Formation and Business of the Company (Details) - Common stock - Follow-On Offering $ / shares in Units, $ in Thousands	Sep. 23, 2015 USD ($) $ / shares shares
Formation and Business of the Company
Shares issued | shares	3,000,000
Public offering price (in dollars per share) | $ / shares	$ 22.00
Net proceeds after deducting underwriting discounts and commissions and offering expenses	$ 61,397
Payment of underwriting discounts and commissions and offering expenses	3,960
Offering expenses	$ 643