Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities
Net income	$ 23,438	$ 4,885
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	2,432	2,061
Deferred taxes	(2,910)	480
Stock-based compensation expense	2,580	2,079
Provision for excess and obsolete inventory	1,014	815
Changes in operating assets & liabilities:
Accounts receivable	2,699	(26,448)
Inventories	(7,527)	(1,540)
Prepaid expenses and other current assets	(4,253)	(3,054)
Accounts payable and other current liabilities	10,788	3,721
Deferred revenue	3,859	5,875
Income taxes	7	50
Other assets and liabilities	(730)	(5,627)
Net cash provided by (used in) operating activities	31,397	(16,703)
Cash flows from investing activities
Expenditures for property, plant and equipment	(1,849)	(1,859)
Net cash used in investing activities	(1,849)	(1,859)
Cash flows from financing activities
Net settlement on restricted stock grants	(1,134)	(2)
Financing fees and other expenses		(117)
Proceeds from Employee Stock Purchase Plan	349
Proceeds from exercise of stock options	9,290	556
Net cash provided by financing activities	8,505	437
Effect of exchange rate changes on cash and cash equivalents	(357)	143
Net increase (decrease) in cash, cash equivalents and restricted cash	37,696	(17,982)
Cash, cash equivalents and restricted cash at beginning of period	77,655	85,825
Cash, cash equivalents and restricted cash at end of period	$ 115,351	$ 67,843