Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net income	$ 35,308	$ 7,322
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	7,346	5,583
Deferred income taxes	5,399	818
Stock-based compensation expense	7,727	6,140
Provision for excess and obsolete inventory	2,736	1,961
Changes in operating assets & liabilities:
Accounts receivable	39,109	29,232
Inventories	(18,611)	(16,602)
Prepaid expenses and other current assets	(2,704)	(155)
Accounts payable and other current liabilities	10,540	(22,887)
Deferred revenue	(12,292)	4,864
Income taxes	29	(185)
Other assets and liabilities	1,080	(16,436)
Net cash provided by (used in) operating activities	75,667	(345)
Cash flows from investing activities
Expenditures for property, plant and equipment and capitalized software	(5,567)	(11,064)
Net cash used in investing activities	(5,567)	(11,064)
Cash flows from financing activities
Net settlement on restricted stock grants	(3,888)	(1,602)
Repurchase of common stock	(7,501)	(14,035)
Proceeds from Employee Stock Purchase Plan	509	407
Principal payments on finance lease obligation	(252)
Proceeds from exercise of stock options	7,740	3,039
Net cash used in financing activities	(3,392)	(12,191)
Effect of exchange rate changes on cash and cash equivalents	(525)	871
Net increase (decrease) in cash, cash equivalents and restricted cash	66,183	(22,729)
Cash, cash equivalents and restricted cash at beginning of period	146,534	184,902
Cash, cash equivalents and restricted cash at end of period	$ 212,717	$ 162,173