Significant Concentrations of Credit Risk (Details Narrative)	12 Months Ended
	Sep. 30, 2016 USD ($) ft²	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Concentration Risk [Line Items]
Total property (in square feet)	16,010,000
Percentage of marketable securities to undepreciated assets	5.30%
Securities Available for sale at fait value | $	$ 73,604,894
FDX and Subsidiaries [Member]
Concentration Risk [Line Items]
Leases percentage of total property	49.00%	46.00%	44.00%
FDX and Subsidiaries [Member] | Rental And Reimbursement Revenue [Member]
Concentration Risk [Line Items]
Description of total rentable space leased	No other tenant accounted for 5% or more of the Company's total Rental and Reimbursement revenue .	No other tenant accounted for 5% or more of the Company's total Rental and Reimbursement revenue .	No other tenant accounted for 5% or more of the Company's total Rental and Reimbursement revenue .
Rental and reimbursement revenue | $	$ 52,793,000	$ 41,954,000	$ 35,007,000
Rental and reimbursement revenue, percentage	56.00%	54.00%	54.00%
Fdx [Member]
Concentration Risk [Line Items]
Leases percentage of total property	7.00%	8.00%	10.00%
Fedex Corporation [Member]
Concentration Risk [Line Items]
Total property (in square feet)	7,584,000
Concentration risk based on square feet, percentage	47.00%
Fdx [Member]
Concentration Risk [Line Items]
Leases percentage of total property	6.00%
FDX and Subsidiaries [Member]
Concentration Risk [Line Items]
Leases percentage of total property	41.00%
FDX And Subsidiaries And Milwaukee Electric Tool Corporation [Member]
Concentration Risk [Line Items]
Total property (in square feet)	862,000
Fedex And Fedex Subsidiaries [Member]
Concentration Risk [Line Items]
Description of total rentable space leased	No other tenant accounted for 5% or more of the Company's total Rental and Reimbursement revenue .	No other tenant accounted for 5% or more of the Company's total Rental and Reimbursement revenue .	No other tenant accounted for 5% or more of the Company's total Rental and Reimbursement revenue .