CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities
Net income (loss)	$ (6,763)	$ 28,840
Adjustments to reconcile net income (loss) to cash used in operating activities:
Depreciation	295	379
Charge for 401(k) company common stock match	180	162
Stock-based compensation	863	1,104
Changes in operating assets and liabilities:
Accounts receivables	62	87
Due from related party	75	175
Unbilled receivables	(561)	(240)
Inventory	(420)	(2,977)
Prepaid expenses and other assets	(18)	114
Accounts payable	(1,141)	(323)
Accrued expenses	(937)	(885)
Deferred rent and other long-term liabilities	(38)	(39)
Deferred revenue	(95)	(38,656)
Net cash used in operating activities	(8,498)	(12,259)
Cash flows from investing activities
Purchase of property and equipment	(64)	(148)
Purchase of short-term investments	(5,015)	(28,240)
Proceeds from the sale and maturity of short-term investments	19,520	28,961
Net cash provided by investing activities	14,441	573
Cash flows from financing activities
Proceeds from options exercised	5	11
Net cash provided by financing activities	5	11
Effect of exchange rate changes on cash and cash equivalents	(8)	2
Net increase (decrease) in cash and cash equivalents	5,940	(11,673)
Cash and cash equivalents at beginning of period	14,572	21,277
Cash and cash equivalents at end of period	$ 20,512	$ 9,604