April 2013 Pillar Agreements - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended										9 Months Ended	1 Months Ended
	May 07, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Series D Preferred Stock [Member]	May 07, 2013 Series D Preferred Stock [Member]	Dec. 31, 2012 Series D Preferred Stock [Member]	Sep. 30, 2013 Series E Preferred Stock [Member]	May 07, 2013 Series E Preferred Stock [Member]	Sep. 30, 2013 Series D Preferred Stock [Member]	Sep. 30, 2013 Series E Preferred Stock [Member]	Dec. 31, 2012 Series E Preferred Stock [Member]	Sep. 30, 2013 Extinguishment Loss [Member]	Apr. 22, 2013 Pillar I Warrants [Member]	Apr. 30, 2013 Additional Pillar Warrants [Member]	Apr. 30, 2013 April 2013 Pillar Agreements [Member] Agreement	Apr. 30, 2013 April 2013 Pillar Agreements [Member] Series D Preferred Stock [Member]	Apr. 30, 2013 April 2013 Pillar Agreements [Member] Series E Preferred Stock [Member]
Effects of Agreements [Line Items]
Number of agreement															2
Unaffiliated ownership % that would trigger the right to require the Company to repurchase the Series D preferred stock																66.67%
Percentage of preferred stock holders who waived right to receive specified amount in liquidation																	100.00%
Number of Shares of Common Stock Callable By Pillar Warrants													1,000,000	1,000,000
Class of Warrant or Right Exercise Price Per Share of Warrants or Rights													0.61	0.79
Minimum closing price to redeem the warrants	2.80												2.80
Final exercise date of warrant														Jun. 01, 2014
Redemption price per share of warrants	0.01												0.01
Carrying value of preferred stock prior to extinguishment					$ 5,921,000			$ 3,701,000
Convertible Redeemable Preferred Stock			5,921,000			5,921,000
Carrying value of preferred stock				5,464,000			5,528,000		5,464,000	5,528,000	3,701,000
Fair value of the Pillar Warrants in equity at May 7, 2013		380,000
Extinguishment loss which was immediately charged to net loss applicable to common stockholders												1,750,000
Increase in stockholders equity resulting from preferred stock extinguishment and warrant issuance		$ 5,921,000
Expected volatility		3 years
Ownership percentage at which affiliates may not exercise warrants		19.99%