Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net Income	$ 8,797	$ 6,132
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,392	921
Loss on disposal of property and equipment	1	1
Amortization of stock-based compensation	1,247	691
Provision for inventory reserves	191	364
Deferred tax assets	2,792
Changes in assets and liabilities:
Accounts receivable	(3,348)	(3,214)
Inventories	1,241	(2,780)
Prepaid expenses and other current assets	199	(548)
Other assets	18	37
Accounts payable	(271)	3,961
Accrued expenses	1,461	984
Other long-term liabilities	22	(28)
Net cash provided by operating activities	13,742	6,521
Cash flows from investing activities:
Purchase of short-term investments	(18,911)	(9,297)
Proceeds from sales and maturities of short-term investments	14,826	9,976
Purchase of long-term investments	(90)	(89)
Purchase of property and equipment	(2,678)	(1,740)
Net cash used in investing activities	(6,853)	(1,150)
Cash flows from financing activities:
Proceeds from issuance of stock under ESPP	340	235
Proceeds from the exercise of common stock options	248	1,608
Tax payments related to net share settlements of RSUs	(2,211)	(241)
Repurchase of common stock		(873)
Net cash (used in) provided by financing activities	(1,623)	729
Effect of exchange rate changes on cash and cash equivalents	(65)	(255)
Net increase in cash and cash equivalents	5,201	5,845
Cash and cash equivalents at beginning of period	18,603	4,793
Cash and cash equivalents at end of period	23,804	10,638
Supplemental disclosure of cash flow information:
Cash paid for income tax	$ 735	$ 202