Investments in Real Estate (Details) (USD $) In Millions, unless otherwise specified		3 Months Ended
	Mar. 31, 2012	Mar. 31, 2012 Convergence Business Park [Member]		Mar. 14, 2012 Savvis Joint Venture Property, Hong Kong [Member] sqft
Business Acquisition [Line Items]
Acquisition, Date Acquired		Feb. 22, 2012	[1]
Acquisition, Amount		$ 123.0	[1]
Number of buildings	8
Square Footage of Real Estate Property				165,000

[1] Convergence Business Park is comprised of eight buildings along with undeveloped land. It is considered one property for our property count.