CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flow from operating activities:
Net Income (Loss)	$ 604	$ (1,624)	$ (128,493)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	30,324	29,421	30,381
Stock-based compensation expense	10,892	10,363	14,895
Restructuring and other charges	(2,042)	7,829	75,214
Gain on sale of property, plant and equipment	(8,754)	(20,019)	(4,482)
Acquisition costs	3,381	0	0
Deferred income taxes	(2,867)	6,401	(8,701)
Changes in operating assets and liabilities:
Trade receivables, net	(25,839)	8,566	13,966
Unbilled receivables	(3,245)	(43,077)	37,721
Inventories, net	(28,635)	(1,151)	(5,482)
Prepaids and other assets	30,751	(12,545)	10,650
Accounts payable and accrued expenses	4,210	(20,768)	3,015
Other, net	(1,053)	(167)	(256)
Net cash provided by (used in) operating activities	7,727	(36,771)	38,428
Cash flows from investing activities:
Purchase of property, plant and equipment	(32,626)	(18,866)	(9,990)
Proceeds from sale of property, plant and equipment	28,776	20,993	6,783
Acquisition of Great North, net of cash acquired	(82,287)	0	0
Purchase of short-term investments	(48,866)	(32,232)	0
Maturities of short-term investments	55,190	0	0
Net cash used in investing activities	(79,813)	(30,105)	(3,207)
Cash flows from financing activities:
Repurchase of common shares	0	(20,807)	(24,191)
Other	(124)	(83)	(109)
Net cash used in financing activities	(124)	(20,890)	(24,300)
Effect of exchange rate changes on cash activities	(1,194)	(2,881)	(1,425)
Increase (decrease) in cash and cash equivalents	(73,404)	(90,647)	9,496
Cash and cash equivalents at beginning of year	264,804	355,451	345,955
Cash and cash equivalents at end of year	$ 191,400	$ 264,804	$ 355,451