Prepaid Expenses and Other Current Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid expenses and other current assets	$ 1,706	$ 2,140
Prepaid insurance	399	34
Research and development clinical costs	1,298	262
Other costs	9	11
IPO costs		$ 1,833