Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 63,327	$ 64,315	$ 68,229
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	35,911	34,368	33,339
Amortization	10,233	11,042	10,913
Stock-based compensation expense	13,366	15,286	18,485
Provision for doubtful accounts	671	1,321	489
Deferred income taxes	(5,928)	(14,992)	(7,248)
Asset impairments	0	1,075	0
Gain on the sale of property, plant and equipment	0	(101)	(289)
Gain on assets held for sale	0	0	(393)
Changes in operating assets and liabilities:
Accounts receivable	33,953	42,050	(136,455)
Contract assets	7,401	8,634	(28,370)
Inventories	127,840	45,071	(206,247)
Prepaid expenses and other assets	(8,159)	(4,648)	(6,467)
Accounts payable	(18,283)	(35,320)	(16,656)
Advance payments from customers	(61,269)	6,946	79,813
Accrued liabilities	(9,858)	(13,093)	6,303
Operating leases	131	2,414	441
Income taxes	(111)	9,926	6,646
Net cash provided by (used in) operating activities	189,225	174,294	(177,467)
Cash flows from investing activities:
Additions to property, plant and equipment	(31,306)	(73,479)	(43,357)
Additions to capitalized purchased software	(1,947)	(4,260)	(3,417)
Proceeds from the disposal of property, plant and equipment	2,007	649	321
Proceeds from the sale of assets held for sale	0	0	5,372
Other, net	(1,521)	(48)	(93)
Net cash used in investing activities	(32,767)	(77,138)	(41,174)
Cash flows from financing activities:
Borrowings under credit agreement	600,000	749,500	828,000
Principal payments on credit agreement	(674,102)	(743,602)	(633,000)
Dividends paid	(23,913)	(23,455)	(23,156)
Employee taxes paid with shares withheld	(6,292)	(5,761)	(3,201)
Proceeds from stock options exercised	482	129	716
Debt issuance costs	0	(216)	(574)
Principal payments on finance leases	(181)	(173)	(165)
Share repurchases	(5,100)	0	(9,391)
Net cash (used in) provided by financing activities	(109,106)	(23,578)	159,229
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(2,538)	2,205	(4,907)
Net increase (decrease) in cash, cash equivalents and restricted cash	44,814	75,783	(64,319)
Cash, cash equivalents and restricted cash at the beginning of the year	283,213	207,430	271,749
Cash, cash equivalents and restricted cash at the end of the year	328,027	283,213	207,430
Supplemental cash flow information:
Income taxes paid, net	46,727	37,659	28,478
Interest paid	28,032	30,551	11,627
Property, Plant and Equipment [Member]
Non-cash investing activities:
Unpaid purchases at the end of the period	5,025	1,558	23,734
Capitalized Purchased Software Costs [Member]
Cash flows from investing activities:
Additions to capitalized purchased software	(1,900)	(4,300)	(3,400)
Non-cash investing activities:
Unpaid purchases at the end of the period	$ 1,320	$ 0	$ 0