CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net loss	$ (47,485,437)	$ (17,963,873)	$ (14,424,545)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	120,399	113,936	95,517
Loss on retirement of equipment and furnishings	2,595	42,267	10,206
Gain (loss) on warrant liability	20,210,094	(2,766,704)	(7,915,027)
Foreign exchange (gain) loss	(118,438)	0	17,834
Stock-based compensation expense	3,985,106	2,391,529	1,436,840
Changes in assets and liabilities:
Receivable	(835)	65,902	83,302
Interest receivable	18,053	14,758	76,349
Income taxes recoverable	0	0	519,158
Prepaid expenses and other current assets	(1,132,428)	(173,245)	277,232
Accounts payable	789,655	984,547	1,046,539
Accrued expenses and other current liabilities	(139,747)	(1,753,767)	2,105,212
Total adjustments	23,734,454	(1,080,777)	(2,246,838)
Net cash used in operating activities	(23,750,983)	(19,044,650)	(16,671,383)
Cash flows from investing activities:
Proceeds from matured marketable securities	24,000,000	23,125,442	25,644,481
Purchase of short-term investments	(27,084,980)	(29,067,770)	(23,134,292)
Proceeds from sale of affiliate's shares	0	0	6,938,603
Purchases of equipment and furnishings	(41,809)	(141,639)	(52,868)
Net cash provided by (used in) investing activities	(3,126,789)	(6,083,967)	9,395,924
Cash flows from financing activities:
Proceeds from common stock issued in public offering, net of fees	24,094,530	21,476,815	18,939,619
Proceeds from issuance of restricted stock to employee	0	100	0
Repurchase of Company's own stock for treasury	(117,070)	0	0
Net proceeds from exercise of stock options and warrants	39,336	7,200	0
Net cash provided by financing activities	24,016,796	21,484,115	18,939,619
Net increase (decrease) in cash and cash equivalents	(2,860,976)	(3,644,502)	11,664,160
Cash and cash equivalents at beginning of year	14,344,088	17,988,590	6,324,430
Cash and cash equivalents at end of year	11,483,112	14,344,088	17,988,590
Supplemental disclosures of non-cash financing activities:
Warrants issued in connection with financing	0	0	12,216,680
Repurchase of Company's own stock for treasury	27,829	0	0
Equipment and furnishings purchased but not paid	3,360	1,506	0
Supplemental disclosure of Cash Flow Information:
Cash paid during the year for income taxes	$ 25,750	$ 0	$ 0