Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021		Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 52,129		$ 35,742
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	44,319		42,575
Operatingleaserightofuseassetamortization	4,780		4,527
Provision for doubtful accounts	342		162
Provision for warranty and returns	(345)		(1,221)
Stock compensation	12,703		12,349
Loss on disposal of property and equipment	829		1,078
Bond premium amortization	364		85
Debt Issuance Costs amortization	144		144
Change in fair value of contingent earn-out	0		2,700
Inventory Recall Expense	0		2,626
Sparepartsusage	5,356		5,045
Other Noncash Income (Expense)	1,574		1,615
Cash provided by (used in) changes in operating assets and liabilities
Accounts receivable	2,078		5,293
Inventories	13,368		8,481
Prepaid expenses and other assets	759		(9,333)
Increase (Decrease) in Other Operating Assets	(7,632)		(7,223)
Accounts payable	(1,648)		(23,305)
Accrued liabilities	(17,068)		(15,257)
Income taxes, including excess tax benefits and deferred income taxes	(5,970)		2,657
Net cash provided by operating activities	106,082		68,740
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(29,693)		(38,517)
Proceeds from sale of asset	203		147
Intangible assets additions	(4,136)		(4,104)
Purchases of investment securities	(10,034)		(7,082)
Proceeds from sale of investment securities	7,000		16,400
Net cash used in investing activities	(36,660)		(33,156)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Lines of Credit	0		150,000
Proceeds from exercise of stock options	5,416		6,799
Finance Lease, Principal Payments	(296)		(116)
Payment, Tax Withholding, Share-based Payment Arrangement	7,819		12,561
Net cash (used in) provided by financing activities	(2,699)		144,122
Effect of exchange rate changes on cash	(783)		(2,242)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	65,940		177,464
CASH AND CASH EQUIVALENTS, beginning of period	396,097	[1]	268,670
CASH AND CASH EQUIVALENTS, end of period	462,037		446,134
NON-CASH INVESTING ACTIVITIES
Capital Expenditures Incurred but Not yet Paid	$ 1,857		$ 9,775

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