Other Current Assets - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Other Current Assets	Sep. 30, 2013 $1.5 Million Purchase Agreement with Lincoln Park	Jan. 31, 2013 $1.5 Million Purchase Agreement with Lincoln Park	Sep. 30, 2013 $15 Million Purchase Agreement with Lincoln Park	Sep. 30, 2013 ATM Agreement Third Party	Sep. 30, 2013 Purchase Agreements Other Current Assets
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Deferred financing cost	$ 326,630	$ 341,166					$ 88,446	$ 238,184
Purchase agreement, aggregate shares opexa has right to sell	16,500,000			1,500,000	1,500,000	15,000,000
Legal costs, current			$ 44,070