CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income (loss)	$ 10,381	$ (69,725)	$ (30,612)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	2,066	2,853	5,078
Write-off of fixed assets	0	0	334
Amortization of discounts, net of premiums, on marketable securities	0	0	889
Expenses for share-based compensation awards	6,362	9,515	12,986
Gain on sale of marketable securities	0	0	(237)
Changes in assets and liabilities:
Decrease (increase) in accounts receivable	767	5,239	(6,185)
Decrease (increase) in other current assets	882	(333)	2,063
Decrease (increase) in other assets	1,050	617	(1,667)
(Decrease) increase in accounts payable and accrued expenses	(3,352)	3,847	(660)
Increase (decrease) in deferred revenue - current	204	0	(31,645)
Increase (decrease) in other current liabilities	3	(58)	113
Increase in deferred revenue - long term	162	0	0
(Decrease) increase in other liabilities	(138)	1,635	(266)
Net cash provided by (used in) operating activities	18,387	(46,410)	(49,809)
Cash flows from investing activities:
Capital expenditures	(226)	(2,171)	(901)
Sales/maturities of marketable and auction rate securities	300	1,700	80,233
Decrease (increase) in restricted cash	0	0	320
Net cash provided by (used in) investing activities	74	(471)	79,652
Cash flows from financing activities:
Proceeds from the exercise of stock options and sale of common stock under the Employee Stock Purchase Plan	3,726	3,896	4,874
Net cash provided by financing activities	3,726	3,896	4,874
Net increase (decrease) in cash and cash equivalents	22,187	(42,985)	34,717
Cash and cash equivalents at beginning of period	47,918	90,903	56,186
Cash and cash equivalents at end of period	$ 70,105	$ 47,918	$ 90,903