CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Account Receivable, allowances aggregating	$ 18,106	$ 11,125
Closure and post-closure liabilities, current portion	5,884	8,791
Remedial liabilities, current portion	$ 23,587	$ 19,545
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	80,000,000	80,000,000
Common stock, issued shares	60,672,180	60,385,453
Common stock, outstanding shares	60,672,180	60,385,453