Stockholders' Equity - Summary of Stock Option Activity under Equity Incentive Plan and Warrants Issued Outside Plan (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options or Warrants, Balance outstanding, Beginning Balance	144,000	177,750
Number of Options or Warrants, Granted	1,812,906	0
Number of Options or Warrants, Exercised	0	0
Number of Options or Warrants, Cancelled (unvested)	(42,000)	(2,844)
Number of Options or Warrants, Expired (vested)		(30,906)
Number of Options or Warrants, Balance outstanding, Ending Balance	1,914,906	144,000	177,750
Weighted Average Exercise Price, Balance outstanding, Beginning Balance	$ 31.74	$ 33.40
Number of Options or Warrants, Exercisable, Ending Balance	1,912,906
Weighted Average Exercise Price, Granted	$ 0.80	$ 0.80
Weighted Average Exercise Price, Exercised	$ 0	$ 0
Weighted Average Exercise Price, Cancelled (unvested)	$ 32.02	$ 14.80
Weighted Average Exercise Price, Expired (vested)		$ 41.70
Weighted Average Exercise Price, Balance outstanding, Ending Balance	$ 2.44	$ 31.74	$ 33.40
Weighted Average Exercise Price, Exercisable, Ending Balance	$ 2.44
Weighted Average Remaining Contractual Life (in years), Granted	9 years 1 month 6 days
Weighted Average Remaining Contractual Life (in years), Balance	8 years 8 months 27 days	2 years 1 month 6 days	2 years 9 months 18 days
Weighted Average Remaining Contractual Life (in years), Exercisable, Ending Balance	8 years 8 months 27 days