CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable	$ 9,197	$ 7,919
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	64,690,526	64,603,344
Common stock, shares outstanding	49,092,583	48,822,013
Non-vesting restricted shares	1,050,462	993,934
Treasury Stock, Shares	15,597,943	15,781,331