Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net loss	$ (23,399)	$ (18,461)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,274	1,537
Stock-based compensation	2,357	1,884
Change in fair value of contingent consideration related to acquisition	13,690	8,600
Gain on sale of equipment	0	(141)
Changes in operating assets and liabilities:
Accounts receivable	(2,279)	(348)
Other receivables	(26)	336
Inventories	(1,681)	(5,044)
Prepaid expenses and other current assets	(961)	(291)
Accounts payable	(1,557)	733
Accrued payroll	(385)	543
Accrued expenses and other current liabilities	1,293	857
Deferred rent	(8)	0
Net cash used in operating activities	(11,682)	(9,795)
Cash flows from investing activities:
Purchases of property and equipment	(952)	(1,011)
Net cash used in investing activities	(952)	(1,011)
Cash flows from financing activities:
Proceeds from sale of stock, net of expenses	40,118	0
Proceeds from sale of common stock under employee stock purchase plan	1,409	1,053
Proceeds from exercise of stock options	2,126	2,468
Repayments of long-term debt	0	(41)
Net cash provided by financing activities	43,653	3,480
Effect of exchange rate changes on cash and cash equivalents	138	0
Net decrease in cash and cash equivalents	31,157	(7,326)
Cash and cash equivalents, beginning of period	20,035	38,191
Cash and cash equivalents, end of period	$ 51,192	$ 30,865