Summary of Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Accrued Liabilities [Line Items]
Salaries, wages, payroll taxes and benefits	$ 45,836	$ 55,430
Workers' compensation liability	74,975	68,441
Property, sales, use and other taxes	12,367	9,749
Insurance, other than workers' compensation	10,129	10,419
Accrued interest payable	7,604	7,664
Deferred revenue - current		1,523
Other	9,546	5,406
Accrued expenses	$ 160,457	$ 158,632