Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Accrued insurance	$ 28,600	$ 25,900
Operating loss carryforwards and tax credits	70,500	67,700
Compensation and benefits	16,800	15,200
Bad debt	900	2,400
Other	11,500	8,400
Valuation allowance	(48,800)	(40,600)
Total deferred tax assets	79,500	79,000
Deferred tax liabilities:
Property and equipment	179,500	146,300
Goodwill	49,600	55,600
Other intangible assets	35,000	28,100
Gain on remeasurement of equity investee	7,000	7,100
Revenue recognition	20,600	21,600
Investments in unconsolidated entities	74,000	67,900
Other	10,100	16,100
Total deferred tax liabilities	375,800	342,700
Net deferred tax liabilities	$ (296,326)	$ (263,687)