Consolidated Statements of Changes in Stockholders Equity - USD ($)	Direct and ATM [Member] Common Stock [Member]	Direct and ATM [Member] Additional Paid-in Capital [Member]	Direct and ATM [Member] Treasury Stock [Member]	Direct and ATM [Member] AOCI Attributable to Parent [Member]	Direct and ATM [Member] Retained Earnings [Member]	Direct and ATM [Member]	Direct [Member] Common Stock [Member]	Direct [Member] Additional Paid-in Capital [Member]	Direct [Member] Treasury Stock [Member]	Direct [Member] AOCI Attributable to Parent [Member]	Direct [Member] Retained Earnings [Member]	Direct [Member]	Common Stock Warrants [Member] Common Stock [Member]	Common Stock Warrants [Member] Additional Paid-in Capital [Member]	Common Stock Warrants [Member] Treasury Stock [Member]	Common Stock Warrants [Member] AOCI Attributable to Parent [Member]	Common Stock Warrants [Member] Retained Earnings [Member]	Common Stock Warrants [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2014																			19,984,203		113,400
Balance at Dec. 31, 2014																			$ 200,976	$ 229,778,703	$ (2,064,609)	$ (16,032)	$ (195,073,702)	$ 32,825,336
Net loss																							(22,461,084)	(22,461,084)
Registered Direct and ATM common stock offerings (in shares)	3,283,608																		14,000
Registered Direct and ATM common stock offerings	$ 32,836	$ 7,703,607				$ 7,736,443
Expiration of reset provision of the common stock warrants issued in connection with the November 2013 Hercules Loan																				336,254				336,254
Unrealized gain on investment securities																						12,174		12,174
Stock-based compensation expense																				1,828,896				1,828,896
Issuance of restricted stock																			$ 140	20,775				20,915
Issuance of common stock out of treasury (in shares)																			37,476		(37,476)
Issuance of common stock out of treasury																					$ 682,304		(595,574)	86,730
Balance (in shares) at Dec. 31, 2015																			23,319,287		75,924
Balance at Dec. 31, 2015																			$ 233,952	239,668,235	$ (1,382,305)	(3,858)	(218,130,360)	20,385,664
Realized and unrealized gains and losses, net, on investments securities																								12,174
Net loss																							(22,053,726)	(22,053,726)
Registered Direct and ATM common stock offerings (in shares)							7,454,607												126,518
Registered Direct and ATM common stock offerings							$ 74,546	$ 6,700,470				$ 6,775,016
Stock-based compensation expense																				1,332,838				1,332,838
Issuance of restricted stock																			$ 1,265	176,920				178,185
Issuance of common stock out of treasury (in shares)																			71,245		(71,245)
Issuance of common stock out of treasury																					$ 1,297,117		(1,195,626)	101,491
Balance (in shares) at Dec. 31, 2016																			31,221,657		4,679
Balance at Dec. 31, 2016																			$ 312,263	247,878,463	$ (85,188)		(241,379,712)	6,725,826
Conversion of common stock warrants (in shares)													250,000
Conversion of common stock warrants													$ 2,500					$ 2,500
Realized and unrealized gains and losses, net, on investments securities																						$ 3,858		$ 3,858