Income Tax Considerations (Schedule Of Reconciling Net Income Adjusted For Noncontrolling Interests To REIT Taxable Income) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Income Tax Disclosure [Abstract]
Net income adjusted for noncontrolling interests	$ 288,008,000		$ 220,262,000		$ 146,640,000
Net (income) loss of taxable REIT subsidiary included above	(4,092,000)		(4,684,000)		11,457,000
Net income from REIT operations	283,916,000		215,578,000		158,097,000
Book depreciation and amortization including discontinued operations	150,616,000		157,665,000		148,413,000
Tax depreciation and amortization	(90,328,000)		(90,047,000)		(92,797,000)
Book/tax difference on gains/losses from capital transactions	(87,387,000)		(33,969,000)		(55,242,000)
Deferred/prepaid/above and below-market rents, net	(3,617,000)		(6,429,000)		(4,264,000)
Impairment loss from REIT operations including discontinued operations	942,000		474,000		11,396,000
Other book/tax differences, net	(6,399,000)		(9,695,000)		1,430,000
REIT taxable income	247,743,000		233,577,000		167,033,000
Dividends paid deduction	(247,743,000)	[1]	(233,577,000)	[1]	(173,202,000)	[1]
Dividends paid in excess of taxable income	0		0		(6,169,000)
Designated dividends	$ 114,000,000		$ 67,700,000

[1] For 2014 and 2013, the dividends paid deduction includes designated dividends of $114.0 million and $67.7 million from 2015 and 2014, respectively.