Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities
Net income (loss)	$ 2,082	$ (2,242)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	1,276	521
Amortization of intangible assets	656	755
Non-cash interest income	(39)	0
Loss on disposal of property and equipment	2	0
Bad debt expense	0	44
Inventory write-down	207	18
Stock-based compensation expense	2,642	566
Non-employee stock-based compensation expense	29	455
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Operating Activities	(300)	0
Change in fair value of warrant liability	1,631	915
Change in fair value of option liability	0	413
Changes in assets and liabilities
Accounts receivable	(4,862)	(7,539)
Other assets	638	(244)
Inventories	(72)	71
Prepaid expenses and other current assets	(937)	(660)
Other long term assets	(14)	(258)
Accounts payable	(1,231)	102
Accrued liabilities	1,489	869
Warranty reserve	(390)	185
Other long term liabilities	3	18
Deferred revenue	3,004	4,446
Net cash provided by (used in) operating activities	5,814	(1,565)
Cash flows from investing activities
Purchase of property and equipment	(1,379)	(1,840)
Purchase of short-term investments	(87,383)	0
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities	13,986	0
Increase (Decrease) in Restricted Cash	0	(1)
Net cash used in investing activities	(74,776)	(1,841)
Cash flows from financing activities
Cash from lease-related performance obligations	713	0
Borrowings	0	4,500
Principal payments on long-term borrowings	(8,333)	(1,072)
Proceeds from initial public offering, net of offering costs	72,217	0
Proceeds from secondary public offering, net of offering costs	35,996	0
Payment for repurchase of early exercised options	(6)	0
Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Financing Activities	300	0
Proceeds from exercise of stock options	863	1,878
Proceeds from exercise of preferred stock warrants	0	0
Common stock issuance costs	0	(1,407)
Net cash provided by financing activities	101,750	3,899
Net increase in cash and cash equivalents	32,788	493
Cash and cash equivalents at beginning of period	14,898	8,642
Cash and cash equivalents at end of period	47,686	9,135
Supplemental disclosure of non-cash investing and financing activities
Costs related to the initial public offering in accounts payable and accrued liabilities	190	138
Property and equipment in accounts payable and accrued liabilities	$ 0	$ 33