Other Real Estate Property Investments (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Acquisition
Consideration, Cash Paid	$ 10,970,000	$ 113,790,000
Consideration, Noncontrolling Interest	80,000	1,500,000
Consideration, Debt Assumed		48,252,000
Assets Acquired, Real Estate	10,580,000	152,801,000
Assets Acquired, Net Intangibles	470,000	10,741,000
Life science
Acquisition
Consideration, Cash Paid	7,970,000	84,047,000
Consideration, Noncontrolling Interest	80,000
Consideration, Debt Assumed		48,252,000
Assets Acquired, Real Estate	7,580,000	126,610,000
Assets Acquired, Net Intangibles	470,000	5,689,000
Number of facilities placed into service		2
The square footage of facilities placed in service		88,000
Hospital
Acquisition
Consideration, Cash Paid	3,000,000
Assets Acquired, Real Estate	3,000,000
Medical office
Acquisition
Consideration, Cash Paid		29,743,000
Consideration, Noncontrolling Interest		1,500,000
Assets Acquired, Real Estate		26,191,000
Assets Acquired, Net Intangibles		5,052,000
Life science and medical office
Acquisition
Payments to acquire productive assets	$ 79,000,000	$ 54,000,000