CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash Flows from Operating activities:
Net income (loss)	$ 121,271	$ (31,088)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	2,151	2,196
Share-based compensation expense	4,899	6,553
Amortization of premium on investments	708	586
Amortization of intangibles	150	149
Loss on disposal of assets		6
Changes in operating assets and liabilities:
Accounts receivable	(30,318)	(1,376)
Unbilled revenue	2,530	2,795
Prepaid expenses and other current assets	(855)	143
Accounts payable	(1,163)	(2,664)
Accrued expenses	(2,096)	(1,880)
Deferred rent	(23)	(35)
Deferred revenue	(1,066)	(1,345)
Other long term liabilities		25
Net cash provided by (used in) operating activities	96,188	(25,935)
Cash Flows from Investing activities:
Purchases of property and equipment	(4,242)	(624)
Purchases of marketable securities	(291,147)	(37,048)
Proceeds from maturities of marketable securities	120,182	61,101
Net cash (used in) provided by investing activities	(175,207)	23,429
Cash Flows from Financing activities:
Proceeds from issuance of common stock under stock plans	3,527	1,673
Payments on financed leasehold improvements	(258)	(362)
Principal payments on capital lease obligations	(1,079)	(1,100)
Net cash provided by financing activities	2,190	211
Decrease in cash and cash equivalents	(76,829)	(2,295)
Cash and cash equivalents, beginning of period	100,681	21,934
Cash and cash equivalents, end of period	23,852	19,639
Supplemental Cash Flow Information:
Cash paid for interest	$ 75	$ 192