Income Taxes (Tax Effects of Temporary Differences and Carryforwards Included in Net Deferred Tax Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
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	$ (60,494)	$ (257,373)	$ (269,758)
Operating loss and interest deduction carryforwards	124,606	136,771	133,243
Expense accruals and other	10,516	7,380	11,910
Valuation allowance	(127,279)	(40,114)	(80,614)
Net deferred tax liabilities	(52,651)	(153,336)	(205,219)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 54,400	57,700
Interest Expense Limitation due to Tax Cuts and Jobs Act of 2017
Income Tax Examination [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 57,700	$ 23,200