CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities
Net income (loss)	$ 84,594	$ (22,667)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	1,910	1,650
Stock-based compensation	6,235	5,541
Forgiveness of notes receivable		1
Changes in operating assets and liabilities:
Receivables	160	268
Prepaid expenses and other current assets	(375)	73
Accounts payable	48	198
Accrued personnel-related expenses, accrued interest on convertible subordinated notes and other current liabilities	(6,657)	(6,031)
Deferred rent	(143)	776
Deferred revenue	(127,100)	(5,700)
Net cash used in operating activities	(41,328)	(25,891)
Cash flows from investing activities
Purchases of property and equipment	(1,103)	(1,381)
Purchases of marketable securities	(35,671)	(76,408)
Sales of marketable securities		5,000
Maturities of marketable securities	45,158	71,250
Payments received on notes receivable		300
Net cash provided by (used in) investing activities	8,384	(1,239)
Cash flows from financing activities
Payments on note payable and capital lease	(56)	(62)
Proceeds from issuances of common stock, net	2,532	11,733
Net cash provided by financing activities	2,476	11,671
Net decrease in cash and cash equivalents	(30,468)	(15,459)
Cash and cash equivalents at beginning of period	44,778	163,333
Cash and cash equivalents at end of period	$ 14,310	$ 147,874

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).