Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income	$ 35,279	$ 7,036
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	3,752	3,193
Gain on sale of equipment		(162)
Deferred taxes	(2,076)	465
Stock-based compensation expense	4,325	3,930
Provision for doubtful accounts		106
Provision for excess and obsolete inventory	1,547	1,142
Changes in operating assets & liabilities:
Accounts receivable	(18,374)	(7,898)
Inventories	(8,237)	(7,534)
Prepaid expenses and other current assets	(1,645)	(58)
Accounts payable and other current liabilities	21,345	(4,120)
Deferred revenue	5,353	(704)
Income taxes	34	85
Other assets and liabilities	(981)	(8,494)
Net cash provided by (used in) operating activities	40,322	(13,013)
Cash flows from investing activities
Proceeds from sale of equipment		162
Expenditures for property, plant and equipment and capitalized software	(6,910)	(2,261)
Net cash used in investing activities	(6,910)	(2,099)
Cash flows from financing activities
Net settlement on restricted stock grants	(1,134)	(2)
Financing fees and other expenses		(146)
Proceeds from Employee Stock Purchase Plan	349
Proceeds from exercise of stock options	11,112	1,737
Net cash provided by financing activities	10,327	1,589
Effect of exchange rate changes on cash and cash equivalents	(706)	186
Net increase (decrease) in cash, cash equivalents and restricted cash	43,033	(13,337)
Cash, cash equivalents and restricted cash at beginning of period	77,655	85,825
Cash, cash equivalents and restricted cash at end of period	$ 120,688	$ 72,488