Consolidated Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities:
Net income	$ 57,700	$ 1,551
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,571	20,488
Deferred income taxes	(225)	(913)
Non-cash stock based compensation	6,199	3,909
Change in defined benefit pension plans	(669)	(278)
Loss on disposition of property and equipment	496	339
Operating lease expense	4,629	3,490
Gain on sale of patents		(1,978)
Changes in assets and liabilities:
Accounts receivable, net	11,647	38,410
Inventory	(17,211)	5,292
Other assets	3,986	2,888
Accounts payable	(289)	(17,753)
Other liabilities	(1,472)	(5,218)
Net cash provided by operating activities	84,362	50,227
Investing Activities:
Purchases of property and equipment	(20,669)	(7,500)
Acquisition of intangible assets		(3,141)
Proceeds from the sale of patents and property and equipment	10	1,061
Cost of technology investment	(5,200)
Net cash used in investing activities	(25,859)	(9,580)
Financing Activities:
Borrowing of debt		201,193
Repayments of debt	(143,731)	(81,830)
Cash paid for the repurchase of Common Stock		(9,092)
Proceeds from the exercise of Common Stock options	6,292	6,178
Cash paid for the cancellation of restricted stock	(2,117)	(471)
Acquisition contingent consideration payment	(69)
Net cash (used in) provided by financing activities	(139,625)	115,978
Foreign currency effect	(360)	2,102
Net (decrease) increase in cash, cash equivalents and restricted cash	(81,482)	158,727
Cash, cash equivalents and restricted cash at beginning of period	268,345	52,948
Cash, cash equivalents and restricted cash at end of period	186,863	211,675
Supplemental disclosure of cash flow information:
Cash paid (refund) for taxes	8,563	(3,117)
Cash paid for interest	$ 1,455	$ 1,967