Organization and Offering (Narratives ) (Details) (USD $)	0 Months Ended	1 Months Ended	15 Months Ended
	Apr. 07, 2011	Oct. 31, 2010	Jun. 30, 2012 tenant sqft property
Business [Abstract]
Number of Real Estate Properties			305
Number Of Tenants			47
Square Footage Of Real Estate Property			28,000,000
Number of self storage properties			49
Square footage of self storage properties			4,000,000
Proceeds from Issuance Initial Public Offering	$ 1,500,000,000
Maximum proceeds from issuance of shares in follow on public offering		$ 1,000,000,000	$ 781,300,000
Follow On Offering Stock shares, Par or Stated Value Per Share		$ 9.50
Percentage Of General And Limited Partnership Interest			99.985%
Operating Partnership Interest			0.015%