Real Estate And Accumulated Depreciation (Total Cost Of The Properties) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at beginning of year	$ 4,399,850		$ 4,688,526	$ 4,777,794
Additions at cost	279,624		310,454	180,956
Retirements or sales	(232,823)		(608,466)	(123,252)
Property held for sale	(155,017)		0	(94,761)
Property transferred from held for sale	0		18,090	0
Impairment loss	(2,358)		(8,754)	(52,211)
Balance at end of year	$ 4,289,276	[1]	$ 4,399,850	$ 4,688,526

[1] The tax basis of our net fixed asset exceeds the book value by approximately $88.0 million at December 31, 2013