Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities:
Net loss	$ (9,682)	$ (7,753)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	1,115	2,736
Provision for doubtful accounts and other adjustments to accounts receivable	419	193
Provision for excess and obsolete inventory	19	26
Excess tax benefits from stock-based compensation		(284)
Non-cash compensation related to stock options and restricted stock	1,178	2,107
Change in operating accounts:
Accounts receivable	(425)	4,809
Income tax receivable	352
Deferred taxes		(5,540)
Inventories	34	(8)
Prepaid expenses and other assets	357	(237)
Accounts payable and accrued liabilities	(1,477)	1,694
Net cash used in operating activities	(8,110)	(2,257)
Investing activities:
Capital expenditures	(55)	(6,561)
Proceeds from (purchase of) short-term investments	17,121	(1,985)
Net cash provided by (used in) investing activities	17,066	(8,546)
Financing activities:
Excess tax benefits from stock-based compensation		284
Cash received from stock sale for employee stock purchase plan	55	345
Cash received from exercise of stock options	10	7
Repurchase of common stock	(329)
Net cash provided by (used in) financing activities	(264)	636
Net increase (decrease) in cash and cash equivalents	8,692	(10,167)
Cash and cash equivalents, beginning of period	7,475	17,856
Cash and cash equivalents, end of period	16,167	7,689
Supplemental disclosures of cash flow information:
Cash paid for income taxes	$ 91	$ 224