Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Deferred Charges, Goodwill And Other Assets) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Charges, Goodwill And Other Assets [Line Items]
Deferred leasing costs		$ 239,690	$ 239,138
Deferred financing costs		23,723	24,042
Deferred charges, gross		263,413	263,180
Accumulated amortization		(126,816)	(122,358)
Deferred charges, net		136,597	140,822
Notes receivable	[1]	13,496	21,491
In-place lease values, related intangibles and other assets, net		10,931	6,565
Goodwill		2,945	2,945
Prepaid expenses and other assets, net	[2]	49,408	32,827
Total deferred charges, goodwill and other assets, net		213,377	204,650
Lease revenue		487,041	516,727	$ 540,165
Acquired Above And Below Market Lease Intangibles [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Lease revenue		200	$ 700	$ 1,500
Acquisition-related Costs [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Deposits for acquisitions and developments		15,100
Mortgage Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable		$ 10,400
Spread over LIBOR		6.00%
Interest-Free Notes Receivable [Member]
Deferred Charges, Goodwill And Other Assets [Line Items]
Notes receivable		$ 3,100

[1] Includes as of December 31, 2015: a mortgage receivable for $10.4 million which bears interest at LIBOR plus six percent and matures in August 2016; and an interest-free note receivable with a net present value of $3.1 million and matures in April 2023. The Company believes these balances are fully collectible.

[2] Includes as of December 31, 2015, deposits of $15.1 million for acquisitions and developments.