Assets And Liabilities Measured at Fair Value on Recurring Basis by Level Within Fair Value Hierarchy (Detail) (USD $)	Jun. 30, 2013		Dec. 31, 2012
Assets
Money Market Accounts	$ 200,000	[1]	$ 239,504	[1]
Targets	246,351	[2]	315,350	[2]
Convertible Debt Warrant Liability
Liabilities
Warrant Liability	1,064,416
MDFA Warrant Liability 1
Liabilities
Warrant Liability	13,350		111,811
MDFA Warrant Liability 2
Liabilities
Warrant Liability	16,079
Hercules Warrant Liability
Liabilities
Warrant Liability	851,620
Conversion Feature
Liabilities
Warrant Liability	1,064,828
Level 1
Assets
Money Market Accounts	200,000	[1]	239,504	[1]
Targets	246,351	[2]	315,350	[2]
Level 1 | Convertible Debt Warrant Liability
Liabilities
Warrant Liability	0
Level 1 | MDFA Warrant Liability 1
Liabilities
Warrant Liability	0		0
Level 1 | MDFA Warrant Liability 2
Liabilities
Warrant Liability	0
Level 1 | Hercules Warrant Liability
Liabilities
Warrant Liability	0
Level 1 | Conversion Feature
Liabilities
Warrant Liability	0
Level 2
Assets
Money Market Accounts	0	[1]	0	[1]
Targets	0	[2]	0	[2]
Level 2 | Convertible Debt Warrant Liability
Liabilities
Warrant Liability	0
Level 2 | MDFA Warrant Liability 1
Liabilities
Warrant Liability	0		0
Level 2 | MDFA Warrant Liability 2
Liabilities
Warrant Liability	0
Level 2 | Hercules Warrant Liability
Liabilities
Warrant Liability	0
Level 2 | Conversion Feature
Liabilities
Warrant Liability	0
Level 3
Assets
Money Market Accounts	0	[1]	0	[1]
Targets	0	[2]	0	[2]
Level 3 | Convertible Debt Warrant Liability
Liabilities
Warrant Liability	1,064,416
Level 3 | MDFA Warrant Liability 1
Liabilities
Warrant Liability	13,350		111,811
Level 3 | MDFA Warrant Liability 2
Liabilities
Warrant Liability	16,079
Level 3 | Hercules Warrant Liability
Liabilities
Warrant Liability	851,620
Level 3 | Conversion Feature
Liabilities
Warrant Liability	$ 1,064,828

[1] Included in cash and cash equivalents and restricted cash on the consolidated balance sheet

[2] Included in other current assets on the consolidated balance sheet.