Income Taxes Deferred (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Accrued expenses	$ 22,756	$ 16,500
Allowance for doubtful accounts	12,312	11,090
Tax credits	3,201	3,334
Insurance	5,667	5,135
Deferred Tax Assets, Gross	43,936	36,059
Valuation allowance	(791)	(530)
Total deferred tax assets	43,145	35,529
State taxes	(475)	(911)
Depreciation and amortization	(28,496)	(18,248)
Prepaid expenses	(2,524)	(3,625)
Total deferred tax liabilities	(31,495)	(22,784)
Net deferred tax assets	$ 11,650	$ 12,745