CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net (loss) income	$ (35,431)	$ 10,381	$ (69,725)
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	1,324	2,066	2,853
Gains on sales of fixed assets	(327)	0	0
Expenses for share-based compensation awards	6,536	6,362	9,515
Changes in assets and liabilities:
(Increase) decrease in accounts receivable	(5,421)	767	5,239
(Increase) decrease in other current assets	(754)	882	(333)
(Increase) decrease in deferred tax and other assets	(2,002)	1,050	617
(Decrease) increase in accounts payable and accrued expenses	(691)	(3,352)	3,847
Increase in deferred revenue - current	634	204	0
Increase (decrease) in deferred tax and other current liabilities	2,069	3	(58)
(Decrease) increase in deferred revenue - long term	(162)	162	0
(Decrease) increase in other liabilities	(419)	(138)	1,635
Net cash (used in) provided by operating activities	(34,644)	18,387	(46,410)
Cash flows from investing activities:
Capital expenditures	(767)	(226)	(2,171)
Proceeds from sales of fixed assets	390	0	0
Proceeds from redemption of auction rate securities	100	300	1,700
Net cash (used in) provided by investing activities	(277)	74	(471)
Cash flows from financing activities:
Proceeds from public offering of common stock, net of underwriting discounts and commissions and offering expenses	23,348	0	0
Proceeds from the exercise of stock options and sale of common stock under the employee stock purchase plans	306	3,726	3,896
Net cash provided by financing activities	23,654	3,726	3,896
Net (decrease) increase in cash and cash equivalents	(11,267)	22,187	(42,985)
Cash and cash equivalents at beginning of period	70,105	47,918	90,903
Cash and cash equivalents at end of period	$ 58,838	$ 70,105	$ 47,918