Real Estate Investments (Details Narrative)								3 Months Ended		6 Months Ended
	Apr. 06, 2018 USD ($) ft² a	Jan. 22, 2018 USD ($) ft² a	Dec. 22, 2017 USD ($)	Dec. 18, 2017 USD ($)	Nov. 30, 2017 USD ($) ft² a	Nov. 02, 2017 USD ($) ft² a $ / shares	Oct. 31, 2016 USD ($) ft² a	Mar. 31, 2018 USD ($) ft² a	Mar. 31, 2017 USD ($)	Mar. 31, 2018 USD ($) ft² a	Mar. 31, 2017 USD ($) ft²	Sep. 30, 2017 a
Transaction costs										$ 440,000
Total square foot of property | a								19,928,000		19,928,000		18,790,000
Gain on real estate properties										$ 5,388,000
Percentage of gain on properties								105.00%		105.00%
Net gain on historic cost										$ 1,804,000
Percentage of net gain over the historic cost basis								21.00%		21.00%
Lease termination income								$ 0	$ 0	$ 210,261	$ 0
Weighted average lease maturity										7 years 9 months 18 days
Held marketable securities								$ 144,630,426		$ 144,630,426
Percentage of un depreciated assets										8.30%
Series C Cumulative Redeemable Preferred Stock [Member]
Cumulative redeemable preferred, stock dividend rate								6.125%		6.125%
Series A Cumulative Redeemable Preferred Stock [Member]
Cumulative redeemable preferred, stock dividend rate								7.625%		7.625%
Series B Cumulative Redeemable Preferred Stock [Member]
Cumulative redeemable preferred, stock dividend rate								7.875%		7.875%
FedEx Corporation [Member]
Percentage of real estate property leased										8.00%	6.00%
FedEx Corporation [Member] | Rental And Reimbursement Revenue [Member]
Percentage of aggregate rental and reimbursement revenue											6.00%
FedEx Corporation [Member] | Rental And Reimbursement Revenue [Member] | Fiscal Year 2018 [Member]
Percentage of aggregate rental and reimbursement revenue										7.00%
Fedex Ground Package System Inc. [Member]
Lease term						10 years
Cost of building expansion						$ 1,683,000
Lease expiration date description						extended the prior lease expiration date from April 2024 to October 2027
Increase in rent						$ 184,000
Rent prior to expansion						$ 1,533,000
Rent prior to expansion, per square foot | $ / shares						$ 4.67
Rent increase to after expansion						$ 1,717,000
Rent increase to after expansion, per square foot | $ / shares						$ 5.24
Kansas City, MO (Kellogg) [Member]
Total square foot of property | a								65,067		65,067
Value of property sold				$ 4,900,000
Proceeds from sale of property				$ 4,602,000
Percentage of weighted average lease termination income										80.00%
Kansas City, MO (Kellogg) [Member] | July 31, 2018 [Member]
Area of property | ft²								65,057		65,057
Orangeburg NY [Member]
Total square foot of property | ft²								50,400		50,400
Value of property sold			$ 6,170,000
Proceeds from sale of property			$ 5,898,000
Kansas City, MO (Kellogg) and Orangeburg [Member]
Lease termination income										$ 210,000
Ft. Myers [Member]
Total square foot of property | ft²								87,500		87,500
Colorado Springs, CO [Member]
Total square foot of property | ft²								68,370		68,370
Fedex And Fedex Subsidiaries [Member]
Square feet of real estate property leased | ft²										9,513,000	8,187,000
Weighted average lease maturity										8 years 6 months
Percentage of real estate property leased										48.00%	49.00%
Percentage of rental space and tenant account, description										no other tenant accounted for 5% or more of our total rental space
Fedex And Fedex Subsidiaries [Member] | Rental And Reimbursement Revenue [Member]
Percentage of rental space and tenant account, description										no other tenant accounted for 5% or more of our total rental	no other tenant accounted for 5% or more of our total rental
Fedex And Fedex Subsidiaries [Member] | Rental And Reimbursement Revenue [Member] | Fiscal Year 2018 [Member]
Percentage of aggregate rental and reimbursement revenue										60.00%
Fedex And Fedex Subsidiaries [Member] | Rental And Reimbursement Revenue [Member] | Fiscal Year 2017 [Member]
Percentage of aggregate rental and reimbursement revenue											59.00%
Fedex Corporation Subsidiaries Member [Member]
Percentage of real estate property leased										40.00%	43.00%
Fedex Corporation Subsidiaries Member [Member] | Rental And Reimbursement Revenue [Member] | Fiscal Year 2018 [Member]
Percentage of aggregate rental and reimbursement revenue										53.00%
Fedex Corporation Subsidiaries Member [Member] | Rental And Reimbursement Revenue [Member] | Fiscal Year 2017 [Member]
Percentage of aggregate rental and reimbursement revenue											53.00%
Industrial Buildings [Member] | FedEx Corporation [Member]
Purchase of industrial building | ft²						121,683
Area of property | a						16.2
Percentage of building area leased						100.00%
Lease term						15 years
Lease term expiration period						Aug. 31, 2032
Purchase price of industrial building						$ 21,872,170
Mortgage loan amortization period						15 years
Face amount of mortgages						$ 14,200,000
Mortgage loans on real estate, interest rate						4.23%
Annual rental income over the remaining term of lease						$ 1,315,000
Industrial Buildings [Member] | Amazon.com Services, Inc [Member]
Purchase of industrial building | ft²					300,000
Area of property | a					123
Percentage of building area leased					100.00%
Lease term					10 years
Lease term expiration period					Oct. 31, 2027
Purchase price of industrial building					$ 30,250,000
Mortgage loan amortization period					18 years
Face amount of mortgages					$ 19,600,000
Mortgage loans on real estate, interest rate					3.64%
Annual rental income over the remaining term of lease					$ 1,884,000
Mortgage loan period					10 years
Industrial Buildings [Member] | Shaw Industries, Inc [Member]
Purchase of industrial building | ft²		831,764
Area of property | a		62.4
Percentage of building area leased		100.00%
Lease term		10 years
Lease term expiration period		Sep. 30, 2027
Purchase price of industrial building		$ 57,483,636
Mortgage loan amortization period		14 years
Face amount of mortgages		$ 33,300,000
Mortgage loans on real estate, interest rate		3.53%
Annual rental income over the remaining term of lease		$ 3,551,000
Industrial Buildings [Member] | B. Braun Medical Inc. [Member]
Purchase of industrial building | ft²	399,440
Area of property | a	27.5
Percentage of building area leased	100.00%
Lease term	10 years
Lease term expiration period	Apr. 01, 2028
Purchase price of industrial building	$ 30,750,540
Mortgage loan amortization period	15 years
Face amount of mortgages	$ 19,500,000
Mortgage loans on real estate, interest rate	4.25%
Annual rental income over the remaining term of lease	$ 2,128,000
Industrial Buildings [Member] | White Bear Lake, MN [Member]
Area of property | a							4.78
Proceeds from sale of property							$ 4,126,000
Sale of industrial building | ft²							59,425