Consolidated Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities:
Net income	$ 73,386	$ 25,697
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29,430	30,777
Deferred income taxes	3,867	3,583
Non-cash stock based compensation	9,422	6,569
Change in defined benefit pension plans	(650)	(433)
Loss on disposition of property and equipment	638	562
Gain on sale of patents		(1,978)
Changes in assets and liabilities:
Accounts receivable, net	26,162	(33,250)
Inventory	(34,019)	4,645
Other assets	10	(57)
Accounts payable	9,231	24,272
Other liabilities	(371)	12,914
Net cash provided by operating activities	117,106	73,301
Investing Activities:
Purchases of property and equipment	(29,585)	(11,613)
Acquisition of intangible assets		(3,141)
Proceeds from the sale of patents and property and equipment	11	1,068
Acquisition of business	(2,827)
Cost of technology investments	(7,557)
Net cash used in investing activities	(39,958)	(13,686)
Financing Activities:
Borrowing of debt		201,193
Repayments of debt	(151,993)	(87,688)
Cash paid for the repurchase of Common Stock		(9,092)
Proceeds from the exercise of Common Stock options	7,467	6,828
Cash paid for the cancellation of restricted stock	(3,991)	(811)
Acquisition contingent consideration payment	(69)	(618)
Net cash (used in) provided by financing activities	(148,586)	109,812
Foreign currency effect	(1,821)	6,664
Net (decrease) increase in cash, cash equivalents and restricted cash	(73,259)	176,091
Cash, cash equivalents and restricted cash at beginning of period	268,345	52,948
Cash, cash equivalents and restricted cash at end of period	195,086	229,039
Supplemental disclosure of cash flow information:
Cash paid (refund) for taxes	12,348	(252)
Cash paid for interest	$ 1,823	$ 3,006