Condensed Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities
Net (loss) income	$ (10,465,000)	$ 2,893,000	$ (2,479,000)
Depreciation, Depletion and Amortization	2,542,000	2,615,000	2,010,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Non-cash interest income	(71,000)	(18,000)	0
Loss on disposal of property and equipment	0	27,000	0
Bad debt expense (recovery)	16,000	0	(10,000)
Inventory write-down	136,000	224,000	563,000
Change in lease-related performance liabilities	(207,000)	(3,000)	0
Share-based Compensation	8,667,000	4,232,000	1,458,000
Excess tax benefits from employee stock plans	0	(325,000)	0
Change in fair value of warrant liability	0	1,631,000	981,000
Change in fair value of option liability	0	0	450,000
Changes in assets and liabilities
Accounts receivable	(1,861,000)	(5,916,000)	(6,670,000)
Other receivables	(434,000)	417,000	(74,000)
Inventories	(3,029,000)	367,000	(1,103,000)
Prepaid expenses /OCA - DO NOT USE	446,000	(1,348,000)	(263,000)
Accounts payable	690,000	(1,145,000)	2,969,000
Increase (Decrease) in Other Operating Liabilities	(1,887,000)	2,803,000	1,379,000
Deferred revenue	4,198,000	5,840,000	6,301,000
Net cash (used in) provided by operating activities	(1,259,000)	12,294,000	5,512,000
Cash flows from investing activities
Payment for purchase of property and equipment	(3,770,000)	(2,565,000)	(2,392,000)
Purchase of short-term investments	(118,661,000)	(104,869,000)	0
Maturities of short-term investments	65,714,000	69,902,000	0
Changes in restricted cash	0	0	(62,000)
Net cash used in investing activities	(56,717,000)	(37,532,000)	(2,454,000)
Cash flows from financing activities
Cash from lease-related performance obligations	847,000	1,114,000	0
Proceeds from borrowings	0	0	4,500,000
Principal payment of borrowings	0	(8,333,000)	(1,572,000)
Proceeds from initial public offering, net of offering costs	0	72,070,000	0
Proceeds from secondary public offering, net of offering costs	0	35,975,000	0
Payment for repurchase of common stock	(14,000)	(10,000)	(4,000)
Excess tax benefits from employee stock plans	0	325,000	0
Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Excluding Stock Options	2,993,000	0	0
Proceeds from exercise of stock options	1,758,000	1,720,000	1,811,000
RSUs released and tax settlement	(703,000)	0	0
Proceeds from Warrant Exercises	226,000	0	0
Proceeds from preferred stock warrants	0	0	2,000
Common stock issuance costs	0	0	(1,539,000)
Net cash provided by financing activities	5,107,000	102,861,000	3,198,000
Net (decrease) increase in cash and cash equivalents	(52,869,000)	77,623,000	6,256,000
Cash and cash equivalents at beginning of period	92,521,000	14,898,000	8,642,000
Cash and cash equivalents at end of period	39,652,000	92,521,000	14,898,000
Supplemental cash flow information
Cash paid for interest	0	91,000	314,000
Cash paid for income taxes	54,000	556,000	0
Supplemental disclosure of non-cash investing and financing activities
Costs related to the initial public offering in accounts payable and accrued liabilities	0	0	86,000
Property and equipment in accounts payable and accrued liabilities	$ 104,000	$ 321,000	$ 165,000