Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
OPERATING ACTIVITIES
Net income	$ 53,912	$ 67,444
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	32,299	31,276
Amortization	3,018	3,598
Change in deferred taxes and other liabilities	1,787	2,596
Impairment of property, plant, equipment, and inventory	532	2,662
Non-cash interest expense	565	561
Compensation and benefits paid or payable in Class A Common Stock	2,274	2,447
Provision for credit losses from uncollected receivables and contract assets	493	1,326
Foreign currency remeasurement (gain) on intercompany loans	(3,198)	(1,260)
Fair value adjustment on foreign currency options	(123)	(381)
Changes in operating assets and liabilities that provided/(used) cash:
Accounts receivable	(40,131)	(14,407)
Contract assets	4,606	(23,868)
Inventories	(9,174)	(21,135)
Prepaid expenses and other current assets	(2,700)	(4,474)
Income taxes prepaid and receivable	(381)	(60)
Accounts payable	(5,255)	7,476
Accrued liabilities	(21,570)	(11,745)
Income taxes payable	(4,943)	(7,739)
Noncurrent receivables	1,705	1,864
Other noncurrent liabilities	(1,922)	(3,252)
Other, net	2,881	4,784
Net cash provided by operating activities	14,675	37,713
INVESTING ACTIVITIES
Purchases of property, plant and equipment	(34,899)	(35,659)
Purchased software	(72)	(366)
Net cash used in investing activities	(34,971)	(36,025)
FINANCING ACTIVITIES
Proceeds from borrowings	61,000	135,000
Principal payments on debt	(13,000)	0
Principal payments on finance lease liabilities	0	(654)
Purchase of Treasury shares	0	(84,780)
Taxes paid in lieu of share issuance	(3,136)	(770)
Proceeds from options exercised	0	7
Dividends paid	(15,570)	(13,399)
Net cash provided by financing activities	29,294	35,404
Effect of exchange rate changes on cash and cash equivalents	142	(18,258)
Increase in cash and cash equivalents	9,140	18,834
Cash and cash equivalents at beginning of period	291,776	302,036
Cash and cash equivalents at end of period	$ 300,916	$ 320,870