Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Statement of Financial Position [Abstract]    
Accounts receivable, allowance for doubtful accounts $ 29,872 $ 18,322
Preferred stock, par value (USD per share) $ 0.01 $ 0.01
Preferred stock, shares authorized (shares) 20,000,000 20,000,000
Preferred stock, shares issued (shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Common stock, par value (USD per share) $ 0.01 $ 0.01
Common stock, shares authorized (shares) 300,000,000 300,000,000
Common stock, shares issued (in shares) 48,488,616 48,156,990
Common stock, shares outstanding (in shares) 48,488,616 48,156,990