CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
CONSOLIDATED BALANCE SHEETS
Receivables allowance (in dollars)	$ 1,501	$ 1,416
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	61,728,605	61,531,025
Treasury stock, shares	10,804,009	10,781,001