Business (Narratives) (Details)	12 Months Ended
	Dec. 31, 2013 tenant sqft property	Dec. 31, 2012 Operating real estate property	Dec. 31, 2013 Managed REITs property
Additional disclosures
Number of real estate properties	418	21	1,021
Number of tenants	128
Square footage of real estate properties	39,500,000
Occupancy rate	98.90%