Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities
Net loss	$ (74,082)	$ (98,337)
Adjustments to reconcile net loss to net cash used in operating activities
Non-cash interest expense	6,393	2,341
Depreciation and amortization	2,811	1,926
Stock-based compensation	9,941	7,953
Other non-cash items		810
Changes in operating assets and liabilities
Purchased premiums and interest on available-for-sale securities	432	(1,535)
Accounts receivable	4,130	432
Accounts payable, accrued expenses and other	(2,077)	19,741
Deferred revenues	49,526	(4,738)
Other assets and liabilities, net	(197)	3,657
Net cash used in operating activities	(3,123)	(67,750)
Cash flows from investing activities
Purchases of available-for-sale securities	(70,934)	(78,699)
Proceeds from maturities of available-for-sale securities	106,733	74,140
Purchases of property and equipment	(4,714)	(9,061)
Other investing activities, net		(56)
Net cash provided by (used in) investing activities	31,085	(13,676)
Cash flows from financing activities
Proceeds from exercise of common stock options and warrants	6,581	28,271
Proceeds from convertible notes issued by majority owned subsidiary, net of issuance costs	700	274
Proceeds from issuance of convertible senior notes, net of issuance costs		120,621
Payments of dividends on Series B convertible preferred stock	(7)	(3)
Other financing activities, net	1
Net cash provided by financing activities	7,275	149,163
Net increase in cash and cash equivalents	35,237	67,737
Cash and cash equivalents, beginning of period	65,086	37,714
Cash and cash equivalents, end of period	100,323	105,451
Non-cash investing and financing activities
Issuance of derivative liability	88	35
Property and equipment in accounts payable and accrued expenses	653	1,761
Disposal of fully depreciated assets	1,598	136
Receivables related to stock option exercises	841
Reclassification of deferred financing costs to issuance costs		278
Value of equity premium on convertible senior notes, net of issuance costs, classified in Stockholders' Deficit		51,876
Supplemental disclosure of cash flows
Cash paid for interest	$ 8,806	$ 2,849