Schedule III Properties And Accumulated Depreciation (Summary Of Accumulated Depreciation And Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance, beginning of year	$ 3,238,227	$ 2,668,509	$ 2,251,268
Additions during period (depreciation and amortization expense)	714,336	612,970	461,506
Deductions during period (dispositions and assets held for sale)	(17,296)	(43,252)	(44,265)
Balance, end of year	$ 3,935,267	$ 3,238,227	$ 2,668,509