Income Taxes - Significant Components of Federal and State Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for doubtful accounts	$ 13,376	$ 14,599
Deferred compensation	8,074	7,350
Accrued insurance claims	4,902	3,715
Non-deductible reserves	489	336
Amortization of intangibles	0	24
Other	1,641	1,730
Deferred tax assets	28,482	27,754
Deferred tax liabilities:
Expensing of housekeeping supplies	(3,796)	(4,375)
Amortization of intangibles	218	0
Depreciation of property and equipment	(1,969)	(1,913)
Leases	(96)	0
Other	(2,039)	(914)
Deferred tax liabilities	(8,118)	(7,202)
Net deferred tax assets	$ 20,364	$ 20,552