Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Salaries, wages, payroll taxes and benefits	$ 34,699	$ 21,138
Workers' compensation liability	81,653	67,775
Property, sales, use and other taxes	29,123	6,766
Insurance, other than workers' compensation	9,248	9,566
Accrued interest payable	9,408	6,740
Accrued merger and integration	25,206
Other	28,184	27,163
Accrued expenses	$ 217,521	$ 139,148