Business (Narratives) (Details) (USD $)	1 Months Ended	9 Months Ended
	Sep. 30, 2014 tenant sqft property	Sep. 30, 2014 tenant sqft property	Dec. 31, 2013
Real Estate Properties
Share issued in public offering, shares	4,600,000
Additional disclosures
Number of real estate properties	688	688
Number of tenants	215	215
Square footage of real estate properties	80,800,000	80,800,000
Occupancy rate		98.10%
Common stock, per share value	$ 0.001	$ 0.001	$ 0.001
Share price	$ 64.00	$ 64.00
Managed REITs
Additional disclosures
Number of real estate properties	384	384
Number of tenants	150	150
Square footage of real estate properties	40,900,000	40,900,000
Occupancy rate		99.90%
Managed REITs | Operating real estate
Additional disclosures
Number of real estate properties	105	105
Square footage of real estate properties	11,000,000	11,000,000