Income Taxes (Tax Effects of Temporary Differences and Carryforwards Included in Net Deferred Tax Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Examination [Line Items]
Property, primarily differences in depreciation and amortization, the tax basis of land assets and the treatment of interests and certain costs	$ (257,373)	$ (269,758)	$ (300,395)
Operating loss and interest deduction carryforwards	136,771	133,243	146,732
Expense accruals and other	7,380	11,910	12,890
Valuation allowance	(40,114)	(80,614)	(109,319)
Deferred tax assets, net	0	(922)	14,752
Deferred Tax Liabilities, Net	153,336	205,219	250,092
Research and Innovation Center
Income Tax Examination [Line Items]
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets	0	0	19,262
Other Segments [Member]
Income Tax Examination [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	$ 0	$ 922	$ 4,510