Basis and Summary of Significant Accounting Policies - Components of Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Prepaid Expenses	$ 37,981	$ 31,509
Prepaid Insurance	33,370	36,735
Assets Held for Sale	9,626	10,118
Deferred Tax Asset	7,556	11,589
Other Assets	27,822	26,548
Prepaid Expenses and Other Assets	$ 116,355	$ 116,499