CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net (loss)	$ (27,608)	$ (26,924)	$ (17,263)
Adjustments to reconcile net (loss) to net cash used in operating activities:
Depreciation and amortization	36	71	68
Stock-based compensation	7,563	6,162	4,367
Net change in deferred taxes	0	3,158	5,663
Change in value of derivative liability	(1,608)	927	5,595
Changes in assets and liabilities:
Prepaid expenses and other current assets	(243)	(23)	(3)
Prepaid taxes	14,963	(4,934)	(10,459)
Deferred revenue	667	0	0
Accounts payable and accrued liabilities	(1,449)	1,970	708
Income tax liability	395	0	(6,928)
Net cash used in operating activities	(7,284)	(19,593)	(18,252)
Cash flows from investing activities:
Purchase of property and equipment	(7)	(37)	(51)
Purchase of investments	(92,729)	(59,342)	(34,082)
Proceeds from sale or maturity of investments	99,362	47,299	63,101
Net cash provided by (used in) investing activities	6,626	(12,080)	28,968
Cash flows from financing activities:
Proceeds from exercise of options	170	1,691	1,068
Proceeds from exercise of warrants	0	161	3,063
Net cash provided by financing activities	170	1,852	4,131
Net increase (decrease) in cash and cash equivalents	(488)	(29,821)	14,847
Cash and cash equivalents, beginning of year	19,661	49,482	34,635
Cash and cash equivalents, end of year	19,173	19,661	49,482
Supplemental disclosure of cash flow information:
Cash paid during the year for taxes	0	0	9,600
Cash paid during the year for interest	$ 0	$ 0	$ 0