CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance for losses	$ 4,491	$ 3,396
Preferred stock, par value (in USD per share)	$ 10.00	$ 10.00
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	48,147,969	48,147,969
Common stock, shares outstanding	48,147,969	48,147,969
Treasury stock, shares	10,596,386	11,381,733