Capital Stock - Additional Information (Detail) (USD $)	3 Months Ended				3 Months Ended			3 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Jun. 29, 2012	Mar. 31, 2013 Employee Stock Purchase Plan [Member]	Mar. 31, 2013 Warrant 2 [Member]	Mar. 31, 2013 Warrant 3 [Member]	Mar. 31, 2013 Pyxis Innovations Inc [Member]	Mar. 31, 2013 Series A-1 Preferred Stock [Member]	Jun. 29, 2012 Series A-1 Preferred Stock [Member]	Jun. 29, 2012 Series B Preferred Stock [Member]	Mar. 31, 2013 Series B Preferred Stock [Member]
Stockholders Equity [Line Items]
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	6,000,000	6,000,000
Convertible preferred stock, shares issued	5,500,000	5,500,000						5,000,000	5,000,000	500,000	500,000
Convertible preferred stock, shares outstanding	5,500,000	5,500,000						5,000,000			500,000
Common stock, shares authorized	150,000,000	150,000,000									150,000,000
Common stock, par value	$ 0.001	$ 0.001									$ 0.001
Common stock, outstanding or reserved for issuance											85,590,685
Common stock, shares outstanding	36,782,208	36,761,864									36,782,208
Shares reserved for conversion of Preferred to common stock								28,160,200			39,089,161
Shares reserved for conversion of debt							2,521,222
Debt outstanding	$ 14,316,255
Shares reserved for potential exercise	4,279,280
Shares reserved for exercise of outstanding warrants			437,158		1,750,000	437,158
Warrants exercise price per share			0.2745		1.30	0.2745
Expiration date of warrants					Mar. 05, 2015	Jun. 29, 2017
Proceeds from private placement of preferred stock										3,000,000
Convertible preferred stock current conversion price								$ 0.3196			$ 0.2745
Net Proceeds from issuance of Series B Convertible preferred Stock										2,700,000
Warrants issued in connection with private placement of preferred stock	104,907
Accrued dividend rate	8.00%
Convertible preferred stock, liquidation preference	$ 24,000,000							$ 18,000,000			$ 6,000,000
Convertible preferred stock, effective purchase price								$ 1.80			$ 6.00
Shares Reserved For Exercise Of Rights				731,656
Conversion of Stock, Shares Converted											10,928,961