CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2013	$ 7,335,712	$ 5,230	$ 217,877,117	$ (218,710)	$ (210,327,925)
Balance (in shares) at Dec. 31, 2013		52,304,246
Net income (loss)	(9,955,395)	$ 0	0	0	(9,955,395)
Unrealized losses on available-for-sale securities	0
Foreign currency translation adjustments	(10,818)	0	0	(10,818)	0
Realization of cumulative translation adjustment	0
Issuance of common stock, net issuance costs	17,686,095	$ 1,052	17,685,043	0	0
Issuance of common stock, net issuance costs (in shares)		10,520,454
Share-based compensation - stock options	1,649,994	$ 0	1,649,994	0	0
Shares issued upon exercise of stock options	455,840	$ 35	455,805	0	0
Shares issued upon exercise of stock options (in shares)		352,718
Shares issued upon exercise of warrants	1,107,064	$ 42	1,107,022	0	0
Shares issued upon exercise of warrants (in shares)		419,218
Employee vesting of restricted shares	5,653	$ 1	5,652	0	0
Employee vesting of restricted shares (in shares)		6,667
Balance at Dec. 31, 2014	18,274,145	$ 6,360	238,780,633	(229,528)	(220,283,320)
Balance (in shares) at Dec. 31, 2014		63,603,303
Net income (loss)	(3,440,705)	$ 0	0	0	(3,440,705)
Unrealized losses on available-for-sale securities	0
Foreign currency translation adjustments	336	0	0	336	0
Realization of cumulative translation adjustment	229,192	0	0	229,192	0
Share-based compensation - stock options	613,017	0	613,017	0	0
Shares issued upon exercise of stock options	973,132	$ 78	973,054	0	0
Shares issued upon exercise of stock options (in shares)		778,783
Balance at Dec. 31, 2015	16,649,117	$ 6,438	240,366,704	0	(223,724,025)
Balance (in shares) at Dec. 31, 2015		64,382,086
Net income (loss)	193,854,173	$ 0	0	0	193,854,173
Unrealized losses on available-for-sale securities	(1,052)	0	0	(1,052)	0
Dividends declared	(197,083,993)	0	(197,083,993)	0	0
Foreign currency translation adjustments	0
Realization of cumulative translation adjustment	0
Share-based compensation - stock options	2,240,015	0	2,240,015	0	0
Shares issued upon exercise of stock options	3,801,720	$ 250	3,801,470	0	0
Shares issued upon exercise of stock options (in shares)		2,492,639
Employee vesting of restricted shares	(889)	$ 85	(974)	0	0
Employee vesting of restricted shares (in shares)		851,733
Balance at Dec. 31, 2016	$ 19,459,091	$ 6,773	$ 49,323,222	$ (1,052)	$ (29,869,852)
Balance (in shares) at Dec. 31, 2016		67,726,458