Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accounting Policies [Abstract]
Cash equivalents, highly-liquid investments maturity	3 months
Property, Plant and Equipment [Line Items]
Impairment losses	$ 0
Expected dividend yield	0.00%
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Early Exercise of Stock Options [Member]
Class of Stock [Line Items]
Shares issued upon early exercise of stock options and are subject to future vesting		19,265