Summary of Significant Accounting Policies Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Assets [Abstract]
Other Receivables	$ 14,981	$ 15,698
Servicing Asset	7,821	11,443
Prepaid Expense	9,022	11,227
Prepaid Land Acquisition Costs	5,634	4,740
Other Assets, Miscellaneous	23,677	19,818
Other Assets	$ 61,135	$ 62,926