CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net loss	$ (34,021)	$ (35,107)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	774	1,063
Losses (gains) on sales of fixed assets	214	(307)
Expenses for share-based compensation awards	2,903	5,750
Changes in assets and liabilities:
Decrease in accounts receivable	6,240	387
Decrease (increase) in other current assets	1,041	(244)
(Decrease) increase in accounts payable and accrued expenses	(2,565)	155
(Decrease) in deferred revenue - current	(833)	0
(Decrease) in deferred revenue - long term	0	(153)
(Decrease) in other liabilities	(163)	(458)
Net cash used in operating activities	(26,410)	(28,914)
Cash flows from investing activities:
Cash acquired in acquisition of subsidiary	1,888	0
Capital expenditures	(77)	(759)
Proceeds from sales of fixed assets	153	368
Proceeds from redemption of auction rate securities	1,100	100
Net cash provided by (used in) investing activities	3,064	(291)
Cash flows from financing activities:
Equity issuance costs in connection with acquisition of subsidiary	(45)	0
Proceeds from public offering of common stock, net of underwriting discounts and commissions and offering expenses	40,079	0
Proceeds from the exercise of stock options	71	196
Net cash provided by financing activities	40,105	196
Net increase (decrease) in cash and cash equivalents	16,759	(29,009)
Cash and cash equivalents at beginning of period	58,838	70,105
Cash and cash equivalents at end of period	75,597	41,096
Supplemental disclosure of cash flow information:
Acquisition-related contingent consideration liability	15,900	0
Stock acquisition consideration	$ 11,265	$ 0