Organization and Description of Business (Details) - USD ($)
$ / shares in Units, $ in Thousands, shares in Millions
12 Months Ended
Mar. 19, 2014
Mar. 19, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Class of Stock [Line Items]          
Stock Issued During Period, Value, New Issues       $ 185,628  
Proceeds from Issuance Initial Public Offering     $ 0 $ 189,943 $ 0
IPO [Member]          
Class of Stock [Line Items]          
Stock Issued During Period, Value, New Issues   $ 204,200      
Proceeds from Issuance Initial Public Offering   185,600      
Payments of Stock Issuance Costs, Underwriter Fees and Commissions   14,300      
Deferred Offering Costs $ 4,300 $ 4,300      
IPO [Member] | Class B [Member]          
Class of Stock [Line Items]          
Stock Issued During Period, Shares, New Issues 12.8 12.8      
Shares Issued, Price Per Share $ 16 $ 16