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Nature of Operations (Details) - USD ($)
12 Months Ended
Oct. 06, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Completion of IPO [Abstract]        
Sales price per share (in dollars per share) $ 11.00      
Gross proceeds from issuance of common stock $ 92,500,000 $ 0 $ 86,059,087 $ 0
Net proceeds from issuance of common stock 82,800,000      
Underwriting discounts, commissions and other offering costs $ 9,700,000      
Common shares issued upon conversion of preferred stock (in shares) 18,566,856      
Preferred stock, shares outstanding (in shares)   0 0  
IPO [Member]        
Completion of IPO [Abstract]        
Shares of common stock sold (in shares) 8,412,423      
Over-Allotment Option [Member]        
Completion of IPO [Abstract]        
Shares of common stock sold (in shares) 1,097,272