CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net (loss) income	$ (14,823)	$ 152
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	3,759	4,749
Stock-based compensation	2,178	2,564
Provisions for bad debts, net of recoveries	(15)	(100)
Loss on disposal of assets	10	57
Provision for excess and obsolete inventory	204	896
Deferred income tax benefit	(2,326)	8
Decrease (Increase) in:
Accounts receivable	16,084	12,410
Inventories	1,795	(10,908)
Prepaid expenses and other current assets	7,408	4,463
(Decrease) Increase in:
Accounts payable and accrued liabilities	4,756	(9,172)
Income taxes payable	(1,389)	(1,323)
Net cash provided by operating activities	16,315	5,810
Investing activities:
Purchases of property and equipment	(757)	(1,543)
Proceeds from sale of investments	9,000	0
Payments for intangible assets	(435)	(529)
Net cash provided by (used in) investing activities	7,808	(2,072)
Financing activities:
Payments on finance leases	(82)	(90)
Payments of contingent consideration for acquisitions	0	(250)
Payments for taxes related to net share settlement of equity awards	(1,581)	(1,138)
Proceeds from issuance of stock related to stock option exercises	2,802	292
Net cash provided by (used in) financing activities	1,139	(1,186)
Effect of exchange rate changes on cash and cash equivalents	(1,656)	(639)
Increase in cash and cash equivalents	23,606	1,913
Cash and cash equivalents, beginning of period	133,634	108,783
Cash and cash equivalents, end of period	157,240	110,696
Customer deposits
(Decrease) Increase in:
Increase (decrease) in contract with customer, liability	(961)	(310)
Current portion of unearned service revenues
(Decrease) Increase in:
Increase (decrease) in contract with customer, liability	$ (365)	$ 2,324