Schedule III Properties And Accumulated Depreciation (Summary Of Accumulated Depreciation And Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance, beginning of year	$ 1,874,054	$ 1,565,996	$ 1,206,017
Additions during period (depreciation and amortization expense)	429,057	413,652	386,935
Deductions during period (dispositions and assets held for sale)	(51,843)	(105,594)	(26,956)
Balance, end of year	$ 2,251,268	$ 1,874,054	$ 1,565,996