Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Consolidated net loss	$ (100,294)	$ (104,126)	$ (110,211)
Adjustments to reconcile consolidated net loss to net cash used in operating activities:
Depreciation and amortization	1,928	2,863	4,190
Impairment of assets	13,544	0	0
Increase (decrease) in fair value of Symphony Icon, Inc. purchase liability	1,428	(2,210)	9,887
Stock-based compensation	7,081	7,421	6,495
Gain on disposal of property and equipment	(1,631)	0	0
Amortization of debt issuance costs	100	0	0
Deferred tax benefit	(70)	0	0
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	457	588	(1,028)
(Increase) decrease in prepaid expenses and other current assets	(128)	1,713	(2,601)
(Increase) decrease in other assets	0	(9)	96
Increase (decrease) in accounts payable and other liabilities	1,266	3,119	(995)
Increase (decrease) in deferred revenue	697	(438)	(293)
Net cash used in operating activities	(75,622)	(91,079)	(94,460)
Cash flows from investing activities:
Purchases of property and equipment	(80)	(1,721)	(492)
Proceeds from disposal of property and equipment	2,170	130	85
Purchases of investments	(221,953)	(111,490)	(233,250)
Maturities of investments	111,444	212,625	135,850
Net cash provided by (used in) investing activities	(108,419)	99,544	(97,807)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of fees	202,270	1,084	38,109
Repurchase of common stock	(887)	(873)	(285)
Proceeds from debt borrowings, net of fees	84,135	0	0
Repayment of debt borrowings	(1,710)	(1,574)	(1,443)
Other financing activities	0	(26)	0
Net cash provided by (used in) financing activities	283,808	(1,389)	36,381
Net increase (decrease) in cash and cash equivalents	99,767	7,076	(155,886)
Cash and cash equivalents at beginning of year	37,499	30,423	186,309
Cash and cash equivalents at end of year	137,266	37,499	30,423
Supplemental disclosure of cash flow information:
Cash paid for interest	1,761	1,897	2,028
Supplemental disclosure of noncash investing and financing activities:
Unrealized gain (loss) on investments	(65)	(21)	2
Common stock issued in satisfaction of Symphony Icon base payment obligation	$ 5,750	$ 0	$ 35,000