Condensed Consolidated Balance Sheets Balance Sheet Parenthetical - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Allowance for doubtful accounts $ 890 $ 1,065
Preferred Stock, Par Value (in usd per share) $ 0.0001 $ 0.0001
Preferred Stock, Shares Authorized 10,000,000 10,000,000
Preferred Stock, Shares Issued 0 0
Class B common stock    
Common Stock, Par Value (in usd per share) $ 0.0001 $ 0.0001
Common Stock, Shares Authorized 75,000,000 75,000,000
Common Stock, Shares Issued 16,372,489 18,336,609
Common Stock, Shares Outstanding 16,372,489 18,336,609
Class A common stock    
Common Stock, Par Value (in usd per share) $ 0.0001 $ 0.0001
Common Stock, Shares Authorized 750,000,000 750,000,000
Common Stock, Shares Issued 62,703,400 58,381,813
Common Stock, Shares Outstanding 62,703,400 58,381,813