Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021		Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 23,731		$ 16,834
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	22,155		20,957
Operatingleaserightofuseassetamortization	2,372		2,305
Provision for doubtful accounts	0		5
Provision for warranty and returns	209		(821)
Stock compensation	6,022		6,939
Loss on disposal of property and equipment	659		562
Bond premium amortization	168		34
Debt Issuance Costs amortization	72		72
Change in fair value of contingent earn-out	0		0
Inventory Recall Expense	0		2,626
Sparepartsusage	2,825		4,900
Other Noncash Income (Expense)	(1,287)		876
Cash provided by (used in) changes in operating assets and liabilities
Accounts receivable	1,506		899
Inventories	13,208		19,372
Prepaid expenses and other assets	(742)		2,634
Increase (Decrease) in Other Operating Assets	(3,463)		(6,402)
Accounts payable	2,411		(35,063)
Accrued liabilities	(19,965)		465
Income taxes, including excess tax benefits and deferred income taxes	1,439		2,325
Net cash provided by operating activities	51,320		39,519
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(14,028)		(25,463)
Proceeds from sale of asset	55		131
Intangible assets additions	(1,874)		(1,958)
Purchases of investment securities	(10,034)		(7,082)
Proceeds from sale of investment securities	7,000		10,900
Net cash used in investing activities	(18,881)		(23,472)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Lines of Credit	0		150,000
Proceeds from exercise of stock options	4,864		560
Finance Lease, Principal Payments	(141)		0
Payment, Tax Withholding, Share-based Payment Arrangement	7,723		12,174
Net cash (used in) provided by financing activities	(3,000)		138,386
Effect of exchange rate changes on cash	(1,287)		(3,546)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	28,152		150,887
CASH AND CASH EQUIVALENTS, beginning of period	396,097	[1]	268,670
CASH AND CASH EQUIVALENTS, end of period	424,249		419,557
NON-CASH INVESTING ACTIVITIES
Capital Expenditures Incurred but Not yet Paid	$ 1,068		$ 7,112

[1] December 31, 2020 balances were derived from audited consolidated financial statements.