Real Property Acquisitions and Development (Details Textual) (USD $)	9 Months Ended				9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Strategic Medical Office Partnership [Member]	Dec. 31, 2010 Strategic Medical Office Partnership [Member] Property	Sep. 30, 2011 Genesis Acquisition [Member]	Mar. 31, 2011 Genesis Acquisition [Member]	Mar. 31, 2011 Genesis Acquisition [Member] Minimum [Member]	Mar. 31, 2011 Genesis Acquisition [Member] Minimum [Member] 7-15 year [Member]	Mar. 31, 2011 Genesis Acquisition [Member] Maximum [Member]	Mar. 31, 2011 Genesis Acquisition [Member] Maximum [Member] 7-15 year [Member]	Sep. 30, 2011 Silverado Partnership [Member]	Mar. 31, 2011 Silverado Partnership [Member] Facility Property	Sep. 30, 2011 Benchmark partnership [Member]	Mar. 31, 2011 Benchmark partnership [Member] Property
Real Property Acquisitions and Development (Textual) [Abstract]
Number of properties acquired of substantially all of the real estate assets	244	59			147
Total purchase price						$ 2,475,144,000
Cash consideration of capital lease obligation						2,400,000,000
Allocated on preliminary basis to land and land improvements			10,240,000			144,091,000					11,170,000		60,440,000
Allocated on preliminary basis to buildings and improvements			170,886,000			2,331,053,000					173,841,000		794,886,000
Capital lease obligations						75,144,000
Rent received from master lease					198,000,000
Increase in master lease agreement rent							1.75%	1.50%	3.50%	3.00%
Number of properties in portfolio												18		34
Initial term of master lease						15 years
Investment made by partnership in number of properties				17
Controlling interest in number of properties				11
Number of properties under partnership not owned by company				6
Master lease agreement term							2 years		6 years
Percentage of interest owned by company in partnership												95.40%		95.00%
Percentage of interest owned by minority												4.60%		5.00%
Number of previous facilities under partnership owned by company												6
Number of facilities under partnership previously owned by partner												12
Contribution by the company for the formation of the partnership												163,368,000		383,356,000
Real property acquisitions and development (Additional Textual) [Abstract]
Capital lease obligations included in assumed other items, net	$ 75,144,000