Annual report pursuant to Section 13 and 15(d)

Stockholder's Equity - Common Stock (Details)

v3.8.0.1
Stockholder's Equity - Common Stock (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2017
Dec. 31, 2015
Class of Stock [Line Items]      
Repurchase of common stock $ 2,041,851    
Shares of common stock offered (in shares) 11,886,216 11,915,830  
Common Stock [Member]      
Class of Stock [Line Items]      
Authorized amount of shares to be repurchased     $ 10,000,000
Repurchase of common stock (in shares) 90,613    
Repurchase of common stock $ 91