Transit Business Park Acquisition - Intangible asset amortization (Details) (USD $)	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Jun. 20, 2013 TransitBusinessPark
In-place leases initial value							$ 806,000
Above market leases initial value							48,000
Below market leases initial values							156,000
In-place Leases	0	27,000	74,000	237,000	347,000	121,000
Above Market Leases	0	11,000	11,000	11,000	12,000	3,000
Below Market Leases	$ 0	$ 0	$ 13,000	$ 51,000	$ 68,000	$ 24,000

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

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-Section 45

-Paragraph 28

-Subparagraph (b)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

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-Section 45

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-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 350

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