Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable and Accrued Liabilities, Current [Abstract]
Salaries and wages	$ 88,425	$ 91,784
Insurance reserves	61,150	63,309
Vacation	37,109	40,281
Real estate taxes	25,302	30,743
Interest	15,458	13,745
Accrued utilities	8,883	10,807
Taxes payable	2,782	2,636
Lease payable	1,532	11,942
Other	57,586	64,719
Total	$ 298,227	$ 329,966