CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
OPERATING ACTIVITIES:
Net (loss) income	$ (39,964,000)	$ 629,000	$ (62,147,000)
Adjustments to reconcile net (loss) income to net cash used by operating activities:
Depreciation and amortization	13,396,000	14,239,000	18,516,000
Stock-based compensation	11,456,000	8,314,000	11,071,000
Provision for bad debts (net of recoveries)	176,000	440,000	2,090,000
Loss on disposal of assets	218,000	383,000	2,639,000
Provision for excess and obsolete inventory	2,297,000	1,349,000	16,886,000
Impairment of goodwill	0	0	21,233,000
Impairment of acquired intangibles	0	0	10,548,000
Impairment of loan to affiliate	0	0	549,000
Deferred income tax expense (benefit)	24,706,000	(28,444,000)	(6,304,000)
(Increase) decrease in:
Accounts receivable, net	(15,577,000)	12,346,000	10,406,000
Inventories	(6,706,000)	10,343,000	(4,136,000)
Prepaid expenses and other assets	5,996,000	3,862,000	1,188,000
(Decrease) increase in:
Accounts payable and accrued liabilities	(13,260,000)	2,390,000	(2,518,000)
Income taxes payable	847,000	(3,357,000)	1,041,000
Customer deposits	2,627,000	(374,000)	(30,000)
Unearned service revenues	312,000	(726,000)	11,436,000
Net cash (used in) provided by operating activities	(13,476,000)	21,394,000	32,468,000
INVESTING ACTIVITIES:
Purchases of investments	0	0	(50,000,000)
Proceeds from sale of investments	0	25,000,000	50,000,000
Purchases of property and equipment	(7,035,000)	(4,774,000)	(6,675,000)
Cash paid for technology development, patents and licenses	(4,905,000)	(1,298,000)	(2,118,000)
Acquisition of business, net of cash received	(33,800,000)	(6,036,000)	0
Other	0	1,015,000	(549,000)
Net cash (used in) provided by investing activities	(45,740,000)	13,907,000	(9,342,000)
FINANCING ACTIVITIES:
Payments on capital leases	(296,000)	(338,000)	(358,000)
Payments of contingent consideration for acquisitions	0	(733,000)	(3,101,000)
Payment, Tax Withholding, Share-based Payment Arrangement	(4,002,000)	(2,602,000)	(2,199,000)
Proceeds from issuance of stock related to stock option exercises	5,880,000	14,731,000	7,901,000
Net cash provided by financing activities	1,582,000	11,058,000	2,243,000
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(6,010,000)	5,640,000	(518,000)
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(63,644,000)	51,999,000	24,851,000
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	185,633,000	133,634,000	108,783,000
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 121,989,000	$ 185,633,000	$ 133,634,000