Components of Deferred Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Self-insurance reserves	$ 64,181	$ 85,940
Compensation accruals	63,021	83,328
Doubtful accounts and other reserves	20,809	38,017
Other currently non-deductible accrued liabilities	19,759	24,058
State and foreign net operating loss carryforwards and other state and foreign deferred tax assets	76,439	66,639
Net pension liabilities – OCI only	2,825	5,926
Other combined items – OCI only		815
Deferred income tax assets, Gross	247,034	304,723
Valuation Allowance	(70,227)	(56,333)
Total deferred income taxes	176,807	248,390
Depreciable and amortizable assets	226,389	332,326
Other combined items – OCI only	550
Other liabilities	1,824	2,949
Deferred income tax liabilities, Gross	$ 228,763	$ 335,275