Condsolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Account Receivable, allowances aggregating	$ 11,125	$ 12,683
Closure and post-closure liabilities, current portion	8,791	3,885
Remedial liabilities, current portion	$ 15,330	$ 11,174
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized shares	80,000,000	80,000,000
Common stock, issued shares	60,385,453	53,182,859
Common stock, outstanding shares	60,385,453	53,182,859