Subsequent Events (Details Narrative) - Subsequent Event [Member]	Apr. 08, 2016 USD ($) ft²	Apr. 05, 2016 $ / shares	Apr. 19, 2016 USD ($) ft²
Subsequent Event [Line Items]
Dividend declared per share | $ / shares		$ 0.16
Declaration date		Apr. 05, 2016
Dividends payable, date to be paid		Jun. 15, 2016
Record date		May 16, 2016
Industrial Building [Member]
Subsequent Event [Line Items]
Sale of vacant buildings | ft²			59,425
Sale of buildings net book vale			$ 4,272,000
Total acres of property | ft²			4.78
Industrial Building [Member] | Fedex Ground Package System Inc. [Member]
Subsequent Event [Line Items]
Purchase of industrial building (square foot) | ft²	210,445
Percentage of building area leased	100.00%
Lease term expiration period	Aug. 31, 2030
Purchase price of industrial building	$ 30,662,080
Mortgage loan amortization period	15 years
Face amount of mortgages	$ 20,221,000
Mortgage loans on real estate, interest rate	3.67%
Annual rental income over the remaining term of lease	$ 1,962,000
Series A Preferred Shareholders [Member]
Subsequent Event [Line Items]
Dividend declared per share | $ / shares		$ 0.4765625
Declaration date		Apr. 05, 2016
Dividends payable, date to be paid		Jun. 15, 2016
Record date		May 16, 2016
Series B Preferred Shareholders [Member]
Subsequent Event [Line Items]
Dividend declared per share | $ / shares		$ 0.4921875
Declaration date		Apr. 05, 2016
Dividends payable, date to be paid		Jun. 15, 2016
Record date		May 16, 2016