Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities
Net income	$ 58,758	$ 79,009	$ 53,711
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,343	25,634	22,766
Amortization of debt issuance costs	43	43	7
Amortization of right of use assets	73	0	0
Provision for credit losses on accounts receivable, net of adjustments	43	153	91
Provision for excess and obsolete inventories	629	1,108	1,454
Share-based compensation	11,812	11,342	11,799
(Gain) loss on disposition of assets and insurance recoveries	(21)	(6,478)	337
Foreign currency transaction gain	(1)	(12)	(27)
Interest income on note receivable	(24)	(24)	(25)
Deferred income taxes	3,669	13,027	6,038
Changes in assets and liabilities:
Accounts receivable	(9,737)	19,859	(13,412)
Income tax receivable	(1,136)	(3,815)	5,129
Inventories	(45,955)	(9,726)	2,557
Contract assets	1,886	0	0
Prepaid expenses and other	1,374	(2,364)	(329)
Accounts payable	10,899	(2,155)	280
Contract liabilities	(229)	0	0
Deferred revenue	447	1,010	425
Accrued liabilities and donations	(1,690)	2,203	7,124
Net cash provided by operating activities	61,183	128,814	97,925
Investing Activities
Capital expenditures	(55,362)	(67,802)	(37,166)
Cash paid in business combination, net of cash acquired	(103,430)	0	0
Proceeds from sale of property, plant and equipment	19	60	69
Insurance proceeds	0	6,417	0
Investment in certificates of deposits	0	0	(6,000)
Maturities of certificates of deposits	0	0	6,000
Principal payments from note receivable	54	52	51
Net cash used in investing activities	(158,719)	(61,273)	(37,046)
Financing Activities
Borrowings under revolving credit facility	40,000	0	0
Proceeds from financing obligation, net of issuance costs	0	0	6,614
Payment related to financing costs	0	0	(301)
Stock options exercised	21,148	21,418	12,625
Repurchase of stock	(20,876)	(30,060)	(19,586)
Employee taxes paid by withholding shares	(1,590)	(1,169)	(1,207)
Dividends paid to stockholders	(19,947)	(19,815)	(16,645)
Net cash provided by (used in) financing activities	18,735	(29,626)	(18,500)
Net (decrease) increase in cash, cash equivalents and restricted cash	(78,801)	37,915	42,379
Cash, cash equivalents and restricted cash, beginning of year	82,288	44,373	1,994
Cash, cash equivalents and restricted cash, end of year	$ 3,487	$ 82,288	$ 44,373