Income Taxes and Distributions (Summary of Tax Effects of Taxable and Deductible Temporary Differences) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Tax effect of temporary differences
Investments and property, primarily differences in investment basis, depreciation and amortization, the basis of land assets and the treatment of interests and certain costs	$ (13,064)	$ (2,533)	$ (11,812)
Operating loss and interest deduction carryforwards	127,525	98,713	94,654
Expense accruals and other	43,056	48,804	25,146
Valuation allowance	(159,057)	(155,592)	(127,283)	$ (96,838)
Net deferred tax assets (liabilities)	$ (1,540)	$ (10,608)	$ (19,295)