CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities
Net income (loss)	$ 6,639	$ (4,231)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation expense	767	603
Amortization of intangible assets	934	325
Provision for doubtful accounts	119	71
Investment premium amortization	130
Stock-based compensation	1,823	1,849
Tax benefit from business acquisition	(9,824)
Changes in assets and liabilities:
Accounts receivable	1,576	1,716
Inventories	(6,497)	(3,389)
Prepaid expenses and other current assets	(1,175)	(375)
Other assets	(137)	47
Accounts payable	2,383	519
Accrued liabilities	(523)	(1,049)
Deferred revenue	202	86
Other long-term liabilities	(18)	(347)
Net cash used in operating activities	(3,601)	(4,175)
Investing activities
Purchases of available-for-sale investments		(25,500)
Proceeds from maturities of available-for-sale investments	20,362	24,095
Purchases of property and equipment	(432)	(808)
Business acquisitions, net of cash acquired	(32,155)	(8,380)
Net cash used in investing activities	(12,225)	(10,593)
Financing activities
Proceeds from exercise of options for common stock	116	491
Repurchase of common stock	(1,737)
Repayment of notes payable	(194)	(267)
Proceeds from revolving credit facility	5,000
Payment of debt issuance costs	(89)
Net cash provided by financing activities	3,096	224
Effect of exchange rate changes on cash and cash equivalents	204	(6)
Net decrease in cash and cash equivalents	(12,526)	(14,550)
Cash and cash equivalents at beginning of period	29,530	29,187
Cash and cash equivalents at end of period	17,004	14,637
Supplemental disclosure of cash flow information
Cash paid for interest	30	36
Cash paid for taxes	190	66
Supplemental schedule of non-cash investing and financing activities
Landlord paid tenant improvements		53
Net unrealized losses on available-for-sale investments	$ 74	$ 40