Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Statement of Financial Position [Abstract]    
Accumulated amortization of debt financing costs $ 11,360 $ 9,350
Class A common stock, par value (in dollars per share) $ 0.01 $ 0.01
Class A common stock, shares authorized 500,000,000 500,000,000
Class A common stock, shares outstanding 88,569,377 87,410,687
Treasury stock, shares 115,146 110,964