Fair Value Measurements (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	$ 0	$ 4,145
Common stock warrants [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0	4,145
Fair Value, Inputs, Level 1 [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0	0
Fair Value, Inputs, Level 1 [Member] | Common stock warrants [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0	0
Fair Value, Inputs, Level 2 [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0	0
Fair Value, Inputs, Level 2 [Member] | Common stock warrants [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0	0
Fair Value, Inputs, Level 3 [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0	4,145
Fair Value, Inputs, Level 3 [Member] | Common stock warrants [Member]
Liabilities Measured on Recurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	$ 0	$ 4,145