Other Current Assets - Additional Information (Detail) (USD $)									1 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Other Current Assets	Jun. 30, 2013 $1.5 Million Purchase Agreement with Lincoln Park	Jan. 31, 2013 $1.5 Million Purchase Agreement with Lincoln Park	Jun. 30, 2013 $15 Million Purchase Agreement with Lincoln Park	Jun. 30, 2013 ATM Agreement Third Party	Jun. 30, 2013 Purchase Agreement Other Current Assets	Aug. 13, 2013 Common Stock Offering Subsequent Event	Jun. 30, 2013 Common Stock Offering Other Current Assets
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Differed financing cost	$ 440,305	$ 341,166					$ 88,446	$ 238,154		$ 113,705
Purchase agreement, aggregate shares opexa has right to sell	16,500,000			1,500,000	1,500,000	15,000,000
Common stock issued									12,000,000
Advance payments to vendors and consultants	162,028
Legal costs, current			$ 44,070