Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014
Business Overview:
Gross investment amount, total	$ 3,200,000,000	$ 3,200,000,000
Number of real estate properties	202	202
Total number of company owned real estate properties	200	200
Number of states that the Company owns real estate in, whole units	29	29
Square footage of owned real estate properties	14,300,000	14,300,000
Approximate square feet for which Nationwide property management services provided by company	9,700,000	9,700,000
Interest and Other Income, Net [Member]
Interest and Other Income, Net [Abstract]
Reimbursement of prior period operating expenses	$ 1,900,000	$ 1,900,000