300)	(25,183)
Effect of exchange rate changes on cash activities	(2,881)	(1,425)	(1,092)
Increase (decrease) in cash and cash equivalents	(90,647)	9,496	(52,991)
Cash and cash equivalents at beginning of year	355,451	345,955	398,946
Cash and cash equivalents at end of year	$ 264,804	$ 355,451	$ 345,955