Real Property Acquisitions and Development (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Summary of real property investment activity
Total cash invested in real property	$ 1,850,578	$ 570,200
Development projects:
Total development projects	127,853	117,535
Expansion projects	7,631	240
Total construction in progress conversions	135,484	117,775
Medical facilities [Member]
Development projects:
Total development projects	60,536	93,676
Seniors Housing Facilities Triple Net [Member]
Development projects:
Total development projects	$ 67,317	$ 23,859

The cash outflow from the acquisition of a piece of land and anything permanently fixed to it, including buildings, structures on it and so forth, and payments to develop real estate assets by adding improvements on or to a parcel of land. Such improvements may include drainage, utilities, subdividing, access, buildings, and any combination of these elements. Including real estate intended to generate income for the owner; excluding real estate acquired for use by the owner.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 17

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration