Investment in Real Estate (Details 4) (Level 3 Fair Value Measurements [Member], 3rd Party Pricing [Member], USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2012
Level 3 Fair Value Measurements [Member] \| 3rd Party Pricing [Member]
Quantitative information about Level 3 fair value measurements
Fair Value Measurements	$ 24,069
Fair value inputs third party purchase contract or letters of intent

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant