CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income (loss)	$ (127,996)	$ (30,768)	$ 1,720
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	30,381	32,389	34,020
Release of contingent consideration	0	0	(2,001)
Stock-based compensation expense	14,895	12,914	15,721
Impairments	0	7,719	0
Restructuring and other charges	75,214	35,380	174
Gain on sale of property, plant and equipment	(4,482)	(587)	(1,511)
Deferred income taxes	8,701	4,950	598
Changes in operating assets and liabilities:
Trade receivables, net	13,469	(9,522)	10,783
Unbilled receivables	37,721	216	(57,032)
Inventories, net	(5,482)	(28,290)	(14,054)
Prepaids and other assets	10,650	(24,930)	10,980
Accounts payable and accrued expenses	3,015	(20,387)	15,343
Other, net	(256)	(172)	(63)
Net cash provided by (used in) operating activities	38,428	(21,088)	14,678
Investing activities
Purchase of property, plant and equipment	(9,990)	(11,943)	(11,501)
Proceeds from sale of equipment	6,783	6,315	3,030
Net cash used in investing activities	(3,207)	(5,628)	(8,471)
Financing activities
Proceeds from exercise of stock options	0	0	2,181
Repurchase of common shares	(24,191)	(25,000)	(26,570)
Other	(109)	(183)	(183)
Net cash used in financing activities	(24,300)	(25,183)	(24,572)
Effect of exchange rate changes on cash activities	(1,425)	(1,092)	(789)
Increase (decrease) in cash and cash equivalents	9,496	(52,991)	(19,153)
Cash and cash equivalents at beginning of year	345,955	398,946	418,100
Cash and cash equivalents at end of year	$ 355,451	$ 345,955	$ 398,946