Real Estate Investments (Schedule of Annualized Rental Income by Major Tenants) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Citizens Bank [Member]
Revenue, Major Customer [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	28.70%	62.90%
John Deere [Member]
Revenue, Major Customer [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	10.00%
Home Depot [Member]
Revenue, Major Customer [Line Items]
Entity-Wide Revenue, Major Customer, Percentage		21.10%
GSA [Member]
Revenue, Major Customer [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	11.60%