Stock-Based Compensation Expense (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Outstanding at December 31, 2012 - Shares	3,005,532	2,726,137
Granted - Shares	9,985,000
Exercised - Shares	0
Expired - Shares	(140,391)
Outstanding at June 30, 2013 - Shares	12,850,141	2,726,137
Exercisable at June 30, 2013 - Shares	3,624,233
Vested and expected to vest as of June 30, 2013 - Shares	9,027,638
Outstanding - Weighted average exercise price (in dollars per share)	$ 0.76
Granted - Weighted average exercise price (in dollars per share)	$ 0.12
Exercised - Weighted average exercise price (in dollars per share)	$ 0
Expired - Weighted average exercise price (in dollars per share)	$ (0.58)
Outstanding - Weighted average exercise price (in dollars per share)	$ 0.26
Exercisable - Weighted average exercise price (in dollars per share)	$ 0.42