Consolidated Statement of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2011	$ 10,725,124us-gaap_StockholdersEquity	$ 224,280	$ 343,060,153	$ (332,600,022)	$ 40,713
Beginning Balance, Shares at Dec. 31, 2011		22,427,955
Net loss	(28,491,153)us-gaap_NetIncomeLoss			(28,491,153)
Unrealized gain on foreign currency translation	151,125				151,125
Change in unrealized loss on securities available-for-sale	1,339				1,339
Issuance of common stock and warrants, net of issuance cost of $900,992, $2,051,699 and $1,335,327 in 2012, 2013 and 2014 respectively	28,725,507	145,460	28,580,047
Issuance of common stock and warrants, net of issuance cost of $900,992, $2,051,699 and $1,335,327 in 2012, 2013 and 2014 respectively, Shares		14,546,042
Common stock issued for external services	175,235	1,021	174,214
Common stock issued for external services, shares		102,058
Common stock issued pursuant to employee benefit plan	97,017	1,299	95,718
Common stock issued pursuant to employee benefit plan, shares		129,893
Compensation expense from grant of options, restricted stock units and stock (fair value)	2,655,884	1,825	2,654,059
Compensation expense from grant of options, restricted stock units and stock (fair value), shares		182,502
Exercise of director stock options	3,629	36	3,593
Exercise of director stock options, shares	3,629	3,629
Exercise and net settlement of restricted stock units	(59,090)	1,142	(60,232)
Exercise and net settlement of restricted stock units, shares		114,226
Ending Balance at Dec. 31, 2012	13,984,617us-gaap_StockholdersEquity	375,063	374,507,552	(361,091,175)	193,177
Ending Balance, Shares at Dec. 31, 2012		37,506,305
Net loss	(26,439,159)us-gaap_NetIncomeLoss			(26,439,159)
Unrealized gain on foreign currency translation	57,568				57,568
Change in unrealized loss on securities available-for-sale	1,356				1,356
Issuance of common stock and warrants, net of issuance cost of $900,992, $2,051,699 and $1,335,327 in 2012, 2013 and 2014 respectively	24,879,573	169,385	24,710,188
Issuance of common stock and warrants, net of issuance cost of $900,992, $2,051,699 and $1,335,327 in 2012, 2013 and 2014 respectively, Shares		16,938,575
Common stock issued for external services	154,111	1,049	153,062
Common stock issued for external services, shares		104,911
Common stock issued pursuant to employee benefit plan	132,071	829	131,242
Common stock issued pursuant to employee benefit plan, shares		82,863
Compensation expense from grant of options, restricted stock units and stock (fair value)	2,322,489		2,322,489
Exercise of director stock options	3,452	35	3,417
Exercise of director stock options, shares	3,452	3,452
Exercise and net settlement of restricted stock units	(342,366)	3,627	(345,993)
Exercise and net settlement of restricted stock units, shares		362,657
Common stock issued as consideration in the acquisition of a patent portfolio	200,000	1,395	198,605
Common stock issued as consideration in the acquisition of a patent portfolio, shares		139,548
Ending Balance at Dec. 31, 2013	14,953,712us-gaap_StockholdersEquity	551,383	401,680,562	(387,530,334)	252,101
Ending Balance, Shares at Dec. 31, 2013		55,138,311
Net loss	(32,741,274)us-gaap_NetIncomeLoss			(32,741,274)
Unrealized gain on foreign currency translation	(186,711)				(186,711)
Issuance of common stock and warrants, net of issuance cost of $900,992, $2,051,699 and $1,335,327 in 2012, 2013 and 2014 respectively	22,359,386	128,522	22,230,864
Issuance of common stock and warrants, net of issuance cost of $900,992, $2,051,699 and $1,335,327 in 2012, 2013 and 2014 respectively, Shares		12,852,221
Common stock issued for external services	154,708	1,202	153,506
Common stock issued for external services, shares		120,149
Common stock issued pursuant to employee benefit plan	183,677	1,157	182,520
Common stock issued pursuant to employee benefit plan, shares		115,722
Compensation expense from grant of options, restricted stock units and stock (fair value)	1,646,608		1,646,608
Exercise of director stock options, shares	0
Exercise and net settlement of restricted stock units	(499,333)	5,034	(504,367)
Exercise and net settlement of restricted stock units, shares		503,371
Ending Balance at Dec. 31, 2014	$ 5,870,773us-gaap_StockholdersEquity	$ 687,298	$ 425,389,693	$ (420,271,608)	$ 65,390
Ending Balance, Shares at Dec. 31, 2014		68,729,774

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