Warrants (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Aug. 16, 2017
Class of Warrant or Right [Line Items]
Common stock warrants	599,670	2,575,000
Proceeds from warrants exercised	$ 3,334,176
Common Stock
Class of Warrant or Right [Line Items]
Beginning Balance	55,049
Granted	14,852,994
Exercised	(599,670)
Cancelled	(36)
Ending Balance	14,308,337
Beginning Balance	$ 238.90
Granted	3.15
Exercised	5.56
Cancelled	238.90
Ending Balance	$ 3.51