Income Taxes and Distributions (Details 3) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Tax effect of temporary differences
Investments and property, primarily differences in investment basis, depreciation and amortization, the basis of land and the treatment of interests and certain costs	$ (11,812)	$ (7,089)	$ (30,564)
Operating loss and interest deduction carryforwards	94,654	82,469	75,455
Expense accruals and other	25,146	15,978	6,259
Valuation allowance	(127,283)	(96,838)	(98,966)	$ (85,207)
Deferred Tax Liabilities	$ (19,295)	$ (5,480)	$ (47,816)