Income Taxes - Significant Components of Federal and State Deferred Tax Assets And Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for doubtful accounts	$ 14,599	$ 3,109
Deferred compensation	7,350	6,601
Accrued insurance claims	3,715	3,665
Non-deductible reserves	336	567
Amortization of intangibles	24	162
Other	1,730	662
Deferred tax assets	27,754	14,766
Deferred tax liabilities:
Expensing of housekeeping supplies	(4,375)	(4,678)
Depreciation of property and equipment	(1,913)	(1,745)
Other	(914)	(845)
Deferred tax liabilities	(7,202)	(7,268)
Net deferred tax assets	$ 20,552	$ 7,498