Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Subsidiary Sale Of Stock [Line Items]
Payment of offering costs		$ 1,873,000
IPO [Member]
Subsidiary Sale Of Stock [Line Items]
Deferred offering costs		1,000,000
Payment of offering costs	$ 1,900,000
General and Administrative Expense [Member]
Subsidiary Sale Of Stock [Line Items]
Aggregate foreign exchange gain (loss)	$ (9,000)	$ 14,000