Basis and Summary of Accounting Policies - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Accounts Payable	$ 52,063	$ 71,941
Accrued Insurance Costs	43,138	47,649
Accrued Salaries and Benefits	46,266	41,612
Income Taxes Payable	37,663	3,592
Accrued Real Estate and Sales Taxes	30,397	32,986
Deferred Rent	31,211	31,859
Other Accrued Expenses and Liabilities	66,314	68,127
Accounts Payable and Accrued Liabilities	$ 307,052	$ 297,766