The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 44

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16265-109275

Name:	us-gaap_AcquiredFiniteLivedIntangibleAssetWeightedAverageUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

Real Estate And Loans Receivable (List Of Assets Purchased As Part Of Acquisitions) (Details) (USD $) In Thousands, unless otherwise specified									12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Land [Member]	Dec. 31, 2010 Land [Member]	Dec. 31, 2009 Land [Member]	Dec. 31, 2011 Buildings [Member]	Dec. 31, 2010 Buildings [Member]	Dec. 31, 2011 Intangible Lease Assets-Subject To Amortization [Member]	Dec. 31, 2010 Intangible Lease Assets-Subject To Amortization [Member]
Real Estate Assets Purchased As Part Of Acquisitions [Line Items]
Significant acquisitions and disposals of acquisition				$ 19,705	$ 8,227	$ 421	$ 220,769	$ 119,626	$ 20,630	$ 9,955
Weighted-average useful life of acquired intangible assets (in years)									13.9	19.4
Total	$ 261,104	$ 137,808	$ 421