Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Consolidated net income	$ 56,629	$ 17,922	$ 14,109
Adjustments to reconcile consolidated net income to net cash provided by operating activities:
Depreciation and amortization	11,705	11,056	10,334
Stock-based compensation expense	7,035	5,883	3,036
(Decrease) increase in long-term deferred revenue	(320)	(321)	822
(Decrease) increase in long-term income taxes payable	(74)	76	329
Deferred income taxes	18	(21)	60
Provision (recovery) for doubtful accounts	0	23	(144)
Credit gain on available-for-sale securities	(4)	(4)	(4)
(Decrease) increase in contingent consideration obligations	(74)	0	280
(Decrease) increase in other assets	(43)	182	(35)
Change in current assets and liabilities, net	(20,428)	(54)	(6,576)
Net cash provided by operating activities	54,444	34,742	22,211
Investing activities:
Purchases of short-term investments	(70,900)	(50,166)	0
Additions to property, plant and equipment	(47,761)	(28,653)	(12,485)
Sales and maturities of short-term investments	75,000	0	0
Net cash used for investing activities	(43,661)	(78,819)	(12,485)
Financing activities:
Proceeds from employee stock plans	10,243	11,585	4,742
Proceeds from public offering of Common Stock	0	109,681	0
Payment of contingent consideration obligations	(153)	(224)	(237)
Noncontrolling interest dividend paid	0	0	(139)
Net cash provided by financing activities	10,090	121,042	4,366
Effect of foreign exchange rates on cash	(197)	109	19
Net increase in cash and cash equivalents	20,676	77,074	14,111
Cash and cash equivalents at beginning of year	161,742	84,668	70,557
Cash and cash equivalents at end of year	182,418	161,742	84,668
Change in current assets and liabilities:
Accounts receivable	(14,301)	(2,816)	5,714
Inventories, net	(10,134)	(8,049)	(1,812)
Other current assets	10	369	(2,895)
Accounts payable and accrued liabilities	2,503	8,668	(7,339)
Accrued severance and other charges	93	0	(234)
Short-term lease payable	4	34	12
Income taxes payable	(73)	82	(653)
Deferred revenue	1,470	1,658	631
Change in current assets and liabilities, net	(20,428)	(54)	(6,576)
Supplemental disclosures:
Cash paid during the year for income taxes, net of refunds	$ 645	$ 79	$ 2,194