Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income (loss)	$ 41,802	$ 1,531	$ (19,305)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	2,423	1,824	1,729
Stock-based compensation	13,219	9,383	6,660
Deferred income tax (benefit) expense	(40,405)	(19)	19
Amortization of investment premium, net	89	221	343
Provision for (recovery of) doubtful accounts receivable	859	324	(12)
Provision for excess and obsolete inventory	270	853	262
Loss on disposal and write-off of property and equipment	6	46	2
Changes in operating assets and liabilities:
Accounts receivable	(12,920)	(11,219)	(3,064)
Inventory	(12,941)	(6,898)	2,225
Prepaid expenses and other assets	(5,338)	(2,419)	(693)
Deferred revenue	2,254	2,908	267
Accounts payable, accrued and other liabilities	18,425	2,609	7,486
Net cash provided by (used in) operating activities	7,743	(856)	(4,081)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of investments	(16,024)	(13,444)	(31,591)
Proceeds from sale of investments	0	1,000	11,143
Proceeds from maturity of investments	20,654	21,393	25,528
Purchase of property and equipment	(4,279)	(2,340)	(834)
Change in restricted cash	94	(252)	138
Net cash provided by investing activities	445	6,357	4,384
Net Cash Provided by (Used in) Financing Activities [Abstract]
Principal payments on capital leases	(120)	0	0
Proceeds from issuance of common stock upon exercise of stock options	6,628	4,319	3,438
Tax payments related to shares withheld for vested restricted stock units	(8,283)	(6,594)	(876)
Tax effect of employee stock plans	1,357	87	0
Net cash provided by (used in) financing activities	(418)	(2,188)	2,562
Effect of exchange rate on cash and cash equivalents	(709)	(462)	57
NET INCREASE IN CASH AND CASH EQUIVALENTS	7,061	2,851	2,922
CASH AND CASH EQUIVALENTS—Beginning of period	28,649	25,798	22,876
CASH AND CASH EQUIVALENTS—End of period	$ 35,710	$ 28,649	$ 25,798