Variable Interest Entities (Summary Of Consolidated Variable Interest Entities) (Details) (Consolidated Variable Interest Entities [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Consolidated Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Maximum Risk of Loss	$ 137,912	[1]	$ 138,176	[1]
Assets held by VIEs	303,294		309,387
Assets held as collateral for debt	$ 246,888		$ 250,105

[1] The maximum risk of loss has been determined to be limited to our guaranties of debt for each real estate joint venture.