Condensed Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating Activities
Net income (loss)	$ (5,480)	$ (8,804)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	1,295	105
Amortization of Investments	(88)	133
Stock-based compensation	1,411	1,359
Changes in assets and liabilities:
Accounts receivable	(1,616)	1,935
Inventories	844	(1,158)
Prepaid and other assets	1,235	446
Accounts payable and other accrued liabilities	316	(729)
Accrued compensation	(1,793)	(1,260)
Deferred revenue	(992)	(3,542)
Net cash provided by (used in) operating activities	(4,868)	(11,515)
Investing Activities
Purchases of property and equipment	(461)	(134)
Acquisition of Businesses	(150)
Purchases of marketable securities	(18,295)	(24,614)
Maturities of marketable securities	16,220	26,297
Sales of marketable securities		25,666
Net cash provided by (used in) investing activities	(2,686)	27,215
Financing Activities
Proceeds from issuance of common stock	408	468
Net cash provided by (used in) financing activities	408	468
Net increase (decrease) in cash and cash equivalents	(7,146)	16,168
Cash and cash equivalents at beginning of period	29,076	24,043
Cash and cash equivalents at end of period	$ 21,930	$ 40,211