Schedule Of Accounts Payable And Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accounts Payable and Accrued Liabilities [Line Items]
Trade accounts payable	$ 46,662	$ 45,447
Accrued salaries and wages	42,443	49,802
Accrued workers' compensation and auto liability	8,455	8,092
Accrued litigation	8,795	11,221
Accrued employee medical insurance	10,480	10,353
Accrued property taxes	24,434	23,405
Accrued interest	3,509	14,270
Other	21,222	33,136
Accounts payable and accrued expenses, total	$ 166,000	$ 195,726