Discontinued Operations (Summary Of Income From Discontinued Operations And Related Realized And Unrealized Gains (Losses)) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Discontinued Operations [Abstract]
Total revenues				$ 33,601
Operating and other expenses				(13,454)
Depreciation and amortization				(8,218)
Interest expense				(118)
Income from discontinued operations				11,811
Loss from early extinguishment of debt				(703)
Impairments	[1]			(23,851)
Realized gains on disposition of rental property				83,371
Realized gains (losses) and unrealized losses on disposition of rental property and impairments, net				59,520
Total discontinued operations, net				70,628
Valuation allowance		$ 22,400
Sales proceeds		148,256	$ 319,239	$ 390,600
Gain (loss) on sale of property		53,261	54,848
Rental property held for sale, net		94,995	264,391
Accumulated depreciation		$ 1,464,482	$ 1,414,305

[1] Represents impairment charges recorded on certain properties prior to their sale.