CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Receivables, allowance for doubtful accounts	$ 5,028	$ 6,250
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	95,000,000	95,000,000
Common stock, issued	49,987,000	49,658,000
Common stock, outstanding	44,692,000	44,380,000
Treasury stock, shares	5,295,000	5,278,000
Senior Notes
Deferred financing costs	$ 3,671	$ 4,150