Schedule III Properties And Accumulated Depreciation (Summary Of Accumulated Depreciation And Amortization) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance, beginning of year	$ 1,565,996	$ 1,206,017	$ 900,044
Additions during period (depreciation and amortization expense)	413,652	386,935	305,973
Deductions during period (dispositions and assets held for sale)	(105,594)	(26,956)
Balance, end of year	$ 1,874,054	$ 1,565,996	$ 1,206,017