Income Tax Considerations (Schedule Of Reconciling Net Income Adjusted For Noncontrolling Interests To REIT Taxable Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Net income adjusted for noncontrolling interests	$ 174,352	$ 288,008	$ 220,262
Net loss (income) of taxable REIT subsidiary included above	340	(4,092)	(4,684)
Net income from REIT operations	174,692	283,916	215,578
Book depreciation and amortization including discontinued operations	145,940	150,616	157,665
Tax depreciation and amortization	(87,416)	(90,328)	(90,047)
Book/tax difference on gains/losses from capital transactions	(53,902)	(87,387)	(33,969)
Deferred/prepaid/above and below-market rents, net	(5,375)	(3,617)	(6,429)
Impairment loss from REIT operations including discontinued operations	1,536	942	474
Other book/tax differences, net	(1,679)	(6,399)	(9,695)
REIT taxable income	173,796	247,743	233,577
Dividends paid deduction	(174,628)	(247,743)	(233,577)
Dividends paid in excess of taxable income	(832)	0	$ 0
Designated dividends	$ 114,000	$ 67,700