Schedule III Properties And Accumulated Depreciation (Summary Of Accumulated Depreciation And Amortization) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule III Properties And Accumulated Depreciation [Abstract]
Balance, beginning of year	$ 1,206,017	$ 900,044	$ 660,700
Additions during period (depreciation and amortization expense)	386,935	305,973	239,344
Deductions during period (dispositions and write-off of tenant improvements)	(26,956)
Balance, end of year	$ 1,565,996	$ 1,206,017	$ 900,044