Related Party Transactions (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Aug. 06, 2013	Mar. 26, 2013		Sep. 19, 2012	Apr. 18, 2012	Sep. 14, 2011	Mar. 30, 2011		Dec. 31, 2012 Marxe And Greenhouse [Member]	Sep. 19, 2012 Marxe And Greenhouse [Member]	Apr. 18, 2012 Marxe And Greenhouse [Member]	Dec. 31, 2012 Wellington [Member]	Sep. 14, 2011 Wellington [Member]	Mar. 30, 2011 Wellington [Member]	Nov. 19, 2010 Wellington [Member]
Related Party Transaction [Line Items]
Amount paid for patent-related legal services	$ 587,000	$ 906,000	$ 784,000
Percentage of ownership of outstanding stock												5.00%			5.00%
Sale of common stock, number of shares	93,208,471	82,903,609		3,681,000	4,715,000	[1]	4,382,000	8,139,000	7,800,000	3,332,117	[2]		300,000	2,857,143		500,000	1,200,000	2,829,520
Sale of stock price per share				$ 3.80	$ 3.25	[1]	$ 2.30	$ 1.05	$ 0.88	$ 0.71	[2]		$ 2.30	$ 1.05		$ 0.88	$ 0.71	$ 0.42

[1] Ladenburg Thalmann Financial Services Inc. acted as underwriter for the transaction.

[2] Offering included the sale of 3,332,117 shares of common stock at $0.71 per share and 2,691,360 units, each consisting of one share of common stock and three-tenths of a warrant to purchase common stock, at $0.81 per unit. The warrants are exercisable beginning September 30, 2011 and expire on September 30, 2016. The warrants were recorded at their relative fair value of approximately $0.4 million as estimated at their grant date using the Black-Scholes option pricing model (see Note 8)