Prepaids and Other Current Assets - Summary of Prepaids and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Prepaid Expense And Other Assets Current [Abstract]
Offering costs	$ 6,300	$ 4,397
Prepaid insurance	469	249
Other	388	251
Total prepaids and other current assets	$ 857	$ 4,897