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, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Net income adjusted for noncontrolling interests	$ 335,274	$ 238,933	$ 174,352
Net loss (income) of taxable REIT subsidiary included above	4,220	(14,497)	340
Net income from REIT operations	339,494	224,436	174,692
Book depreciation and amortization	162,964	162,534	145,940
Tax depreciation and amortization	(95,512)	(104,734)	(87,416)
Book/tax difference on gains/losses from capital transactions	6,261	(64,917)	(53,902)
Deferred/prepaid/above and below-market rents, net	(11,146)	(13,114)	(5,375)
Impairment loss from REIT operations	5,071	369	1,536
Other book/tax differences, net	(244)	(2,694)	(1,679)
REIT taxable income	406,888	201,880	173,796
Dividends paid deduction	(406,888)	(201,880)	(174,628)
Dividends paid in excess of taxable income	0	0	$ (832)
Designated dividends	$ 112,800	$ 16,800