Other Long Term Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Long Term Liabilities [Line Items]
Intangible contract liability	$ 5,030	$ 5,417
Accrued workers' compensation	31,868	28,769
Accrued deferred compensation	11,802	10,919
Lease financing obligation	7,508	7,634
ROU lease liability	$ 144,769	$ 51,247
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent
Deferred employer payroll taxes	$ 14,795
Other	696	$ 1,593
Other liabilities	$ 216,468	$ 105,579