Fair Value of Assets and Liabilities - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Derivative warrant liability, Beginning balance		$ 0
Change in fair value of the derivative warrant liability	$ 29,966		$ 28,448
Derivative warrant liability, Ending balance		0
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Derivative warrant liability, Beginning balance		19,932
Change in fair value of the derivative warrant liability		28,448
Reclassification of derivative warrant liability		(48,380)
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Derivative warrant liability, Beginning balance		19,932
Change in fair value of the derivative warrant liability		28,448
Reclassification of derivative warrant liability		$ (48,380)